Wireless field power transmission system and transmitter and method for wirelessly transmitting power

Abstract

A transmitting resonator is provided. The transmitting resonator includes: two inductors; a switch network electrically connected to the inductors; a plurality of capacitive electrodes electrically connected to the switch network; a detector communicatively connected to the capacitive electrodes; and a controller communicatively connected to the switch network and the detector. The detector is configured to detect impedance. The controller is configured to control the switch network to control which electrodes are connected to the inductor based on the detected impedance. The inductor and the electrode are configured to resonate to generate an electric field.

Description

Technical Field

[0001] The present application generally relates to wireless power transmission, and more particularly to a wireless field power transmission system, and a transmitter and a receiver thereof. Background Art

[0002] There are many known wireless power transfer systems. A typical wireless power transfer system includes a power source electrically connected to a wireless power transmitter and a wireless power receiver electrically connected to a load. In a magnetic induction system, the transmitter has an induction coil that transfers power from the power source to the induction coil of the receiver. Power transfer occurs due to the coupling of the magnetic field between the induction coil of the transmitter and the induction coil of the receiver. These magnetic induction systems have a limited range, and the induction coil of the transmitter and the induction coil of the receiver must be in optimal alignment for power transfer. There are also resonant magnetic systems, in which power is transferred due to the coupling of the magnetic field between the induction coil of the transmitter and the induction coil of the receiver. However, in a resonant magnetic system, at least one capacitor is required to resonate the induction coil. Compared to a magnetic induction system, the range of power transfer in a resonant magnetic system is increased, and alignment issues are corrected. Although electromagnetic energy can be generated in magnetic induction systems and resonant magnetic systems, most power transfer is via magnetic fields. Very little, if any, power is transferred via electric induction or resonant electric induction.

[0003] In an inductive system, the transmitter and receiver have capacitive electrodes. Power transfer occurs due to the coupling of the electric field between the capacitive electrodes of the transmitter and receiver. Similar to resonant magnetic systems, there are also resonant electric systems in which at least one inductor is used to resonate the capacitive electrodes of the transmitter and receiver. Resonant electric systems have a greater power transfer range than inductive systems and correct alignment issues. Although electromagnetic energy can be generated in both inductive and resonant electric systems, most power transfer occurs via electric fields. Very little, if any, power is transferred via magnetic induction or resonant magnetic induction.

[0004] Although wireless power transmission technology is known, there is still a need for improvement. Therefore, an object of the present invention is to provide a novel wireless field power transmission system and its transmitter and receiver, as well as a method for wirelessly transmitting power. Summary of the invention

[0005] It should be understood that this summary is provided to introduce in simplified form some concepts that will be further described in the detailed description below. This summary is not intended to be used to limit the scope of the subject matter protected by the claims.

[0006] Thus, in one aspect, a transmitting resonator is provided, comprising: at least two inductors; a switching network electrically connected to the inductors; a plurality of capacitive electrodes electrically connected to the switching network; a detector communicatively connected to the capacitive electrodes, the detector being configured to detect impedance; and a controller communicatively connected to the switching network and the detector, the controller being configured to control the switching network to control which electrodes are connected to the inductors based on the detected impedance, wherein the inductors and electrodes are configured to resonate to generate an electric field.

[0007] In one or more embodiments, the detector includes a first detector and a second detector.

[0008] In one or more embodiments, the first detector is configured to detect impedance presented to the electrode.

[0009] In one or more embodiments, the detector includes at least one circuit and a phase detector. In one or more embodiments, the circuit is configured to measure impedance by applying a voltage and detecting a current.

[0010] In one or more embodiments, the second detector is configured to detect impedance during the wireless power transfer.

[0011] In one or more embodiments, the switch network is configured to electrically connect each electrode to two inductors.

[0012] In one or more embodiments, the transmitting resonator has the same number of inductors as capacitive electrodes.

[0013] In one or more embodiments, the capacitive electrodes are electrically connected to the switch network. In one or more embodiments, the detector is electrically connected to the controller and / or the controller is electrically connected to the switch network.

[0014] In one or more embodiments, the inductor is a variable inductor. In one or more embodiments, the controller is electrically connected to the variable inductor, and wherein the controller is configured to control the inductance of the variable inductor. In one or more embodiments, the capacitor electrode is electrically connected to the switch network via the variable inductor.

