Enhanced Transmitter for Wireless Power Transmission

[0001] The present disclosure is related to U.S. non-provisional patent application DWV-3DPF-010 entitled “Methodology for Pocket-forming”; DWV-3DPF-015 entitled “Method for 3 Dimensional Pocket-forming”; DWV-3DPF-027 entitled “Receivers for Wireless Power Transmission”; DWV-3DPF-029 entitled “Transmitters for Wireless Power Transmission” invented by Michael A. Leabman; and ENG-SYHW-001 entitled “Enhanced Receiver for Wireless Power Transmission” invented by Jason Petras and Michael A. Leabman, each of which are incorporated by reference in their entireties.

[0002] 1. Field of the Disclosure

[0003] The present disclosure relates generally to wireless power transmission, and more specifically, to a transmitter apparatus which transmits wireless power at high power transmission efficiency to power or charge electronic devices.

[0004] 2. Background Information

[0005] A plurality of electronic devices are powered via rechargeable batteries. Such devices include smartphones, portable gaming devices, tablet computers, portable music players, laptop computers, computer peripheral devices, communication devices (e.g., Bluetooth devices), digital cameras, and hearing aids, amongst others. While battery technology has improved, battery-powered electronic devices increasingly require and consume greater amounts of power, thereby often requiring recharging. Rechargeable devices are often charged via wired connections through cables or other similar connectors that are physically connected to a power supply.

[0006] Wireless charging technology has been developed and used for electronic devices in an effort to solve problems presented by wired charging solutions, such as contamination of contact terminals and moisture preventing the appropriate charging of the battery in the electronic device. Wireless charging systems may be capable of transferring power in free space and provide power to electronic devices or can be used to charge rechargeable electronic devices. Wireless power transmission is performed through a transmitter and a receiver coupled to the electronic device to be charged. The receive antenna collects power from the transmitter and rectifies it for charging the battery.

[0007] Wireless power transmission (WPT) using radio frequency (RF) waves has been enabled in a plurality of applications, such as power transmission from space to earth and microwave-powered aircraft; powering of devices using an inductive resonance coupling scheme that makes use of near-field coupling between two magnetic resonators; and development of antenna arrays to harvest very low power levels from an RF transmitter located within a very short distance; amongst other applications.

[0008] During WPT using RF waves, power losses occur due to factors, such as RF-to-direct-current (RF-DC) conversion, hardware configuration and control logic for transmission, and RF propagation, amongst others. Recent developments have reduced losses from RF-DC conversion and spatial beam-forming improving the RF propagation efficiency.

[0009] Notwithstanding developments in current art, there is still a gap between existing technologies and practical WPT. Specifically, reliability in charging portable devices in complex environments of everyday life, efficient wireless power transmission, safety assurance, and cost, size and weight reduction of components for a wireless power transmission system.

[0010] As such, there is a need for a wireless power transmitter which addresses the previously mentioned limitations and more particularly, capable of transmitting wireless power with hardware components of lower cost and compactness which can provide high power efficiency.

[0011] An enhanced transmitter apparatus for transmitting wireless power or voltage from a plurality of received radio frequency (RF) signals is disclosed. The transmitter may deliver wireless power or voltage to a receiver apparatus which may extract and convert the transmitted RF waves in power or voltage for charging or powering an electronic device.

[0012] According to embodiments, it is an object of the present disclosure to provide an enhanced design for wireless power transmission transmitters of a discrete and low-cost system configuration and a plurality of power transfer control schemes for enhanced power efficiency transmission of a plurality of received RF waves to be transmitted to a wireless receiver.

[0013] The enhanced wireless power transmitter may be designed in accordance with a plurality of transmitter arrangements which may be employed for wireless transmission using suitable power transmission techniques. In present disclosure, suitable power transmission technique may preferably be the pocket-forming power transmission technique.

[0014] Accordingly, in an embodiment, a transmitter including a plurality of antenna elements may generate RF signals using a plurality of radio frequency integrated circuit (RFIC) which may be driven by one or more microcontrollers or digital signal processor (DSP) controllers. Wireless transmitters may receive power from a power source, which may provide power levels required for transmission of RF signals to the wireless receiver, which may be integrated in the electronic device.

