CN102292896A - Adaptive power control for wireless charging - Google Patents

Abstract

Exemplary embodiments are directed to wireless power transfer. A transmitter (202) generates an electromagnetic field at a resonant frequency through a transmit antenna to generate a coupling-mode region within a near field of the transmit antenna (204). The transmitter defines the start of a recurring period by on/off keying the electromagnetic field during a synchronization portion of the recurring period. During a power transmission portion of the recurring period, the transmitter couples portions of the electromagnetic field to different receive antennas of various receiver devices within the coupling-mode region. The transmitter also determines a power allocation for the various receiver devices disposed within the coupling-mode region within the recursion period, and adjusts a power level of near-field radiation in response to a power requirement received from the receiver devices.

Description

Adaptive Power Control for Wireless Charging

Claim of priority under 35 U.S.C. §119

This application claims priority under 35 U.S.C. § 119(e) to the following U.S. Provisional Patent Application:

US Provisional Patent Application 61/146,586, entitled "POWER SHARING FOR WIRELESS POWER DEVICES," filed January 22, 2009.

US Provisional Patent Application 61/151,156, entitled "DYNAMICPOWER CONTROL METHODOLOGY FOR WIRELESS CHARGING," filed February 9, 2009.

US Provisional Patent Application 61/183,907, entitled "ADAPTIVE POWER CONTROL FOR WIRELESSLY CHARGING DEVICES," filed June 3, 2009.

technical field

The present disclosure relates generally to wireless charging, and more specifically, to devices, systems, and methods related to distributing power to receiver devices that may be located in wireless power systems.

Background technique

Typically, each battery powered device, such as a wireless electronic device, requires its own charger and power source, typically an alternating current (AC) power outlet. Such a wired configuration becomes inconvenient to use when many devices need to be charged.

Methods are being developed that use over-the-air or wireless power transmission between a transmitter and a receiver coupled to an electronic device to be charged. These methods are broadly divided into two categories. One is based on the coupling of plane wave radiation (also called far-field radiation) between the transmit antenna and the receive antenna on the device to be charged. The receiving antenna collects the radiated power and rectifies it for charging the battery. The antenna generally has a resonant length in order to improve coupling efficiency. This approach suffers from the fact that power coupling decays rapidly as the distance between the antennas increases, so charging over reasonable distances (eg, less than 1-2 meters) becomes difficult. Additionally, because the transmitting system radiates plane waves, unintentional radiation can interfere with other systems if not properly controlled via filtering.

Other methods for wireless energy transmission technology are based on inductive coupling between a transmitting antenna embedded in, for example, a "charging" mat or surface, and a receiving antenna (plus a rectification circuit) embedded in the electronic device to be charged . The disadvantage of this approach is that the spacing between the transmit and receive antennas must be very close (eg, within a few millimeters). But this method does not have the ability to simultaneously charge multiple devices in the same area, which is usually very small and requires the user to accurately locate the device to a specific area.

For many wireless charging systems, the power transmitted from the source is fixed to a single level, so it is generally not possible to adjust the power level to accommodate devices with different maximum peak power levels. This limits the types of devices that can be charged. Another problem is that the fixed radiated power level cannot be adjusted according to the current battery level of the device. This wastes power because as the battery charges, it requires less and less power to complete the charge. Radiated power from the transmitter that is not absorbed by the device can increase the specific absorption rate (SAR) level. Fixed Transmitter Power Regulations: SAR requirements must be met for the worst case that occurs when the device being charged has poor coupling to the transmitter. Thus, devices with good coupling are limited to the power levels dictated by devices with poor coupling, which can lead to increased charging times for the devices. When charging multiple devices, a fixed transmit power implies that the same power level must apply to all devices, regardless of what charging level is optimal for each device. As stated earlier, this can result in wasted radiated power.

In the case of wireless power transmission, there is a need for apparatus and methods for transmitting and relaying wireless power with varying power levels and multiplexing times to increase power transmission efficiency.

Description of drawings

Figure 1 shows a simplified block diagram of a wireless power transfer system.

2 shows a simplified schematic diagram of a wireless power transfer system.

Figure 3 shows a schematic diagram of a loop antenna used in an exemplary embodiment of the invention.

Figure 4 is a simplified block diagram of a transmitter according to an exemplary embodiment of the present invention.

5 is a simplified block diagram of a receiver according to an exemplary embodiment of the present invention.

6 shows a simplified schematic diagram of a portion of a transmit circuit used to perform messaging between a transmitter and a receiver.

7 shows a simplified schematic diagram of a portion of the transmit circuit used to adjust the power level of the transmitter.

8 is a simplified block diagram of an AC/DC power supply that may be used to supply power to a transmitter.

Figure 9 illustrates a pulse width modulator (PWM) controller driving two N-channel transistors to create a synchronous buck converter.

Figure 10 illustrates an exemplary synchronous buck converter using a microcontroller.

11 illustrates a host device having a transmit antenna and including a receiver device placed nearby.

12A and 12B are simplified timing diagrams illustrating a messaging protocol for communication between a transmitter and receiver and for power transmission.

13A-13C illustrate a host device having a transmit antenna and including a receiver device placed in various positions relative to the transmit antenna.

14A-14G are simplified timing diagrams illustrating adaptive power control for delivering power to multiple receiver devices.

Detailed ways

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The detailed description set forth below in conjunction with the appended drawings is intended as a description of exemplary embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. The term "exemplary" is used throughout this description to mean "serving as an example, instance, or illustration" and should not necessarily be construed as preference or advantage over other exemplary embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the exemplary embodiments of the invention. It will be apparent to those skilled in the art that the exemplary embodiments of the invention may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the novelty of the exemplary embodiments presented herein.

The term "wireless power" is used herein to mean any form of energy associated with electric, magnetic, electromagnetic or otherwise transmitted between a transmitter and a receiver without the use of physical electromagnetic conductors.

FIG. 1 illustrates a wireless transmission or charging system 100 according to various exemplary embodiments of the invention. Input power 102 is provided to a transmitter 104 for generating a radiated field 106 for providing energy transfer. Receiver 108 is coupled to radiated field 106 and generates output power 110 for storage or consumption by a device (not shown) coupled to output power 110 . Both the transmitter 104 and the receiver 108 are separated by a distance 112 . In an exemplary embodiment, the transmitter 104 and the receiver 108 are configured according to a mutual resonance relationship, and when the resonant frequency of the receiver 108 is very close to the resonant frequency of the transmitter 104, when the receiver 108 is positioned in the radiation field 106 The transmission loss between the transmitter 104 and the receiver 108 is minimal when in the "near field" of .

The transmitter 104 further includes a transmit antenna 114 for providing means for energy transmission, and the receiver 108 further includes a receive antenna 118 for providing means for energy reception. The transmit and receive antennas are sized according to the application and the device to be associated with it. As stated, sexual energy transfer occurs by coupling most of the energy in the near field of the transmitting antenna to the receiving antenna rather than propagating most of the energy in the form of electromagnetic waves to the far field. While in this near field, a coupling mode may be created between the transmit antenna 114 and the receive antenna 118 . The region around antennas 114 and 118 where this near-field coupling can occur is referred to herein as the coupling-mode region.

2 shows a simplified schematic diagram of a wireless power transfer system. The transmitter 104 includes an oscillator 122 , a power amplifier 124 and a filter and matching circuit 126 . The oscillator is configured to generate a desired frequency, which is adjustable in response to an adjustment signal 123 . The oscillator signal may be amplified by the power amplifier 124 with an amplification amount responsive to the control signal 125 . A filter and matching circuit 126 may be included to filter out harmonics or other unwanted frequencies and to match the impedance of the transmitter 104 to the transmit antenna 114 .