[0015] In one or more embodiments, the inductor and the electrodes are configured to resonate to generate an electric field to transfer electrical energy via electric field coupling.

[0016] According to another aspect, there is provided a wireless power transmission system comprising any of the transmitting resonators described.

[0017] According to another aspect, a wireless power transmission system is provided, comprising: a transmitter, comprising: a power supply configured to generate a power signal; and a transmitting resonator electrically connected to the power supply, the transmitting resonator comprising: at least two transmitting inductors; a switching network electrically connected to the transmitting inductor; a plurality of transmitting capacitor electrodes electrically connected to the switching network; a detector communicatively connected to the transmitting capacitor electrodes, the detector being configured to detect impedance; and a controller communicatively connected to the switching network and the detector, the controller being configured to control the switching network to control which transmitting capacitor electrode is connected to the transmitting inductor based on the detected impedance, wherein the transmitting inductor and the transmitting capacitor electrode are configured to resonate to generate an electric field; and a receiver, comprising: a load; and a receiver resonator electrically connected to the load, the receiver resonator comprising: at least two receiving inductors; and at least two receiving capacitor electrodes electrically connected to the receiving inductor, wherein the receiving inductor and the receiving capacitor electrodes are configured to resonate in the generated electric field and extract power via resonant electric field coupling.

[0018] In one or more embodiments, the transmitter further includes an inverter electrically connected between the power supply and the transmit resonator.

[0019] In one or more embodiments, the receiver further includes a rectifier electrically connected between the load and the receiving resonator.

[0020] According to another aspect, a method for wireless power transmission is provided, the method comprising: detecting impedance at at least two capacitor electrodes electrically connected to a switch network; transmitting the impedance at the capacitor electrodes to a controller communicatively connected to the switch network; at the controller, determining a subset of the capacitor electrodes to connect to at least two inductors based on the impedance at the capacitor electrodes, the inductors being electrically connected to the switch network; connecting the subset of the capacitor electrodes to the inductors; and resonating the inductors and the subset of the capacitor electrodes to generate an electric field.

[0021] In one or more embodiments, connecting the subset of capacitor electrodes includes sending a signal from a controller to a switch network to connect the subset of capacitor electrodes to the inductor.

[0022] In one or more embodiments, the method further includes: detecting the impedance at the inductor; sending the impedance at the inductor to a controller; determining at the controller whether the impedance at the inductor is within an impedance range; and if the impedance at the inductor is not within the impedance range, sending a signal from the controller to a switching network to disconnect all capacitor electrodes from the inductor.

[0023] In one or more embodiments, the impedance range is the impedance at which electrical energy can be transferred from the capacitive electrodes and the inductor via resonant electrical coupling.

[0024] In one or more embodiments, the method further includes: resonating an inductor and a capacitor electrode of the receiver at a resonant frequency; and extracting electrical energy from the generated electric field via resonant electric field coupling. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Embodiments will now be described more fully with reference to the accompanying drawings, in which:

[0026] Figure 1 is a block diagram showing a wireless power transmission system;

[0027] Figure 2 is a schematic layout showing a wireless resonant electric field power transmission system;

[0028] Figure 3 is a schematic layout showing a transmitting resonator according to one aspect of the present disclosure;

[0029] Figure 4 It shows Figure 3 Schematic diagram of the capacitive electrodes of the transmitting resonator;

[0030] Figure 5 It shows Figure 3 Another schematic diagram of the capacitive electrodes of the transmitting resonator;

[0031] Figure 6 is a schematic layout showing another embodiment of a transmitting resonator according to one aspect of the present disclosure;

[0032] Figure 7 The schematic diagram of the wireless power transmission system includes Figure 6 The transmitting resonator;

[0033] Figure 8 is a plan view showing another embodiment of a partial wireless power transmission system, the partial wireless power transmission system comprising Figure 6 The transmitting resonator;

[0034] Fig. 9 is a plan view showing another embodiment of a partial wireless power transmission system, the partial wireless power transmission system comprising Figure 6 The transmitting resonator;

[0035] Fig.10 is a plan view showing another embodiment of a partial wireless power transmission system, the partial wireless power transmission system comprising Figure 6 The transmitting resonator;

[0036] Fig.11 It shows Figure 3 A plan view of another embodiment of a capacitive electrode and a passive electrode of a transmitting resonator;

[0037] Fig.12 It shows Figure 7 A schematic layout of another embodiment of a wireless power transmission system;