[0015] In an another aspect of present disclosure, wireless power transmission may be enabled with a plurality of transmission configurations and/or sets of the antenna elements and RFICs which may be employed depending on the location from which wireless RF signals may be received and the position of the wireless receiver in the electronic device to be powered or charged. A proprietary algorithm residing in a micro-controller may control the operation of a set/configuration of dedicated antenna elements and a receiving (Rx) RFIC, which may be specifically designed for reception of RF input signals and which may include a plurality of hardware components for sampling and down-converting the received RF input signals to be transmitted to a wireless power receiver. Additionally, same micro-controller may control a set of transmitting (Tx) RFICs of different design and components as those used in the Rx RFIC, as well as a plurality of antenna elements for the transmission of wireless power RF signals to the wireless receiver in a faster manner, thus enhancing the power transmission efficiency.

[0016] In yet another aspect, the single Rx RFIC may be designed to provide the proper down-conversion and processing/sampling of received RF signals for the DSP controller to enable the mode of transmission configuration with the appropriate set of Tx RFICs and antenna elements, using a reduced instruction set computing architecture of an ARM micro-processor in the micro-controller. The enhanced wireless power transmitter may provide a faster way of receiving/transmitting signals at same or higher frequency level as the frequency of RF input signals. The DSP or micro-controller in the enhanced wireless power transmitter may update control signals for the dedicated Rx RFIC up to 1,000 times/sec depending on duration of received signals, which may be as fast as 10 μsec.

[0017] The use of an ARM micro-processor may reduce cost, heat and power use, as it may be desirable for electronic devices to be powered or charged using wireless power transmission. The instruction set architecture of the ARM micro-processor may allow higher processing power and energy efficiency for the micro-controller in the enhanced wireless power transmitter.

[0018] Notwithstanding developments, the enhanced wireless power transmitter of present disclosure may address the existing gap between current technologies and practical wireless power transmission, specifically, in reliability in powering or charging portable devices in complex environments, efficient wireless power transmission, safety assurance, and cost, size and weight reduction of components for a wireless power transmission system.

[0019] Numerous other aspects, features and benefits of the present disclosure may be made apparent from the following detailed description taken together with the drawing figures.

[0026] The present disclosure is here described in detail with reference to embodiments illustrated in the drawings, which form a part here. Other embodiments may be used and/or other changes may be made without departing from the spirit or scope of the present disclosure. The illustrative embodiments described in the detailed description are not meant to be limiting of the subject matter presented here.

[0027] As used here, the following terms may have the following definitions:

[0028] “Wireless device” refers to any electronic device able to communicate using one or more suitable wireless technologies. Suitable devices may include client devices in wireless networks and may be part of one or more suitable wireless technologies, including Wi-Fi and Bluetooth, amongst others.

[0029] “Wireless transmitter” refers to a device, including a chip which may generate two or more RF signals, at least one RF signal being phase shifted and gain adjusted with respect to other RF signals substantially, all of which pass through one or more RF antenna such that focused RF signals are directed to a target.

[0030] “Wireless receiver” refers to a device including at least one antenna element, at least one rectifying circuit and at least one power converter, which may utilize pockets of energy for powering, or charging a wireless device.

[0031] “Pocket-forming” may refer to generating two or more RF waves which converge in 3-d space, forming controlled constructive and destructive interference patterns.

[0032] “Adaptive pocket-forming” may refer to dynamically adjusting pocket-forming to regulate power on one or more targeted receivers.

[0033] An enhanced transmitter apparatus for transmitting wireless power or voltage from a plurality of received radio frequency (RF) signals is disclosed. The transmitter may deliver wireless power or voltage to a receiver apparatus which may extract and convert the transmitted RF waves in power or voltage for charging or powering an electronic device.