The receiver 108 may include a matching circuit 132 and a rectifier and switching circuit 134 to generate a DC power output to charge a battery 136 (as shown in FIG. 2 ) or to power a device (not shown) coupled to the receiver. A matching circuit 132 may be included to match the impedance of the receiver 108 to the receive antenna 118 . Receiver 108 and transmitter 104 may communicate over a separate communication channel 119 (eg, Bluetooth, zigbee, cellular, etc.).

As illustrated in FIG. 3, the antenna used in the exemplary embodiment may be configured as a "loop" antenna 150, which may also be referred to herein as a "magnetic" antenna. Loop antennas may be configured to include an air core or a physical core (eg, a ferrite core). Air core loop antennas may be more tolerant to extraneous physical devices placed near the core. Additionally, air core loop antennas allow other components to be placed within the core area. In addition, the air magnetic core ring may more easily enable the placement of the receive antenna 118 (FIG. 2) in the plane of the transmit antenna 114 (FIG. 2) where the power in the coupled-mode region of the transmit antenna 114 (FIG. 2) Can be bigger.

As stated, the sexual energy transfer between the transmitter 104 and the receiver 108 occurs during a matched or nearly matched resonance between the transmitter 104 and the receiver 108 . However, even when the resonances between the transmitter 104 and receiver 108 are mismatched, energy may be transferred less efficiently. Energy transfer occurs by coupling energy from the near-field of a transmit antenna to a receive antenna residing in the neighborhood where this near-field is established, rather than propagating energy from the transmit antenna into free space.

The resonant frequency of a loop antenna or magnetic antenna is based on inductance and capacitance. Inductance in a loop antenna is generally only the inductance created by the loop, whereas capacitance is generally added to the inductance of the loop antenna to create a resonant structure at the desired resonant frequency. As a non-limiting example, capacitor 152 and capacitor 154 may be added to the antenna to create a resonant circuit that produces resonant signal 156 . Thus, for larger diameter loop antennas, the amount of capacitance required to induce resonance decreases as the diameter or inductance of the loop increases. Furthermore, as the diameter of the loop antenna or magnetic antenna increases, the near-field active energy transfer area increases. Of course, other resonant circuits are also possible. As another non-limiting example, a capacitor may be placed in parallel between the two terminals of the loop antenna. Additionally, those of ordinary skill in the art will recognize that, for a transmit antenna, the resonant signal 156 may be an input to the loop antenna 150 .

An exemplary embodiment of the invention includes coupling power between two antennas that are in the near field of each other. As stated, the near field is the area around an antenna where an electromagnetic field exists but may not propagate or radiate away from the antenna. It is usually limited to a volume close to the physical volume of the antenna. In an exemplary embodiment of the present invention, magnetic type antennas (e.g., single-turn loop antennas and multi-turn loop antennas) are used for both the transmit (Tx) and receive (Rx) antenna systems because the magnetic type Magnetic-type antennas tend to have a higher magnetic near-field amplitude than the electric near-field of an antenna such as a small dipole antenna. This allows for potentially higher coupling between the pair of antennas. Furthermore, "electric" antennas (eg, dipoles and monopoles) or a combination of magnetic and electric antennas are also contemplated.

Tx antennas can operate at sufficiently low frequencies and with sufficiently large antenna sizes to achieve good coupling to small Rx antennas at distances significantly greater than allowed by the earlier described far-field and inductive approaches (eg, >-4dB). If the Tx antenna is sized correctly, high coupling levels (e.g., -1 to -4dB).

FIG. 4 is a simplified block diagram of a transmitter 200 according to an exemplary embodiment of the present invention. The transmitter 200 includes a transmitting circuit 202 and a transmitting antenna 204 . In general, transmit circuitry 202 provides RF power to transmit antenna 204 by providing an oscillating signal that causes near-field energy to be generated around transmit antenna 204 . As an example, transmitter 200 may operate in the 13.56 MHz ISM band.

Exemplary transmit circuitry 202 includes fixed impedance matching circuitry 206 for matching the impedance (e.g., 50 ohms) of transmit circuitry 202 to transmit antenna 204; and a low-pass filter (LPF) 208 configured to reduce harmonic Emissions are reduced to a level that prevents self-interference of devices coupled to receiver 108 (FIG. 1). Other exemplary embodiments may include different filter topologies including, but not limited to, notch filters that attenuate certain frequencies while passing others, and may include adaptive impedance matching, which may be based on measurable emission metrics (for example, the output power to the antenna or the DC current drawn by the power amplifier). The transmit circuit 202 further includes a power amplifier 210 configured to drive an RF signal as determined by an oscillator 212 . The transmit circuitry may consist of discrete devices or circuits, or may consist of an integrated assembly. An exemplary RF power output from transmit antenna 204 may be approximately 2.5 to 8.0 watts.

The transmit circuit 202 further includes a controller 214 for enabling the oscillator 212 during a transmit phase (or duty cycle) for a particular receiver, for adjusting the frequency of the oscillator, and for adjusting the output power level. platform to implement a communication protocol for interacting with neighboring devices via receivers attached to them.

Transmit circuitry 202 may further include load sensing circuitry 216 for detecting the presence or absence of an active receiver in the vicinity of the near field generated by transmit antenna 204 . As an example, the load sensing circuit 216 monitors the current flowing to the power amplifier 210 , which is affected by the presence or absence of an active receiver in the vicinity of the near field generated by the transmit antenna 204 . Detection of a change in loading on power amplifier 210 is monitored by controller 214, which is used to determine whether to enable oscillator 212 to transmit energy to communicate with an active receiver.

Transmit antenna 204 may be implemented as an antenna strip with a thickness, width, and metal type selected to keep resistive losses low. In a conventional implementation, transmit antenna 204 may generally be configured for association with a larger structure such as a table, cushion, lamp, or other less portable configuration. Thus, transmit antenna 204 generally will not require "turns" in order to be of a practical size. An exemplary implementation of transmit antenna 204 may be "electrically small" (ie, a fraction of a wavelength) and tuned to resonate at lower usable frequencies by using capacitors to define the resonant frequency. In an exemplary application where the transmit antenna 204 may be relatively large in diameter or side length (if a square loop) (eg, 0.50 meters) relative to the receive antenna, the transmit antenna 204 will not necessarily require a large number of turns to obtain reasonable capacitance.

Transmitter 200 may aggregate and track information regarding the whereabouts and status of receiver devices that may be associated with transmitter 200 . Accordingly, the transmitter circuit 202 may include a presence detector 280, an enclosure detector 290, or a combination thereof connected to the controller 214 (also referred to herein as a processor). Controller 214 may adjust the amount of power delivered by amplifier 210 in response to the presence signals from presence detector 280 and enclosure detector 290 . The transmitter can receive power via a number of power sources, such as an AC/DC converter (not shown) to convert conventional AC power present in the building, to convert conventional DC power to a power source suitable for the transmitter 200. DC/DC converter (not shown) for the voltage of the 1000V, or may receive power directly from a conventional DC power source (not shown).

As a non-limiting example, presence detector 280 may be a motion detector to sense the initial presence of a device to be charged inserted in the transmitter's coverage area. After detection, the transmitter can be turned on and RF power received by the device can be used to trigger a switch on the Rx device in a predetermined manner, which in turn causes a change in the driving point impedance of the transmitter.

As another non-limiting example, presence detector 280 may be a detector capable of detecting humans, eg, through infrared detection, motion detection, or other suitable means. In some demonstrative embodiments, there may be rules that limit the amount of power that a transmit antenna can transmit at a particular frequency. In some cases, these rules are intended to protect humans from electromagnetic radiation. However, there may be environments where transmit antennas are placed in areas that are not or rarely occupied by humans (eg, garages, factory areas, workshops, and the like). If these environments are free of humans, it may be permissible to increase the transmit antenna's power output above nominal power limit regulations. In other words, controller 214 may adjust the power output of transmit antenna 204 to a regulated level or lower in response to the presence of a human, and will transmit The power output of antenna 204 is adjusted to a level above regulatory levels.