[0038] Fig.13 It shows Figure 7 A schematic layout of another embodiment of a wireless power transmission system;

[0039] Fig.14 It shows Figure 7 A schematic layout of another embodiment of a wireless power transmission system;

[0040] Fig.15 is a plan view showing another embodiment of a portion of a wireless power transfer system according to one aspect of the system;

[0041] Fig.16 is a plan view showing another embodiment of a portion of a wireless power transmission system;

[0042] Fig.17 It shows Fig.15 Diagram of the electric field of the wireless power transfer system;

[0043] Fig.18 It shows Fig.16 Diagram of the electric field of the wireless power transfer system;

[0044] Fig.19 It shows Figure 7 A schematic layout of another embodiment of a wireless power transmission system;

[0045] Fig. 20 It shows Fig.19 A graph of the radio frequency (RF) efficiency of a wireless power transfer system;

[0046] Fig.21 It shows Fig.19 A diagram of the input impedance of a wireless power transfer system;

[0047] Fig. 22 is a perspective view showing another embodiment of a portion of a wireless power transfer system according to one aspect of the system;

[0048] Fig.23 It shows Fig. 22 Another perspective view of the wireless power transmission system;

[0049] Fig.24 is a perspective view showing a portion of another embodiment of a wireless power transfer system; and

[0050] Fig.25 It shows Figure 22 to Figure 24A graph of the specific absorption rate (SAR) versus distance for a wireless power transfer system. DETAILED DESCRIPTION

[0051] The aforementioned summary of the invention and the following detailed description of certain embodiments will be better understood by reading in conjunction with the accompanying drawings. It should be understood that throughout the specification and the accompanying drawings, the same reference numerals are used to refer to the same elements. As used herein, the elements or features described in the singular and beginning with the word "one (kind)" should be understood to not necessarily exclude multiple elements or features. In addition, reference to "an example" or "an embodiment" is not intended to be interpreted as excluding the existence of additional examples or embodiments of the elements or features further combined with an example or an embodiment. In addition, unless the opposite meaning is clearly stated, "including", "having" or "comprising" an element or feature or multiple elements or features with a specific attribute or an example or embodiment can also include additional elements or features without a specific attribute. Similarly, it will be understood that the terms "including", "having" and "comprising" mean "including but not limited to", and the terms "including", "having" and "comprising" have equivalent meanings.

[0052] As used herein, the term "and / or" may include any and all combinations of one or more of the associated listed elements or features.

[0053] It should be understood that when an element or feature is referred to as being "on", "attached to", "connected to", "coupled to", "in contact with", etc., another element or feature, the element or feature may be directly on, attached to, connected to, coupled to, or in contact with another element or feature, or there may be intermediate elements. In contrast, when an element or feature is referred to as being, for example, "directly on", "directly attached to", "directly connected to", "directly coupled to", or "in direct contact with" another element or feature, there are no intermediate elements or features.

[0054] It should be understood that spatially relative terms, such as "below", "beneath", "lower", "above", "above", "upper", "front", "back", etc., may be used herein to facilitate describing the relationship of one element or feature to another element or feature shown in the figures. However, the spatially relative terms may also include different orientations in use or operation in addition to the orientations depicted in the figures.

[0055] References to "examples" herein mean that one or more features, structures, elements, components, characteristics, and / or operational steps described in conjunction with the examples are included in at least one embodiment and / or implementation of the subject matter according to the present disclosure. Therefore, phrases "an example," "another example," and similar language throughout the present disclosure may, but do not necessarily, refer to the same example. In addition, a subject matter having features of any one example may, but does not necessarily, include a subject matter having features of any other example.

[0056] The “configured” mentioned herein refers to an actual configuration state, which substantially relates an element or feature to the physical characteristics of the element or feature preceding the phrase “configured to”.

[0057] Unless otherwise indicated, the terms "first," "second," etc. are used herein merely as labels and are not intended to impose order, position, or hierarchical requirements on the items to which these terms refer. Furthermore, reference to a "second" item does not require or preclude the presence of lower-numbered items (e.g., the "first" item) and / or the presence of higher-numbered items (e.g., the "third" item).

[0058] As used herein, the terms "about" and "approximately" refer to an amount that is close to a stated amount and still performs a desired function or achieves a desired result. For example, the terms "about" and "approximately" may refer to an amount that is less than within 10%, less than within 5%, less than within 1%, less than within 0.1%, or less than within 0.01% of a stated amount.