[0034] FIG. 1 illustrates a wireless power transmission 100 using pocket-forming. A transmitter 102 may transmit controlled Radio Frequency (RF) waves 104 which may converge in 3-d space. These RF waves 104 may be controlled through phase and/or relative amplitude adjustments to form constructive and destructive interference patterns (pocket-forming). Pockets of energy 106 may be formed at constructive interference patterns and can be 3-dimensional in shape, while null-spaces may be generated at destructive interference patterns. A receiver 108 may then utilize pockets of energy 106 produced by pocket-forming for charging or powering a cordless electronic device 110, for example, a smartphone, a tablet, a laptop computer (as shown in FIG. 1), a music player, an electronic toy, and the like. In some embodiments, there can be multiple transmitters 102 and/or multiple receivers 108 for powering various electronic devices 110 at the same time. In other embodiments, adaptive pocket-forming may be used to regulate the power transmitted to electronic devices 110.

[0035] FIG. 2 depicts the block diagram of receiver 108 which can be used for wireless powering or charging one or more electronic devices 110 as exemplified in wireless power transmission 100. According to some aspects of this embodiment, receiver 108 may operate with the variable power source generated from transmitted RF waves 104 to deliver constant and stable power or energy to electronic device 110. In addition, receiver 108 may use the variable power source generated from RF waves 104 to power up electronic components within receiver 108 for proper operation.

[0036] Receiver 108 may include a housing 202 where at least one antenna element 204, one rectifier 206, one power converter 208 and a communications component 210 may be included. Housing 202 can be made of any suitable material which may allow for signal or wave transmission and/or reception, for example plastic or hard rubber. Housing 202 may be an external hardware that may be added to different electronic equipment, for example in the form of cases, or may be embedded within electronic equipment as well. Antenna element 204 may include suitable antenna types for operating in frequency bands similar to the bands for transmitter 102 from FIG. 1.

[0037] Antenna element 204 may include vertical or horizontal polarization, right hand or left hand polarization, elliptical polarization, or other suitable polarizations, as well as suitable polarization combinations. Using multiple polarizations may be beneficial in devices where there may not be a preferred orientation during usage or whose orientation may vary continuously through time, for example a smartphone or portable gaming system. On the contrary, for devices with well-defined orientations, for example a two-handed video game controller, there might be a preferred polarization for antennas which may dictate a ratio for the number of antennas of a given polarization. Suitable antenna types may include patch antennas with heights from about 1/24 inches to about 1 inch and widths from about 1/24 inches to about 1 inch. Patch antennas may have the advantage that polarization may depend on connectivity, i.e., depending on which side the patch may be fed, the polarization may change. This may further prove advantageous as a receiver, such as receiver 108, may dynamically modify its antenna polarization to optimize wireless power transmission.

[0038] Rectifier 206 may include diodes or resistors, inductors or capacitors to rectify the alternating current (AC) voltage generated by antenna element 204 to direct current (DC) voltage. Rectifier 206 may be placed as close as is technically possible to antenna element 204 to minimize losses. After rectifying AC voltage, DC voltage may be regulated using power converter 208. Power converter 208 can be a DC-DC converter which may help provide a constant voltage output, regardless of input, to an electronic device, or as in this embodiment to a battery 212. Typical voltage outputs can be from about 5 volts to about 10 volts. In some embodiments, power converter 208 may include electronic switched mode DC-DC converters which can provide high efficiency. In such a case, a capacitor (not shown) may be included before power converter 208 to ensure that sufficient current is provided for the switching device to operate. When charging an electronic device 110, for example a phone or laptop computer, initial high currents, which can break-down the operation of an electronic switched mode DC-DC converter, may be required. In such a case, a capacitor (not shown) may be added at the output of receiver 108 to provide the extra energy required. Afterwards, lower power may be provided, for example 1/80 of the total initial power while still having the phone or laptop to build-up charge. Lastly, a communications component 210 may be included in receiver 108 to communicate with a transmitter or other electronic equipment.

[0039] Different antenna, rectifier or power converter arrangements may be possible for a receiver 108.