As a non-limiting example, the enclosure detector 290 (which may also be referred to herein as an enclosed compartment detector or an enclosed space detector) may be a device such as a sensing switch that is used to determine when the enclosure is closed. or open. When the transmitter is in an enclosure that is closed, the power level of the transmitter may be increased.

In an exemplary embodiment, a method by which the transmitter 200 does not remain on indefinitely may be used. In this case, the transmitter 200 may be programmed to switch off after a user-determined amount of time. This feature prevents the transmitter 200 (especially the power amplifier 210) from operating for a long time after the surrounding wireless devices are fully charged. This event can be attributed to a failure of the circuitry used to detect the signal sent from the repeater or receiving coil indicating that the device is fully charged. To prevent the transmitter 200 from automatically shutting off if another device is placed in its perimeter, the transmitter 200 auto shutoff feature may only be activated after a set period of lack of motion in its perimeter is detected. The user may be able to determine the inactivity time interval, and change the inactivity time interval if desired. As a non-limiting example, the time interval may be longer than that required to fully charge a particular type of wireless device assuming the device is initially fully discharged.

FIG. 5 is a simplified block diagram of a receiver 300 according to an exemplary embodiment of the present invention. The receiver 300 includes a receiving circuit 302 and a receiving antenna 304 . Receiver 300 is further coupled to device 350 for providing received power to device 350 . It should be noted that receiver 300 is illustrated as being external to device 350 , but it could be integrated into device 350 . In general, energy is propagated wirelessly to receive antenna 304 and then coupled to device 350 via receive circuitry 302 .

Receive antenna 304 is tuned to resonate at or near the same frequency as transmit antenna 204 (FIG. 4). Receive antenna 304 may be sized similarly to transmit antenna 204 , or may be sized differently based on the size of associated device 350 . As an example, device 350 may be a portable electronic device having a diameter or length dimension that is less than the length of the diameter of transmit antenna 204 . In this example, receive antenna 304 may be implemented as a multi-turn antenna in order to reduce the capacitance value of a tuning capacitor (not shown) and increase the impedance of the receive antenna. As an example, receive antenna 304 may be placed around the substantial circumference of device 350 in order to maximize the antenna diameter and reduce the number of loop turns (ie, windings) and inter-winding capacitance of the receive antenna.

Receive circuit 302 provides impedance matching with receive antenna 304 . Receive circuitry 302 includes power conversion circuitry 306 for converting received RF energy into charging power for use by device 350 . Power conversion circuitry 306 includes an RF/DC converter 308 and may also include a DC/DC converter 310 . RF/DC converter 308 rectifies the RF energy signal received at receive antenna 304 into non-AC power, and DC/DC converter 310 converts the rectified RF energy signal into an energy potential compatible with device 350 (e.g., a voltage ). A variety of RF/DC converters are contemplated, including partial and full rectifiers, regulators, bridges, doublers, and linear and switching converters.

The receiving circuit 302 may further include a switching circuit 312 for connecting the receiving antenna 304 to the power conversion circuit 306 or for disconnecting the power conversion circuit 306 . Disconnecting the receive antenna 304 from the power conversion circuit 306 not only discontinues charging the device 350, but also changes the "load" that the transmitter 200 (FIG. 2) "sees".

As disclosed above, the transmitter 200 includes a load sensing circuit 216 that detects fluctuations in the bias current provided to the transmitter power amplifier 210 . Accordingly, the transmitter 200 has a mechanism for determining when a receiver is present in the near field of the transmitter.

When multiple receivers 300 are present in the near field of a transmitter, it may be desirable to time multiplex the loading and unloading of one or more receivers to enable other receivers to more efficiently couple to the transmitter. Receivers may also be shaded to eliminate coupling to other nearby receivers or to reduce loading on nearby transmitters. This "offloading" of the receiver is also referred to herein as "cloaking". Furthermore, this switching between unloading and loading, controlled by the receiver 300 and detected by the transmitter 200, provides a communication mechanism from the receiver 300 to the transmitter 200, as explained more fully below. Additionally, a protocol enabling the sending of messages from the receiver 300 to the transmitter 200 may be associated with the handover. As an example, the switching speed may be about 100 microseconds.

In an exemplary embodiment, communication between the transmitter and receiver refers to device sensing and charging control mechanisms rather than conventional two-way communication. In other words, the transmitter uses on/off keying of the transmitted signal to adjust whether energy in the near field is available. The receiver interprets these energy changes as messages from the transmitter. From the receiver side, the receiver uses tuning and detuning of the receive antenna to adjust the amount of power being received from the near field. The transmitter can detect this difference in power used from the near field, and interpret these changes as messages from the receiver.

Receive circuitry 302 may further include signaling detector and beacon circuitry 314 to identify received energy fluctuations, which may correspond to informative signaling from the transmitter to the receiver. In addition, the signaling and beaconing circuit 314 can also be used to detect the transmission of reduced RF signal energy (i.e., a beacon signal) and rectify the reduced RF signal energy to a nominal power for waking up the RF signal within the receiving circuit 302. Unpowered or depleted circuitry in order to configure receiving circuitry 302 for wireless charging.

Receive circuitry 302 further includes a processor 316 for coordinating the processing of receiver 300 described herein (including control of switching circuitry 312 described herein). Shading of receiver 300 may also occur upon the occurrence of other events, including detection of an external wired charging source providing charging power to device 350 (eg, wall/USB power). In addition to controlling shading of the receiver, the processor 316 may also monitor the beacon circuit 314 to determine beacon status and extract messages sent from the transmitter. Processor 316 may also tune DC/DC converter 310 for improved performance.

In some demonstrative embodiments, receive circuit 320 may transmit signals to The controller issues power requirements (as explained more fully below). Based on these levels and the actual amount of power received from the transmitter, processor 316 may adjust the operation of DC/DC converter 310 to adjust its output in the form of adjusted current levels, adjusted voltage levels, or a combination thereof.

6 shows a simplified schematic diagram of a portion of a transmit circuit used to perform messaging between a transmitter and a receiver. In some exemplary embodiments of the invention, means for communication may be enabled between a transmitter and a receiver. In FIG. 6, a power amplifier 210 drives a transmit antenna 204 to generate a radiated field. The power amplifier is driven by a carrier signal 220 that oscillates at the desired frequency of the transmit antenna 204 . The transmit modulation signal 224 is used to control the output of the power amplifier 210 .

The transmit circuit may send a signal to the receiver by using an on/off keying process on the power amplifier 210 . In other words, the power amplifier 210 will drive the frequency of the carrier signal 220 outward on the transmit antenna 204 when the transmit modulation signal 224 is asserted. When the transmit modulation signal 224 is negated, the power amplifier will not drive any frequencies out on the transmit antenna 204 .

The transmit circuit of FIG. 6 also includes a load sense circuit 216 that supplies power to the power amplifier 210 and produces a receive signal 235 output. In load sensing circuit 216 , a voltage drop across resistor R _s results between power input signal 226 and power supply 228 to power amplifier 210 . Any change in the power consumed by the power amplifier 210 will cause a change in voltage drop, which will be amplified by the differential amplifier 230 . When the transmit antenna is in coupled mode with the receive antenna in the receiver (not shown in Figure 6), the amount of current drawn by the power amplifier 210 will change. In other words, if there were no coupled mode resonances for the transmit antenna 210, the power required to drive the radiated field would be the first amount. If there is a coupled mode resonance, the amount of power consumed by the power amplifier 210 will rise because a large amount of power is coupled to the receive antenna. Accordingly, receive signal 235 may indicate the presence of a receive antenna coupled to transmit antenna 235 and may also detect signals transmitted from the receive antenna. Additionally, a change in receiver current draw will be observable in the transmitter's power amplifier current draw, and this change can be used to detect the signal from the receive antenna.