[0059] Figure 1 A wireless power transfer system is shown and generally identified by reference numeral 100. The wireless power transfer system 100 includes a transmitter 110 including a power source 112 electrically connected to a transmit element 114 and a receiver 120 including a receive element 124 electrically connected to a load 122. Electrical power is transferred from the power source 112 to the transmit element 114. The electrical power is then transferred from the transmit element 114 to the receive element 124 via resonant or non-resonant electric or magnetic field coupling. The electrical power is then transferred from the receive element 124 to the load 122.

[0060] In one example embodiment, the wireless power transfer system may take the form of a resonant electric field wireless power transfer system. Figure 2 A resonant electric field wireless power transfer system is shown, generally identified by reference numeral 200, such as the system described in U.S. Patent No. 9,653,948 to Polu et al., filed September 7, 2012, the relevant portions of which are incorporated herein by reference.

[0061] The resonant electric field wireless power transfer system 200 includes a transmitter 210 including a power source 212 electrically connected to a transmit resonator 214. The transmit resonator 214 includes a pair of laterally spaced elongated transmit capacitor electrodes 216, each of which is electrically connected to the power source 212 via a high quality factor (Q) transmit inductor 218. The system 200 also includes a receiver 220 including a receiver resonator 224 electrically connected to a load 222. The receive resonator 224 is tuned to the resonant frequency of the transmit resonator 214. The receive resonator 224 includes a pair of laterally spaced elongated receive capacitor electrodes 226, each of which is electrically connected to the load 222 via a high Q receive inductor 228.

[0062] In an embodiment, inductors 218 and 228 are ferrite core inductors. However, one skilled in the art will appreciate that other cores are possible.

[0063] In an embodiment, each of the transmit and receive capacitive electrodes 216 and 226 comprises an elongated element formed of a conductive material. The transmit capacitive electrodes 216 are coplanar. The receive capacitive electrodes 226 are coplanar. In an embodiment, the transmit capacitive electrodes 216 and the receive capacitive electrodes 226 are in parallel planes. In an embodiment, the transmit capacitive electrodes 216 and the receive capacitive electrodes 226 are generally in the form of rectangular flat plates.

[0064] Although the transmit capacitive electrodes 216 and the receive capacitive electrodes 226 have been described as laterally spaced elongated electrodes, those skilled in the art will appreciate that other configurations are possible, including but not limited to concentric, coplanar, circular, elliptical, disc-shaped electrodes, etc. Other suitable electrode configurations are described in U.S. Patent No. 9,979,206 to Nyberg et al., filed on September 4, 2015, the relevant portions of which are incorporated herein by reference.

[0065] Although inductors 218 and 228 are Figure 2 2 and 222. In the drawings, inductors 218 and 228 are shown as being connected in series to power source 212 and load 222, respectively, but those skilled in the art will appreciate that inductors 218 and 228 may be connected in parallel to power source 212 and load 222, respectively.

[0066] During operation, power is transferred from the power supply 212 to the transmit capacitive electrode 216 via the high-Q transmit inductor 218. In particular, the power signal transferred from the power supply 212 to the transmit capacitive electrode 216 via the high-Q transmit inductor 218 excites the transmit resonator 214, causing the transmit resonator 214 to generate an electric field. When a receiver 220 tuned to the same resonant frequency as the transmitter 210 is placed within the resonant electric field, the receive resonator 224 extracts power from the transmit resonator 214 via resonant electric field coupling. The extracted power is then transferred from the receive resonator 224 to the load 222. Because the power transfer is highly resonant, the transmit and receive capacitive electrodes 216 and 226, respectively, do not need to be close or well aligned as in a non-resonant electric field power transfer system. Although the transmit resonator 214 can generate a magnetic field, little, if any, power is transferred via magnetic field coupling.

[0067] When the transmit and receive capacitive electrodes 216 and 226, respectively, are substantially aligned, power is transferred as previously described. When the capacitive electrodes 216 and 226 are not substantially aligned, power transfer may be reduced or not occur at all.

[0068] In order to provide greater positional freedom for the resonator, a transmitting resonator according to one aspect of the present disclosure is provided. Figure 3 A transmit resonator is shown, generally identified by reference numeral 300. As described below, the transmit resonator 300 is configured to generate an electric field to transfer electrical energy to one or more receive resonators. The transmit resonator 300 includes two inductors 302, a switch network 304, a capacitive electrode 306, a detector 308, and a controller 310.