[0040] FIG. 3 depicts the block diagram of an enhanced wireless power transmitter 102 which may be used in wireless power transmission 100. Transmitter 102 may include a housing 302, at least two or more antenna elements 304, at least one receiving (Rx) RF integrated circuit (RFIC) 306, a plurality of transmitting (Tx) RF integrated circuit (RFIC) 308, at least one digital signal processor (DSP) or micro-controller 310, and one communications component 312. Micro-controller 310 may be included into an independent base station or into the transmitter 102.

[0041] RF input signals 314 may be produced using a power source 316 and a local oscillator chip (not shown) using a suitable piezoelectric material, or may be from other wireless sources (not shown), such as from a frequency chip, Bluetooth, and Wi-Fi.

[0042] Housing 302 may be made of any suitable material which may allow for signal or wave transmission and/or reception, for example plastic or hard rubber. Antenna elements 304 may include suitable antenna types for operating in frequency bands such as 900 MHz, 2.5 GHz or 5.8 GHz as these frequency bands conform to Federal Communications Commission (FCC) 47 CFR Part 18—Industrial, Scientific, and Medical Equipment. Antenna elements 304 may include vertical or horizontal polarization, right hand or left hand polarization, elliptical polarization, or other suitable polarizations as well as suitable polarization combinations. Suitable antenna types may include, for example, patch antennas with heights from about ⅛ of an inch to about 8 inches and widths from about ⅛ of an inch to about 6 inches. Other antenna elements 304 types that may be used include meta-materials based antennas, dipole antennas, and planar inverted-F antennas (PIFAs), amongst others.

[0043] Transmitter 102 may include a plurality of arrangements in which antenna elements 304 may be connected to dedicated Rx RFIC 306 or to Tx RFICs 308. Arrangements may include different configurations, such as a dedicated row or column of antenna elements 304 coupled to Rx RFIC 306, and at least two or more rows or columns of antenna elements 304 coupled to Tx RFICs 308. Rx RFIC 306 may include a proprietary chip for adjusting phases and/or relative magnitudes of frequency of RF input signals 314 collected from the dedicated set/configuration antenna elements 304 for reception of RF input signals 314. Rx RFIC 306 may be designed to include hardware and logic elements specifically dedicated for reception and processing of RF input signals 314, which are not included as components of TX RFICs 308.

[0044] In present embodiment of the enhanced wireless transmitter 102, 24 RFICs may be connected to 200 antenna elements 304 and configured to allow operation of Rx RFIC 306 as the dedicated receiver of RF input signals 314 operatively coupled to a dedicated column of at least two or more antenna elements 304, depending on the transmitter 102 configuration and operation, for example, eight antenna elements 304. The remaining 23 Tx RFICs 308 may be operatively coupled to a set/configuration of antenna elements 304, other than those used to receive RF input signals 314 by Rx RFIC 306. Tx RFICs 308 may be coupled to transmitting antenna elements 304 depending on control signals from micro-controller 310.

[0045] Micro-controller 310 may include a proprietary algorithm to implement control of Rx RFIC 306 and to allow operation of Rx RFIC 306 using a switching control which enables monitoring of reception separately from transmission without overlapping in the operation of Rx RFIC 306 and Tx RFICs 308. RF input signals 314 may be sampled at once after Rx RFIC 306 may be allowed to receive by switching control in micro-controller 310.

[0046] After the operation of Rx RFIC 306, Tx RFICs 308 may implement wireless power transmission 100 to receiver 108. Micro-controller 310 may select a column of antenna elements 304, a row of antenna elements 304, or any interpolation of arrangement of antenna elements 304 to couple with Tx RFICs 308, depending on location from which wireless power is to be transmitted.

[0047] Micro-controller 310 may also process information sent by receiver 108 through communications component 312 for determining optimum times and locations for pocket-forming. Communications component 312 may be based on standard wireless communication protocols which may include Bluetooth, Wi-Fi or ZigBee. In addition, communications component 312 may be used to transfer other information, such as an identifier for the device or user, battery level, location, or other such information. Other communications component 312 may be possible, including radar, infrared cameras or sound devices for sonic triangulation of electronic device 110 position.