Details of some exemplary embodiments of masking signals, beacon signals, and circuits for generating these signals can be found in the following U.S. utility model patent application: "Response Via Receive Antenna Impedance Modulation" filed on October 10, 2008. U.S. utility model patent application 12/249,873 to link signaling (REVERSE LINK SIGNALING VIA RECEIVE ANTENNA IMPEDANCEMODULATION); AWIRELESS CHARGING SYSTEM), "U.S. Utility Model Application No. 12/249,861, both of which are incorporated herein by reference in their entirety.

Details of exemplary communication mechanisms and protocols can be found in U.S. Utility Model Application 12/249,866, filed October 10, 2008, entitled "SIGNALING CHARGING IN WIRELESS POWER ENVIRONMENT," The content of the said application is hereby incorporated by reference in its entirety.

7 shows a simplified schematic diagram of a portion of the transmit circuit used to adjust the power level of the transmitter. In some exemplary embodiments, controller 214 may be coupled to voltage regulator 240 , current limiter 242 , or a combination of voltage regulator 240 and current limiter 242 to control the voltage at power input signal 226 relative to supplied DC input 415 . on the amount of power delivered. Additionally, some exemplary embodiments may include a current detector 252 and a voltage detector 250 coupled to the power input signal 226 and used to provide feedback to the controller regarding the consumption of power. The load sense circuit 216 of FIG. 6 is one example of a suitable current detector.

As stated earlier with reference to FIGS. 1, 2, and 4, the transmit circuit 202 and transmit antenna 204 can be used to deliver power to the receiver device that requires charging by placing it near the coupling mode region of the transmit antenna. device. In the exemplary embodiments discussed herein, the transmitter may cycle power sequentially to all receiver devices to be charged based on power level, time, and the like. The receiver device can communicate device power requirements and other information to the transmitter. With this power requirement information, the transmitter can tailor the amount of power delivered to each receiver device by adjusting the amount of power transmitted, adjusting the amount of time when power is transmitted, or a combination thereof.

The combination of voltage regulator 240 and current limiter 242 may be used to implement appropriate circuitry for adjusting the power level of the transmitter. An adjustable voltage regulator circuit may, for example, include an adjustable potentiometer, a rectifier, a (possible) smoothing circuit, and a (possible) bandgap reference circuit. Examples of some voltage regulator circuits suitable for use with embodiments of the invention are illustrated and discussed below with reference to FIGS. 8 , 9 and 10 .

A receiver device that needs to be charged may signal its power requirements (eg, in terms of current and voltage) to the transmitter. For example, a protocol may be included in which each receiver device wishing to charge signals its power rating, including its peak voltage and current levels. Alternatively, recommended levels of current and voltage can be signaled. Additionally, an identifier for each device to be charged may likewise be signaled.

Processor 214 may then control power delivered to power amplifier 210 ( FIG. 6 ), for example, via power input signal 226 .

In some demonstrative embodiments, voltage detector 250 may be included, for example, separately (as shown in FIG. 7 ) or as part of voltage regulator 240 . Voltage detector 250 forms a feedback path with controller 214 to adjust the power level on power input signal 226 . Thus, in conjunction with controlling the current, the controller 214 can adjust the level within the voltage regulator 240 within specified limits to provide optimal charging for the device to be charged. Thus, the optimal level can be set to not exceed the power rating of the device (as determined by the fact that power is the product of voltage and current).

In some demonstrative embodiments, current detector 252 may be included, for example, separately (as shown in FIG. 7 ) or as part of current regulator 242 . Voltage detector 250 forms a feedback path with controller 214 to adjust the power level on power input signal 226 . Thus, in conjunction with controlling the voltage, controller 214 can adjust the level within current limiter 242 within specified limits to provide optimal charging for the device to be charged. Thus, the optimal level can be set to not exceed the power rating of the device (as determined by the fact that power is the product of voltage and current).

Through current detector 252 and voltage detector 250, the power drawn by each receiver device may be monitored in conjunction with voltage and current detectors that provide threshold detection of power components (voltage or current). Accordingly, the controller 214 can adjust the voltage and current to different levels for each receiver device being charged throughout the charging process.

The receiver device may signal the need for power requirements via the wireless charging signaling protocol as discussed above. Additionally, a separate communication channel 119 (eg, Bluetooth, Zigbee, Cellular, etc.) may be used to signal the power requirement.

Exemplary embodiments of the present invention are directed to dynamic transmit radiated power level control for driving the power amplifier 210 (FIG. 6) through adaptive control using drive voltage, drive current, or a combination thereof. Changing the drive level changes the RF power output from the PA and (thus) the power transmitted to the receiving device being charged.

Some exemplary information used to define power levels may include:

1. The type of device and the optimum RF power level that the receiver device will be willing to see,

2. the current battery charge level of the device being charged, and

3. The RF power level each device is currently receiving from the transmission source.

Knowing the device type and its preferred RF power level for charging (item 1), the transmission source can be adjusted to this level during the time slot being charged, as explained more fully below. Thus, the level of power delivered to that device can be customized for each device independently without affecting any of the other devices. Additionally, knowledge of the current battery charge level of the device being charged (item 2) allows the radiated RF level to be optimized based on the device's current battery charge level. Both techniques help minimize the power that would normally be wasted when a fixed transmit power level is implemented.

In addressing RF safety concerns, comparing the power level absorbed by each device (item 3) with the power emitted from the transmitter gives an indication of the total power radiated to the local environment, which in turn is compared to the transmitter SAR level is proportional. This allows a device to maximize radiated power to each device based on the coupling ratio of each device to the transmitter, while still maintaining acceptable SAR levels. As a result, the power delivered to each device individually can be improved rather than being limited to a lower fixed power level mandated by devices with poor coupling to the transmitter. Finally, adjustable radiated power allows for a lower power beacon mode that reduces transmitter AC power consumption when not in charging mode, and also reduces interference with locally located electronic devices.

8, 9, and 10 illustrate exemplary circuits that may be used to regulate and adjust the power level of the power amplifier 210 and other transmit circuits 202. As shown in FIG. In FIG. 8, the AC/DC power supply 400 converts 120 volts AC 405 to various DC voltages that the transmitter may require to drive the transmit antenna 204 (e.g., 5 volts and 100 mA for the transmit circuit 202 to operate). auxiliary power, and 5 to 12 volts and 500 mA main power to operate the power amplifier 210).

AC/DC converter 410 generates intermediate DC voltage 415 (also referred to herein as "DC input") for circuit regulator 420 and PA regulator 450 . The circuit regulator 420 provides normal power 425 for the transmit circuit 202 and the PA regulator provides variable power levels of the power input signal 226 to drive the PA 210.

The AC/DC converter 410 can be, for example, a conventional "wall wart" that allows an Underwriters Laboratories (UL; Underwriter Laboratories) and Canadian Standards Association (CSA; Canadian Standards Association) approved power supply as the "wall wart" of the system. Certified” section while keeping costs down. Quasi-regulated (eg, about 10%) transformers are inexpensive and commercially available from a variety of vendors.

As a non-limiting example, circuit regulator 420 and PA regulator 450 may be implemented as buck voltage converters. The dual buck design of circuit regulator 420 and PA regulator 450 keeps efficiency high at the expense of additional switch mode controllers, field effect transistors (FETs), capacitors and inductors.

Thus, circuit regulator 420 may be a low power fixed output buck converter that provides 5 volts for controller 214 and other circuits as illustrated in FIG. 4 . PA regulator 450 may be a higher power variable output buck converter that supplies a varying voltage to the power amplifier to control the power output of the transmitter. The power amplifier supply 226 may be controlled by a control signal 452 from the transmit circuit 202 to the PA regulator 450, which varies the transmitted RF power, for example, within a range of about 50 milliwatts to about 5 watts.