[0069] As described below, the inductor 302 is configured to resonate with the capacitive electrode 306 at a resonant frequency to generate an electric field. The inductor 302 is electrically connected to the switch network 304. In an embodiment, the inductor 302 is a ferrite core inductor. The inductor 302 is a static inductor. However, those skilled in the art will appreciate that other cores are also possible. In addition, those skilled in the art will appreciate that more than two inductors 302 or less than two inductors 302 may also be used.

[0070] The capacitor electrodes 306 are composed of N x M capacitor electrodes. The capacitor electrodes 306 are arranged in a grid pattern, where N is the number of columns in the grid and M is the number of rows in the grid. Each capacitor electrode 306 is electrically connected to the switch network 304. The capacitor electrodes 306 are coplanar. The capacitor electrodes 306 are coplanar in the xy plane. In an embodiment, each capacitor electrode 306 is a planar square plate electrode having the same size.

[0071] The switch network 304 is configured to control which electrodes 306 resonate with the inductor 302 to generate an electric field. The switch network 304 is electrically connected to the inductor 302 and the controller 310. The switch network 304 electrically connects two inductors 302 to each capacitive electrode 306. In an embodiment, the switch network 306 includes a plurality of interconnected switches. In an embodiment, the switch network 304 includes two inputs, one input for each inductor 302 and N x M x 2 outputs. Each output is electrically connected to a single capacitive electrode 306. Each capacitive electrode 306 is electrically connected to two outputs of the switch network 304. The switch network 304 is configured to control the connection of the capacitive electrode 306 to the inductor 302. At any given time, one capacitive electrode 306 can be connected to two inductors 302, a single inductor 302, or no inductor 302 via the switch network 304. When the capacitive electrode 306 is not connected to any inductor 302 , the capacitive electrode 306 may become electrically floating or grounded, depending on the requirements of the transmit resonator 300 .

[0072] The detector is configured to detect impedance. The detector is electrically connected to the capacitive electrode 306. The detector is communicatively connected to the controller 310. In an embodiment, the detector includes a first detector 308, which is configured to detect the impedance presented to the electrode 306. The first detector 308 includes at least one circuit. In an embodiment, the first detector 308 also includes a phase detector. The circuit includes an electrical component, which is configured to detect impedance by applying a voltage and detecting a current. The phase detector is configured to detect a phase. The first detector 308 determines the impedance presented to the electrode 306 using the detected current and the detected phase. The first detector 308 determines the impedance presented at each electrode 306.

[0073] As previously described, the detector is communicatively connected to the controller 310. The detected impedance is transmitted to the controller 310. In an embodiment, the detector is electrically connected to the controller 310. Specifically, in an embodiment, the first detector 308 transmits all detected impedances to the controller 310. In an embodiment, the first detector 308 is electrically connected to the controller 310. In an embodiment, the detected impedance is transmitted to the controller 310 via a wired connection between the controller 310 and the first detector 308.

[0074] The controller 310 is configured to control the switch network 304 to determine which electrodes 306 are connected to which inductors 302. The controller 310 is communicatively connected to the switch network 304 and the first detector 308. In an embodiment, the controller 310 is electrically connected to the switch network 304 via a wired connection. The controller 310 is configured to send a control signal to the switch network 304 to control which electrodes 306 are connected to which inductors 302 based on the impedance from the first detector 308. Although the controller 310 and the switch network 304 have been described as separate and distinct elements, those skilled in the art will appreciate that the controller 310 and the switch network 304 may be combined into a single element.

[0075] In an embodiment, the controller 310 is a microcontroller. Although the controller 310 has been described as a microcontroller, those skilled in the art will appreciate that other configurations are possible. In another embodiment, the controller 310 includes one or more of software, hardware, a digital logic controller (DLC), and a microprocessor.

[0076] Those skilled in the art will appreciate that other configurations are possible. In another embodiment, the detected impedance is sent to the controller 310 via wireless communication. The controller 310 and the first detector 308 are not electrically connected via a wired connection. In addition, in another embodiment, the controller 310 is configured to send a control signal to the switch network 304 via wireless communication. The controller 310 is not electrically connected to the switch network 304 via a wired connection. Exemplary wireless communication schemes include WiFi. TM and Bluetooth TM .