[0048] FIG. 4 represents a transmitter arrangement 400 of antenna elements 304 which may be coupled to dedicated Rx RFICs 306, according to an embodiment.

[0049] Depending on the location from which RF input signals 314 may be received and information sent by receiver 108 to be processed by communications component 312 regarding determination of optimum times and locations for pocket-forming, which may enhance efficiency of wireless power transmission 100, micro-controller 310 may select Tx RFICs 308 and the arrangement of antenna elements 304 to maximize the transmission operation of transmitter 102. As seen in FIG. 4, micro-controller 310 may send switching control signals to Rx RFIC 306 coupled to either antenna column 402 or antenna row 404 to include the antenna elements 304 receiving RF input signals 314, as described in FIG. 3. After reception and processing of signals by Rx RFIC 306, the remaining antenna elements 304 may be coupled to Tx RFICs 308 using a plurality of configurations of antenna elements 304 as a result of an interpolation step which may be performed by micro-controller 310 to control operation of Tx RFICs 308 using the ARM micro-processor in micro-controller 310 to enhance wireless power transmission performance of transmitter 102, directing transmission of wireless power to the appropriate location.

[0050] Antenna elements 304 to connected to Rx RFIC 306 may reduce processing requirement and may increase control over pocket-forming, allowing multiple pocket-forming and a higher granular pocket-forming with less load over micro-controller 310; thus, a higher response of higher number of multiple pocket-forming may be allowed for transmission. Furthermore, multiple pocket-forming may charge a higher number of receivers 108 and may allow a better trajectory to such receivers 108 to provide a less expensive embodiment.

[0051] FIG. 5 illustrates a block diagram 500 of Rx RFIC 306 in an enhanced wireless power transmitter 102, according to an embodiment.

[0052] RF input signals 314 received by antenna elements 304 dedicated for reception and operatively coupled to Rx RFIC 306, depending on the location from which they may be radiated to transmitter 102, enable micro-controller 310, as described in FIG. 4. RF input signal 314 may then be subject to frequency sampling by an array of down-converters 502 included in Rx RFIC 306 in which the range of frequencies of RF input signals 314 of about 2.4 GHz or about 5.6 GHz may be shifted into RF signals of a new frequency range.

[0053] Down-converters 502 may include a local oscillator (not shown) providing a signal of pre-determined frequency to mix with the RF input signals 314 creating a sum heterodyne and a difference heterodyne from which one of the heterodyne may be filtered to provide the desired output frequency. In present embodiment a signal of about 5.8 GHz may be down-converted to an output signal of about 5.0 GHz. Output signal of 5.0 GHz from down-converters 502 may then be fed to addressing lines (A20) 504 at 10 MHz for processing by micro-controller 310. Enhanced wireless power transmitter 102 may be receiving at one frequency, for example 2.4 GHz, and transmitting at a higher frequency, for example 5.7 GHz.

[0054] Micro-controller 310 may be enabled to send control signals of about 1 msec or about 100 μsec to Rx RFIC 306 and depending on how fast the RF input signals 314 may being received, control may be enabled every msec or about 10 times/sec for 1 msec. If RF input signals 314 may be constantly received, for example every 10 μsec, updating may be implemented to about 1,000 times/sec.

[0055] In micro-controller 310, the proprietary algorithm may enable sampling of the incoming signals from each A20 504 and may use an ARM micro-processor (not shown) to drive the required Tx RFICs 308 coupled to the determined set/configuration of antenna elements 304 to transmit wireless power to the appropriate location of receiver 108. The use of an ARM micro-processor may reduce cost, heat and power use, as it may be desirable for electronic devices 110 to be powered or charged using wireless power transmission 100. The instruction set architecture of the ARM micro-processor may allow higher processing power and energy efficiency for micro-controller 310.

[0056] While various aspects and embodiments have been disclosed, other aspects and embodiments may be contemplated. The various aspects and embodiments disclosed here are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.