FIG. 9 illustrates a PA regulator 450A implemented as a pulse width modulator (PWM) controller 460 (eg, Linear Technology LTC3851 ), driving two N-channel transistors to include a synchronous buck converter. A small inductor, resistor ladder, and output capacitor filter the output of the transistor to complete the buck converter. The buck converter converts and regulates the DC input voltage 415 into a DC output voltage 226 .

Power output may be controlled, for example, by a digital (programmable) potentiometer 465 controlled by control signal 452 . Control signal 452 may be driven by controller 214 (FIG. 4) such that DC output voltage 226 may be set to approximately, eg, 5 to 12 volts DC. The PA regulator 450A costs very little controller overhead and can be configured to have guaranteed loop stability under rapidly changing load conditions with over 90% efficiency.

Alternatively, FIG. 10 illustrates PA regulator 450B using microcontroller 470 as a synchronous buck converter. Microcontroller 470 may be dedicated to the synchronous buck converter function. However, in some exemplary embodiments, the controller 214 of the transmitter 200 (FIG. 4) may be used to synchronize the buck converter function with other functions it is performing. The buck converter converts and regulates the DC input voltage 415 into a DC output voltage 226 .

Therefore, the microcontroller 470 can directly drive the P-channel and N-channel FETs to provide switching control for the buck converter. A small inductor, resistor ladder, and output capacitor filter the output of the transistor to complete the buck converter. Feedback can be input directly to the A/D input of microcontroller 470 to operate as a voltage sense. Accordingly, control signal 452 may be embodied as a sampled version of the voltage on DC output 226 . Microcontroller 470 may compare the actual output on DC output 226 to the desired output and correct the PWM signal accordingly. Since the frequency may be much lower for a microcontroller 470 implementation, a larger inductor may be required, which is not a big issue in the transmitter. A microcontroller 470 implementation may be relatively inexpensive since no separate PWM controller is required.

As stated above, the benefits of allowing transmit power to be adjusted dynamically are the following:

1. Customization of power delivered to individual device types, thereby allowing more device types to be charged with a single charger design;

2. Avoiding wasted radiated power by allowing varying power levels to be delivered to multiple devices depending on the current battery charge level in a manner that does not affect the charging time of other devices;

3. Improved charging time by allowing radiated power levels based on individual device coupling levels to the transmitter in a manner that still meets SAR requirements; and

4. Reduced power consumption when the charger is not charging the device (beacon mode), and reduced interference with nearby electronic devices.

FIG. 11 illustrates a host device 510 having transmit circuitry 202 and transmit antenna 204 . Receiver device 520 is shown placed within the coupling-mode region of transmit antenna 204 . Although not illustrated, the receiver device may include a receive antenna 304 and receive circuitry 302 (as shown in FIG. 5 ). In FIG. 11, host device 410 is illustrated as a charging mat, but it could be integrated into furniture or building elements such as walls, ceilings, and floors. Furthermore, host device 510 may be an item such as a handbag, backpack, or briefcase with a built-in transmitter. Alternatively, the host device may be a portable transmitter (eg, a charging pack) specifically designed for a user to transport and charge the receiver device 520 .

As used herein, "coplanar" means that the transmitting and receiving antennas have substantially aligned planes (i.e., have surface normals pointing in substantially the same direction) and that the plane of the transmitting and receiving antennas is between No distance (or a small distance). As used herein, "coaxial" means that the transmitting and receiving antennas have substantially aligned planes (i.e., have surface normals pointing in substantially the same direction) and that the distance between the two planes is not zero, and furthermore, the surface normals of the transmitting and receiving antennas extend substantially along the same vector, or the two normals are stepped.

Coplanar placement can have relatively high coupling efficiency. However, the coupling may vary depending on where the receive antenna is placed relative to the transmit antenna. For example, coplanar placement points outside the transmit loop antenna may not couple as effectively as coplanar placement points inside the transmit loop antenna. Furthermore, coplanar placement points within the transmit loop antenna but at different locations relative to the loop antenna may have different coupling efficiencies.

Coaxial placement may have lower coupling efficiency. However, the coupling efficiency can be improved through the use of repeater antennas, such as in the patent application entitled "METHODAND APPARATUS FOR AN ENLARGED WIRELESS CHARGING AREA" filed on October 10, 2008 described in US Utility Patent Application 12/249,875, the contents of which are incorporated herein by reference in their entirety.

12A is a simplified timing diagram illustrating an exemplary messaging protocol for communication between a transmitter and receiver using the signaling techniques discussed above. In one exemplary approach, the signal from the transmitter to the receiver is referred to herein as the "forward link" and uses simple AM modulation between nominal power transmissions and lower power transmissions. Other modulation techniques are also contemplated. As a non-limiting example, signal presence may be interpreted as a "1" and signal absence as a "0" (ie, on/keying).

Reverse link signaling is provided by modulation of the power drawn by the receiving device, which can be detected by load sensing circuitry in the transmitter. As a non-limiting example, a higher power state may be interpreted as a 1 and a lower power state as a 0. It should be noted that the transmitter must be on to enable the receiver to perform reverse link signaling. Additionally, the receiver should not perform reverse link signaling during forward link signaling. Furthermore, if two receiving devices attempt to perform reverse link signaling at the same time, collisions may occur, which will make decoding difficult if it is possible for the transmitter to decode the appropriate reverse link signal.

Figure 12A illustrates a simple and low power form of the messaging protocol. The synchronization pulse 620 is repeated every recursion period 610 (approximately 1 second in the exemplary embodiment) to define the start of the recursion period. As a non-limiting example, the sync pulse on-time may be about 40 milliseconds. The recursive cycle 610 (with at least one sync pulse 620) may be repeated indefinitely while the transmitter is on. Note that "sync pulse" is a bit of a misnomer because sync pulse 620 may be a steady frequency during pulse period 620 . The synchronization pulse 620 may also include signaling at the resonant frequency by on/off keying discussed above and as illustrated by the “hatched” pulse 620 . FIG. 12A illustrates a minimum power state where power at the resonant frequency is supplied during sync pulse 420 and the transmit antenna is off during power cycle 650 . All receiver devices are allowed to receive power during sync pulse 420 .

12B illustrates a recursive cycle 610 with a sync pulse 620, a reverse link cycle 630, and a power cycle 650' in which the transmit antenna is on and fully powered by oscillating at the resonant frequency and no signaling is performed. make. The power cycle 450' may be segmented into different cycles for use with multiple receiver devices, as explained below. Figure 12B shows three power segments Pdl, Pd2, and Pdn for three different receiver devices.

The on/key communication protocol discussed above may be extended such that each receiver device is able to request charging and indicate desired power parameters as discussed above. Additionally, the receiver device may identify itself by a unique identifier, such as a serial number or a badge that associates the receiver device with a particular user. The request receiver device may also convey additional information such as the type of device (eg, camera, cell phone, media player, personal digital assistant).

Receiver information may include items such as a unique device identifier, device type, contact information, and information about user programming of the device. For example, a device may be a music player from a particular manufacturer that is stamped with the user's name. As another example, the device may be an electronic book with a specific serial number from a specific manufacturer, stamped with the user's name.

In addition to communicating using the on/off keying communication protocol discussed above, the receiver and transmitter may communicate over a separate communication channel 119 (eg, Bluetooth, Zigbee, Cellular, etc.). With a separate communication channel, the recursive cycle need not include any communication cycle and the entire time can be dedicated to the power cycle 650'. The transmitter can still allocate time slots to each receiver device (communicating on a separate communication channel) and each receiver device only gets its assigned power segment Pdn on the bus.

As described above, in many applications it may be important to be able to allocate a certain percentage of power between each of the powered receiver devices so that each receiver device is properly powered. In some cases, this will be an equal division of power between all receiver devices. In other situations, a receiver device may require more power (perhaps due to higher power tasks that it must periodically perform). In yet other situations, a receiver device may require less power (perhaps due to a fully charged battery). In such a situation, the system may wish to offload the receiver device's power distribution to other devices.