[0077] In an embodiment, the transmitting resonator 300 further includes a passive electrode 320 as described in U.S. Patent Application No. 16 / 138,344 filed on September 21, 2018, the relevant portions of which are incorporated herein by reference. The passive electrode 320 includes the electrode 306 to at least partially eliminate environmental effects affecting the electrode 306. The passive electrode 320 is adjacent to the electrode 306. In an embodiment, the passive electrode 320 and the electrode 306 have parallel planes. The passive electrode 320 includes an elongated element. The elongated element is formed of a conductive material. The elongated element is in the form of a generally rectangular flat plate.

[0078] In operation, the first detector 308 detects the impedance presented at the capacitive electrodes 306. Specifically, the first detector 308 detects the impedance presented at all electrodes 306 either continuously (one electrode 306 at a time) or simultaneously. When at least one receiving resonator is presented to two or more electrodes 306 (a subset of the capacitive electrodes 306 or all of the capacitive electrodes 306) and the detected impedance is greater than a threshold impedance, the first detector 308 sends the detected impedance to the controller 310. The threshold impedance is the lowest value of the impedance range that allows the transmitting resonator 300 to resonate at the resonant frequency. In an embodiment, the resonant frequency is 13.56 MHz. The controller 310 applies logic to determine which electrode 306 has been presented with the impedance.

[0079] One of ordinary skill in the art will recognize that the logic may include the use of an algorithm, such as, but not limited to, a binary search method, for finding which transmit capacitor electrodes 306 should be connected to the transmit inductor 302 when a receiver is placed into the system. In another embodiment, more information about the possible sizes and shapes of the receiving resonators may enable logic involving increasingly complex and time-saving algorithms to be used within the system, depending on the known constraints of a given wireless power transfer system. In another embodiment, the logic may include the implementation of a genetic algorithm combined with a neural network to help the system quickly find a receiver. One of ordinary skill in the art will recognize that other algorithms are also possible.

[0080] The controller 310 then sends a signal to the switch network 304 to connect two or more electrodes 306 present with the receiving resonator to the inductor 302 and disconnect all other electrodes 306 from the inductor 302. The two or more electrodes 306 and the inductor 302 resonate at a resonant frequency to generate an electric field. The receiving resonator tuned to the same resonant frequency extracts electrical energy from the electric field via resonant electric field coupling. Although the transmitting resonator 300 can generate electromagnetic energy, most of the power transfer is via the electric field. Little, if any, power is transferred via magnetic induction or resonant magnetic induction.

[0081] Since the capacitor electrodes 306 have the same size, the capacitance between the capacitor electrodes 306 has a specific repeating value. Figure 4 and Figure 5 Schematic representation of capacitor electrodes 306 in a grid pattern is shown, where N (the number of columns in the grid) is 4, and M (the number of rows in the grid) is 4. The capacitance between different pairs of capacitor electrodes 306 is as follows: Figure 4 and Figure 5 shown. Figure 4 Four different capacitance values ​​A, B, C, and D between adjacent capacitive electrodes 306 are shown. Figure 5Four different capacitance values, E, F, G, and H, are shown between the diagonal capacitive electrodes 306. The capacitance value between the capacitive electrode 306 and the passive electrode 320 is not shown.

[0082] Although a particular transmit resonator 300 has been described, those skilled in the art will appreciate that other configurations are possible. Figure 6 Another embodiment of a transmit resonator is shown, generally identified by reference numeral 400. As described below, the transmit resonator 400 is configured to generate an electric field to transfer electrical energy to one or more receive resonators. The transmit resonator 400 includes two inductors 402, a switch network 404, a capacitive electrode 406, a detector, and a controller 410. In an embodiment, the transmit resonator 400 also includes a passive electrode 420 as described in U.S. Patent Application No. 16 / 138,344 filed on September 21, 2018, the relevant portions of which are incorporated herein by reference. Unless otherwise noted, the inductor 402, the switch network 404, the capacitive electrode 406, the controller 410, and the passive electrode 420 are the same as the inductor 302, the switch network 304, the capacitive electrode 306, the controller 310, and the passive electrode 320 described above, respectively.

[0083] The detector is configured to detect impedance. In an embodiment, the detector includes a first detector 408 and a second detector 412. The first detector 408 is configured to detect impedance presented to the electrode 406. The first detector 408 is electrically connected to the capacitive electrode 406. The first detector 408 is communicatively connected to the controller 410.

[0084] The first detector 408 includes at least one circuit. In an embodiment, the first detector 408 also includes a phase detector. The circuit includes an electrical component configured to detect impedance by applying a voltage and detecting a current. The phase detector is configured to detect a phase. The first detector 408 determines the impedance presented to the electrode 406 using the detected current and the detected phase. The first detector 408 determines the impedance presented at each electrode 406.

[0085] As previously described, the first detector 408 is communicatively connected to the controller 410. The detected impedance is transmitted to the controller 410. In an embodiment, the first detector 408 is electrically connected to the controller 410. The detected impedance is transmitted to the controller 410 via a wired connection between the controller 410 and the first detector 408.

[0086] The second detector 412 is configured to detect the impedance at the inductor 402. The second detector 412 is electrically connected to the inductor 402. The second detector 412 is communicatively connected to the controller 410. The second detector 412 includes at least one circuit. In an embodiment, the second detector 412 also includes a phase detector. The circuit includes an electrical component that is configured to detect impedance by applying a voltage and detecting a current. The phase detector is configured to detect a phase. The second detector 412 determines the impedance at the inductor 402 using the detected current and the detected phase.

[0087] As previously described, the second detector 412 is communicatively connected to the controller 410. The impedance detected at the inductor 402 is transmitted to the controller 410. In an embodiment, the second detector 412 is electrically connected to the controller 410. The impedance detected at the inductor 402 is transmitted to the controller 410 via a wired connection between the controller 410 and the second detector 412.

[0088] In an embodiment, the controller 410 is a microcontroller. Although the controller 410 has been described as a microcontroller, those skilled in the art will appreciate that other configurations are possible. In another embodiment, the controller 410 includes one or more of software, hardware, a digital logic controller (DLC), and a microprocessor.

[0089] Those skilled in the art will appreciate that other configurations are possible. In another embodiment, the detected impedance is sent to the controller 410 via wireless communication. The controller 410 and the first detector 408 are not electrically connected via a wired connection. The controller 410 and the second detector 412 are not electrically connected via a wired connection. In addition, in another embodiment, the controller 410 is configured to transmit the control signal to the switch network 404 via wireless communication. The controller 410 is not electrically connected to the switch network 404 via a wired connection. Exemplary wireless communication schemes include WiFi TM and Bluetooth TM .

[0090] In operation, the first detector 408 detects the impedance presented at the capacitive electrodes 406. When at least one receiving resonator is presented to two or more capacitive electrodes 406 (a subset of the capacitive electrodes 406 or all of the capacitive electrodes 406) and the detected impedance is greater than a threshold impedance, the first detector 408 sends the detected impedance to the controller 410. The threshold impedance is the lowest value of the impedance range that allows the transmitting resonator 400 to resonate at the resonant frequency. In an embodiment, the resonant frequency is 13.56 MHz. The second detector 412 detects the impedance at the inductor 402. The second detector 412 sends the detected impedance at the inductor 402 to the controller 410. The controller 410 applies logic to determine which electrode 406 has been presented with the impedance.

[0091] One of ordinary skill in the art will recognize that the logic may include the use of an algorithm, such as, but not limited to, a binary search method, for finding which transmit capacitor electrode 306 should be connected to the transmit inductor 302 when a receiver is placed into the system. In another embodiment, more information about the possible sizes and shapes of the receiving resonator may make logic involving increasingly complex and time-saving algorithms possible and usable within the system, depending on the known constraints of a given wireless power transfer system. In another embodiment, the logic may include the implementation of a genetic algorithm combined with a neural network to help the system quickly find a receiver. One of ordinary skill in the art will recognize that other algorithms are also possible.

[0092] The controller 410 then sends a signal to the switch network 404 to connect two or more electrodes 406 present with the receive resonator to the inductor 402 and disconnect all other electrodes 406 from the inductor 402. The controller 410 compares the impedance detected at the capacitive electrodes 406 from the first detector 408 with the impedance detected at the inductor 402 from the second detector 412 to ensure that the inductor 402 has an impedance within an impedance range that allows the transmit resonator 400 to resonate at the resonant frequency. If the inductor 402 has an impedance within the impedance range, the controller 410 takes no further action. If the inductor 402 has an impedance that is not within the impedance range, the controller 410 disconnects all capacitive electrodes 406 from the inductor 402 via a command to the switch network 404. This ensures that the components of the transmit resonator 400 are not damaged.