There are many methods for power sharing. One simple way is to have all receiver devices receive power simultaneously, thus sharing the power available in the wireless power environment. This approach is simple, cheap and robust, but it may have the disadvantage that in many RF/inductive charging environments, one receiver device may couple to the transmit antenna better than the other. As a result, most of the power is available to the first receiver device. Another disadvantage is that there is no way to "throttle" power for a receiver device with a fully charged battery.

Another way to distribute power among multiple receiver devices is time division multiplexing, where one receiver device is enabled to receive power at a time. All receiver devices that do not receive power are disabled from receiving power so that they do not interact with the RF/inductive environment. Time division multiplexing requires a controller that can distribute power among several powered devices, and can optionally make decisions on unequal distribution of power. As a non-limiting example, the transmitter may reduce the length or eliminate the power segment to a fully charged device. Time division multiplexing may have the disadvantage of losing some efficiency because the sum of the coupling efficiencies of all receiver devices receiving simultaneously may not equal the efficiency with which each receiver device receives power sequentially. Additionally, an off receiver device may have to store power for an extended period of time until its next on cycle, thus requiring a larger/more expensive charge storage device.

Exemplary embodiments of the present invention are directed to hybrid technology. In an exemplary embodiment of the invention, many receiver devices share a wireless charging area. Initially, they may all share receiving power at the same time. After a certain time, the control system (which includes feedback from the receiver devices) takes note of the amount of power actually received by each receiver device and, if necessary, via time division multiplexing methods, power level adjustment methods or a combination thereof to adjust power. Under most conditions, each receiver device will receive power most of the time. At some point in time, some receiver devices may be switched off or disabled from receiving power to reduce the total power they receive. For example, a receiver device placed on the transmit coil so that it receives most of the power may be switched off part of the time so that other receiver devices receive more power. As a result, imbalances due to placement of various receiver devices can be corrected. Another example might be two receiver devices placed so that they both share power and are initially both on 100% of the time. As one device finishes charging its battery, it may start shutting itself down an increasing percentage of the time to allow more power to reach the other device. Alternatively, the transmitter may start allocating smaller and smaller time slots to almost fully charged receiver devices to allow more power to reach other receiver devices.

13A-13C illustrate host device 150 having transmit antenna 204 and including receiver devices ( Dev1 and Dev2 ) placed in various positions relative to transmit antenna 204 . For simplicity, only two receiver devices are discussed herein, but the use of multiple devices is also contemplated to be within the scope of the teachings of the present invention and modifications to these will be apparent to those of ordinary skill in the art.

13A illustrates a situation where two receiver devices ( Dev1 and Dev2 ) are positioned to receive substantially equal amounts of power from transmit antenna 204 , eg, by approximately the same distance away from the perimeter of transmit antenna 204 . In FIG. 13A , both receiver devices Dev1 and Dev2 are placed near the center of the transmit antenna 204 .

In FIG. 13B , receiver devices Dev1 and Dev2 are placed away from each other but about the same distance from the perimeter of transmit antenna 204 . Accordingly, receiver devices Dev1 and Dev2 do not have to be close to each other or in the same geographic location within a power supply zone to receive the same amount of power from transmit antenna 204 . It should be noted that due to the varying coupling efficiency associated with the distance of the devices from the transmitter, in the FIG. 13A setup, receiver devices Dev1 and Dev2 may receive less power from the transmit antenna 204 (compared to compared to the power received). However, in each setup, the amount of power received in each of the devices is substantially equal to the amount of power received in the other device.

FIG. 13C illustrates a situation where receiver devices Dev1 and Dev2 are positioned to receive unequal amounts of power from transmit antenna 204 . In this example, receiver device Dev1 is placed near the center of transmit antenna 204 and will likely receive less power than receiver device Dev2 (receiver device Dev2 is placed closer to transmit antenna 204). In this case, Dev2 will charge faster than Dev1 and thus become fully charged earlier than Dev1.

14A-14G are simplified timing diagrams illustrating adaptive power control for delivering power to multiple receiver devices. For simplicity, only two devices are discussed herein, but the use of multiple devices is contemplated within the scope of the teachings of the present invention and modifications to these will be apparent to those of ordinary skill in the art.

In FIG. 14A , the Situation 0 scenario shows a timeline 700 illustrating a situation when a single receiver device is placed within the powering area of the transmitter antenna 204 . In this case, a single receiver device receives substantially all of the power provided by transmit antenna 204 during each recursion period 610 . As discussed above with reference to Figures 12A and 12B, a portion 620 of the recursion period 610 may be spent on optional signaling.

In FIG. 14B , the Case 1 scenario shows a timeline 711 for receiver device Dev1 and a timeline 712 for receiver device Dev2. In this case, each receiver device Dev1 and Dev2 consumes approximately 50% of the power supplied by the transmit antenna 204 . Case 14B is likely when two receiver devices are positioned symmetrically within the powering area of transmit antenna 204 (eg, in FIGS. 13A and 13B ). Accordingly, each of receiver devices Dev1 and Dev2 receives an equal amount of power (eg, receives 50% of the power, as shown by the vertical axis) during recursion period 610 . The signaling period 620 may also be used to allow communication between the transmitter and receiver and may reduce the charging time available for both devices.

In Figure 14C, the Situation 2 case (illustrated by timelines 721 and 722) uses time multiplexing. Accordingly, each of receiver devices Dev1 and Dev2 receives an equal amount of power during the recursion period 610 . However, in Case 2, Dev1 is enabled to receive 100% power for 50% of the recursive period 610 and Dev2 is enabled to receive 100% power for the other 50% of the recursive period 610 . The signaling period 620 may also be used to allow communication between the transmitter and receiver and may reduce the charging time available for both devices.

In FIG. 14D , Case 3 scenarios illustrate timelines 731 and 732 , where during signaling period 610 two receiver devices Dev1 and Dev2 may be enabled to receive power. Even though signaling may occur, receiver devices Dev1 and Dev2 can still draw power from the signal. Thus, in Case 3, each of the receiving devices is enabled to receive power during the signaling period 620 and thus receives approximately 50% of the power during the signaling period 620 . The power portion of recursion cycle 610 (ie, the portion of recursion cycle 610 not used by signaling cycle 620 ) may be split equally for time division multiplexing between receiver device Dev1 and receiver device Dev2.

In FIG. 14E , the Case 4 scenario shows a timeline 741 for receiver device Dev1 and a timeline 742 for receiver device Dev2. In Case 4, receiver devices Dev1 and Dev2 are positioned to receive unequal amounts of power from transmit antenna 204, e.g., receiver device Dev1 is placed near the center of transmit antenna 204 and receives less power than receiver device Dev2 (receiver device Dev2). Dev2 is placed closer to the transmit antenna 204) (as shown in Figure 13C) less power. Each of receiver devices Dev1 and Dev2 relies on its coupling to transmit antenna 204 to distribute power between the two devices in the power zone. Thus, in Scenario 4, the better positioned receiver device (e.g., receiver device Dev2) receives about 75% of the power, while receiver device Dev1 receives the other 25% of the power, since the power division is purely by The location of the antenna 204 is determined suboptimally.

In FIG. 14F , the Case 5 scenario shows a timeline 751 for receiver device Dev1 and a timeline 752 for receiver device Dev2. In Case 5, receiver devices Devl and Dev2 are positioned to receive unequal amounts of power from the transmit antennas in a manner similar to that of Figure 14E. However, while each receiver device relies in part on its relative coupling to transmit antenna 204 to distribute power, each receiver device may also decouple itself from transmit antenna 204 when desired. If a 50/50 power split is desired, the receiver device Dev2 itself may be disabled from receiving power during the P2 portion of the recursive cycle 610, while Dev1 remains enabled to receive 100% power during the P1 portion.

During the P1 portion and the signaling portion 620, both receiver devices remain on such that receiver device Dev1 receives about 25% of the power and receiver device Dev2 receives about 75% of the power. The lengths of the P1 and P2 portions can be adjusted so that approximately 50% of the power (or other split ratios if desired) is allocated to each receiver device Dev1 and Dev2. Condition 5 is similar to Condition 2, but requires less disconnection time. For example, in Case 5, the receiving device Devl never becomes disabled from receiving power and only receives more power during portion P2 (due to receiver device Dev2 being disabled).

In FIG. 14G , the Case 6 scenario shows a timeline 761 for receiver device Dev1 and a timeline 762 for receiver device Dev2. Recalling the discussion above with respect to FIGS. 7-10 , the power output of transmit antenna 204 may be adjusted. Thus, in Figure 14G, the power output is shown in terms of wattage rather than in terms of percentage of full power. In Case 6, receiver devices Dev1 and Dev2 are positioned to receive approximately equal amounts of power from transmit antenna 204 . Thus, during signaling period 620, the transmitter may be set to deliver approximately 4 watts, and each of receiver devices Dev1 and Dev2 may receive approximately 2 watts. During the P1 portion, the receiver device Dev1 is disabled from receiving power and the power output of the transmit antenna is set to about 3 watts, which is mainly consumed by the receiver device Dev2. During part P2, receiver device Dev2 is disabled from receiving power and the power output of the transmit antenna is set to about 4 watts, which is mainly consumed by receiver device Dev1.

Figures 14A to 14G are given as examples of some possible situations. Those of ordinary skill in the art will recognize that many other situations involving more receiver devices and various power output levels are contemplated to be within the scope of the present invention.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and codes that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof. piece.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the exemplary embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the exemplary embodiments of the present invention.

The various illustrative logic blocks, modules, and circuits described in connection with the exemplary embodiments disclosed herein may be implemented with general purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), ) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, eg, a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of the methods or algorithms described in conjunction with the exemplary embodiments disclosed herein may be directly embodied in hardware, in software modules executed by a processor, or in a combination of the two. Software modules can reside in random access memory (RAM), flash memory, read only memory (ROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral with the processor. The processor and storage medium can reside in the ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and storage medium may reside as discrete components in the user terminal.

In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media (communication media includes any medium that facilitates transfer of a computer program from one place to another). Storage media may be any available media that can be accessed by a computer. By way of example and not limitation, such computer readable media may comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage, or may be used to carry or store desired program code and any other medium that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, Fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave are included in the definition of media. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and blu-ray disc where disks usually reproduce data magnetically, while discs usually reproduce data magnetically. Data is reproduced optically by laser light. Combinations of the above should also be included within the scope of computer-readable media.

The previous description of the disclosed exemplary embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these exemplary embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. . Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (43)

1. wireless power reflector, it comprises:

Transmitting antenna, it is used to produce the coupled mode district of the near-field thermal radiation that is used to be coupled to the reception antenna on a plurality of acceptor devices; And

Controller, it operationally is coupled to described transmitting antenna, wherein said controller:

Determine in recursion period at the one or more distributing electric power in the described a plurality of acceptor devices that are placed in the described coupled mode district; And

Adjust the power level of described near-field thermal radiation in response to the electric power requirement of at least one reception from described a plurality of acceptor devices.

2. wireless power reflector according to claim 1, it further comprises:

Amplifier, it is used for radio frequency (RF) signal is applied to described transmitting antenna; And

The power amplifier adjuster, it operationally is coupled to described amplifier and described controller; And

Wherein said controller is further:

Define a plurality of distributing electric power cycle during described recursion period, each distributing electric power cycle is used for one or more specific acceptor devices of described a plurality of acceptor devices; And

Control described power amplifier adjuster in described a plurality of distributing electric powers at least one in cycle, the power level of described amplifier be set to first power level and in described a plurality of distributing electric powers other assignment period in the cycle, the power level of described amplifier be set to second power level.

3. wireless power reflector according to claim 2, wherein said power amplifier adjuster comprises and has potentiometric buck-converter, and described buck-converter operationally is coupled to described controller to be used to adjust the power level of described amplifier.

4. wireless power reflector according to claim 2, wherein said power amplifier adjuster comprises buck-converter, and described controller further is configured to the power level of described amplifier is taken a sample and adjusted the electric power output of described buck-converter in response to the power level of described sampling.

5. wireless power reflector according to claim 2, wherein said controller determine that further described first power level is to share electric power between the more than one acceptor device in described a plurality of acceptor devices.

6. wireless power reflector according to claim 1, it further comprises:

Amplifier, it is used for radio frequency (RF) signal is applied to described transmitting antenna; And

Wherein said recursion period comprises the time multiplexing part, and described controller is further:

During the sync section of described recursion period, enable described amplifier so that described RF signal is applied to described transmitting antenna to produce described near-field thermal radiation; And

During the electric power radiating portion of described recursion period;

When existing in the described coupled mode district, continue the described described amplifier of enabling through specifying when accepting at least one acceptor device from the electric power of described near-field thermal radiation; And

When not existing in the described coupled mode district through specifying when accepting the acceptor device from the electric power of described near-field thermal radiation, the described amplifier of stopping using makes it described RF signal can not be applied to described transmitting antenna.

7. wireless power reflector according to claim 1, wherein said controller are further adjusted the described power level of described near-field thermal radiation in response to the power request level of the reception of the acceptor device from described a plurality of acceptor devices.

8. wireless power reflector according to claim 7, it further comprises the amplifier that is used for the RF signal is applied to described transmitting antenna, and the voltage designator that further receives in response to the acceptor device from described a plurality of acceptor devices of wherein said controller and adjust the described power level of described near-field thermal radiation by the voltage level that described amplifier is gone in adjustment.

9. wireless power reflector according to claim 7, it further comprises the amplifier that is used for the RF signal is applied to described transmitting antenna, and the electric current designator that further receives in response to the acceptor device from described a plurality of acceptor devices of wherein said controller and adjust the described power level of described near-field thermal radiation by the current level that described amplifier is gone in adjustment.

10. wireless power reflector according to claim 1, it further comprises:

Amplifier, it is used for radio frequency (RF) signal is applied to described transmitting antenna; And

The load sensing circuit, it operationally is coupled to described amplifier and described controller, described load sensing circuit is used to the continuous response signal that detects the change of the power consumption that is caused by described amplifier and produce described controller, the described change of described continuous response signal indication power consumption; And

Wherein said controller be further used for decoding described continuous response with determine in the described coupled mode district new acceptor device exist or described coupled mode district in the receiver information of existing acceptor device at least one.

11. wireless power reflector according to claim 1, wherein said controller further is communicated to described one or more acceptor devices in described a plurality of acceptor device during the signaling moiety of described recursion period, make it can not receive a part from the electric power of described near-field thermal radiation with the described acceptor device of should stopping using of indicating described recursion period.

12. a wireless power reflector, it comprises:

Transmitting antenna, it is used to produce the coupled mode district of the near-field thermal radiation that is used to be coupled to the reception antenna on a plurality of acceptor devices;

Controller, it operationally is coupled to described transmitting antenna, wherein said controller:

By receiving the coupling ratio that emission is determined to one or more acceptor devices in the described coupled mode district, the electric power amount that described emission indication receives from described acceptor device;

When always launch electric power and definite radiation electric power that is not received in response to the described coupling of each acceptor device by any acceptor device in the described coupled mode district; And

When being higher than predetermined threshold, described radiation electric power adjusts the power level of described near-field thermal radiation.

13. the method that wireless power transmits, it comprises:

Transmitting antenna by reflector is created in the electromagnetic field under the resonance frequency, to produce the coupled mode district in the near field of described transmitting antenna;

During the sync section of recursion period, define the beginning of described recursion period by the described electromagnetic field of ON/OFF keying; And

During the electric power radiating portion of described recursion period;

Described electromagnetic field couples is arrived the reception antenna of first acceptor device in the described coupled mode district; And

Described electromagnetic field couples is arrived the reception antenna of second acceptor device in the described coupled mode district.

14. method according to claim 13, it further comprises by adjusting emission electric power from described transmitting antenna, adjusting for the time quantum of each acceptor device emission electric power or its and make up the electric power amount that is delivered to each acceptor device of adjusting.

15. method according to claim 13, wherein:

The first of described electromagnetic field is coupled to the described reception antenna of described second acceptor device;

The second portion of described electromagnetic field is coupled to the described reception antenna of described second acceptor device; And

Described first and described second portion are in response to the placement with respect to described transmitting antenna of described first acceptor device and described second acceptor device.

16. method according to claim 13, it further comprises:

Determine when to exist in the described coupled mode district through specifying to accept a plurality of receivers from the electric power of described electromagnetic field;

The time multiplexing section of described electric power radiating portion is distributed to through specifying with in described a plurality of receivers of accepting electric power each; And

During described sync section, pass on each the described time multiplexing section distribute in described a plurality of receiver.

17. method according to claim 13, it further comprises:

Determine each the coupling ratio in described first acceptor device and described second acceptor device, described coupling ratio indication is from the part that is consumed by each acceptor device of the electric power in described coupled mode district; And

In response in described first acceptor device and described second acceptor device at least one described coupling ratio and distribute the time multiplexing section of described electric power radiating portion.

18. method according to claim 13, it further is included in two different time multiplexing sections of described electric power radiating portion the electric power output level of described transmitting antenna is adjusted at least two varying levels at least.

19. method according to claim 18 is wherein adjusted described electric power output level and comprised the voltage that amplifier is gone in adjustment, described amplifier operationally is coupled to described transmitting antenna.

20. method according to claim 18 is wherein adjusted described electric power output level and comprised the electric current that amplifier is gone in adjustment, described amplifier operationally is coupled to described transmitting antenna.

21. method according to claim 18 is wherein adjusted described electric power output level and is in response to from the power request level of described first acceptor device, described second acceptor device or its combined reception.

22. a power transmission system, it comprises:

Be used for transmitting antenna by reflector and be created in electromagnetic field under the resonance frequency in the near field of described transmitting antenna, to produce the device in coupled mode district;

Be used for during the sync section of recursion period, defining the device of the beginning of described recursion period by the described electromagnetic field of ON/OFF keying; And

During the electric power radiating portion of described recursion period;

Be used for described electromagnetic field couples is arrived the device of the reception antenna of first acceptor device in the described coupled mode district; And

Be used for described electromagnetic field couples is arrived the device of the reception antenna of second acceptor device in the described coupled mode district.

23. power transmission system according to claim 22, it further comprises and is used for by adjusting emission electric power from described transmitting antenna, adjusting for the time quantum of each acceptor device emission electric power or its and make up the device of adjusting the electric power amount that is delivered to each acceptor device.

24. power transmission system according to claim 22, wherein:

The described reception antenna of described second acceptor device is coupled in the first of described electromagnetic field;

The second portion of described electromagnetic field is coupled to the described reception antenna of described second acceptor device; And

Wherein said first and described second portion are in response to the placement with respect to described transmitting antenna of described first acceptor device and described second acceptor device.

25. power transmission system according to claim 22, it further comprises:

Be used for determining when existing in the described coupled mode district through specifying with the device of acceptance from a plurality of receivers of the electric power of described electromagnetic field;

Be used for the time multiplexing section of described electric power radiating portion is distributed to through specifying the device with each of described a plurality of receivers of accepting electric power; And

Be used for during described sync section passing on each the device of described time multiplexing section of distributing to described a plurality of receivers.

26. power transmission system according to claim 22, it further comprises:

Be used for determining each the device of coupling ratio of described first acceptor device and described second acceptor device, described coupling ratio indication is from the part that is consumed by each acceptor device of the electric power in described coupled mode district; And

Be used in response to described first acceptor device and described second acceptor device at least one described coupling ratio and distribute the device of the time multiplexing section of described electric power radiating portion.

27. power transmission system according to claim 22, it further comprises the device that is used at least two of described electric power radiating portion different time multiplexing sections the electric power output level of described transmitting antenna being adjusted at least two varying levels.

28. power transmission system according to claim 27, the wherein said device that is used to adjust described electric power output level comprises the device that is used to adjust the voltage of going to amplifier, and described amplifier operationally is coupled to described transmitting antenna.

29. power transmission system according to claim 27, the wherein said device that is used to adjust described electric power output level comprises the device that is used to adjust the electric current of going to amplifier, and described amplifier operationally is coupled to described transmitting antenna.

30. power transmission system according to claim 27, the wherein said device that is used to adjust described electric power output level is in response to from the power request level of described first acceptor device, described second acceptor device or its combined reception.

31. a wireless power receiver, it comprises:

Reception antenna, itself and coupled mode district coupling from the near-field thermal radiation of transmitting antenna;

Radio frequency (RF)/direct current (DC) transducer, it operationally is coupled to described reception antenna to be used for converting the near-field thermal radiation of described coupling to the DC signal;

The DC/DC transducer, it operationally is coupled to described RF/DC transducer to be used for that described DC conversion of signals is become output signal; And

Processor, it operationally is coupled to described reception antenna, described RF/DC transducer and described DC/DC transducer, wherein said processor:

Definite power level of wanting that operationally is coupled to the acceptor device of described output signal; And

Control described DC/DC transducer the power level on the described output signal is adjusted to the described power level of being wanted.

32. wireless power receiver according to claim 31, wherein said processor further the described DC/DC transducer of control with in response to described acceptor device the voltage level of being wanted and adjust described power level on the described output signal by the voltage level of adjusting described output signal.

33. wireless power receiver according to claim 31, wherein said processor further the described DC/DC transducer of control with in response to described acceptor device the current level of being wanted and adjust described power level on the described output signal by the current level of adjusting described output signal.

34. wireless power receiver according to claim 31, it further comprises:

Commutation circuit, it operationally is coupled between described reception antenna and the described RF/DC transducer, to be used to adjust by described transmitting antenna via the load of perception with the described coupling in described coupled mode district; And

Wherein said processor is further used for by communicating by letter with the emitter that operationally is coupled to described transmitting antenna via producing continuous signal on the described reception antenna of being controlled at of described commutation circuit.

35. wireless power receiver according to claim 34, the wherein said power level of wanting is to be communicated to described emitter by the described control of described processor by described commutation circuit.

36. wireless power receiver according to claim 35, the described power level of wanting that wherein is communicated to described emitter comprises the current level of wanting.

37. wireless power receiver according to claim 35, the described power level of wanting that wherein is communicated to described emitter comprises the voltage level of wanting.

38. a method that is used for the multiple arrangement wireless charging, it comprises:

Reception is from the electric power requirement of described multiple arrangement; And

In conjunction with not covering each device to be charged and cover the device that does not receive charging to come sequentially the device in the described multiple arrangement to be charged.

39. according to the described method of claim 38, wherein receiving the electric power requirement is in conjunction with taking place via ON/OFF keying received signal.

40. according to the described method of claim 38, it further comprises supervision and is delivered to the power level of described multiple arrangement and changes charge parameter in response to described power level.

41. according to the described method of claim 40, wherein said charge parameter comprises for delivery to the electric current of described multiple arrangement and voltage level.

42., wherein use near field wireless charging method to realize described wireless charging according to the described method of claim 38.

43. a wireless charger, it comprises:

Receiver, it is used for wirelessly receiving the electric power requirement from device to be charged;

The power components threshold dector; And

Processor, it can be operated with combination and monitor that the reading from described power components threshold dector changes the power components of armed signal so that satisfy described electric power requirement.

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