[0093] When two or more electrodes 406 are connected to inductor 402 via switch network 404, two or more electrodes 406 resonate with inductor 402 at a resonant frequency to generate an electric field. A receiving resonator tuned to the same resonant frequency extracts electrical energy from the electric field via resonant electric field coupling. Although transmitting resonator 400 can generate electromagnetic energy, most electrical energy transfer is via the electric field. Very little, if any, electrical energy is transferred via magnetic induction or resonant magnetic induction.

[0094] The transmitting resonators 300 and 400 may be incorporated into a wireless power transmission system. Figure 7 Such a wireless power transfer system is shown in accordance with one aspect of the present disclosure and is generally identified by reference numeral 500. System 500 includes a transmitter 502 and a receiver 510.

[0095] The transmitter 502 includes a power supply 504, an inverter 506, and a transmitting resonator 400. The power supply 504 is configured to supply power to the inverter 506. The power supply 504 is electrically connected to the inverter 506. The power supply 504 provides direct current (DC) power to the inverter 506. The inverter 506 is configured to convert the DC power from the power supply 504 into alternating current (AC) power. The inverter 506 is electrically connected to the power supply 504 and the second detector 412 of the transmitting resonator 400. In an embodiment, the inverter 506 includes an impedance matching circuit. The impedance matching circuit is configured to match the input impedance of the transmitter 502 to the output impedance of the transmitter 502.

[0096] Receiver 510 includes load 512, rectifier 514 and receiving resonator 520. Load 512 includes a device that needs power. For example, load 512 includes a battery. Load 512 is electrically connected to rectifier 514. Rectifier 514 is configured to convert AC power from receiving resonator 520 into DC power. Rectifier 514 is electrically connected to load 512 and receiving resonator 520.

[0097] The receive resonator 520 is configured to extract electrical energy from the electric field generated by the transmit resonator 400 via resonant electric field coupling. The receive resonator 520 includes two receive inductors 522 and two receive capacitive electrodes 526. In an embodiment, the receive resonator also includes a receive passive electrode 530.

[0098] The receive inductors 522 are configured to resonate with the receive capacitor electrodes 526 to generate an electric field having the same resonant frequency as the transmit resonator 400. Each receive inductor 522 is connected to a single receive capacitor electrode 526. In an embodiment, the receive inductors 522 are ferrite core inductors. The receive inductors 522 are static inductors. However, those skilled in the art will appreciate that other cores are possible.

[0099] The receiving capacitor electrodes 526 are coplanar. In an embodiment, each receiving capacitor electrode 526 is a planar square plate electrode having the same size. The receiving capacitor electrodes 526 are aligned so that the receiving capacitor electrodes 526 can overlap and align with the two capacitor electrodes 406 of the transmitting resonator 400.

[0100] The receiving passive electrode 530 is as described in U.S. Patent Application No. 16 / 138,344 filed on September 21, 2018, the relevant parts of which are incorporated herein by reference. The receiving passive electrode 530 includes the receiving capacitor electrode 526 to at least partially eliminate environmental effects affecting the receiving capacitor electrode 526. The receiving passive electrode 530 is adjacent to the receiving capacitor electrode 526. The receiving passive electrode 530 and the receiving capacitor electrode 526 have parallel planes. The receiving passive electrode 530 includes an elongated element. The elongated element is formed of a conductive material. The elongated element is in the form of a substantially rectangular flat plate with opposing main surfaces.

[0101] In operation, DC power is transmitted from the power source 504 to the inverter 506. The inverter 506 converts the DC power into alternating AC power, which is transmitted to the transmit resonator 400. The first detector 408 detects the impedance presented at the capacitive electrodes 406. When the receive capacitive electrode 526 of the receive resonator 520 is at least partially aligned with two capacitive electrodes 406 (a subset of the capacitive electrodes 406) of the transmit resonator 400, and the detected impedance is greater than a threshold impedance, the first detector 408 sends the detected impedance to the controller 410. The threshold impedance is the lowest value of the impedance range that allows the transmit resonator 400 to resonate at the resonant frequency. In an embodiment, the resonant frequency is 13.56 MHz. The second detector 412 detects the impedance at the inductor 402. The second detector 412 sends the detected impedance at the inductor 402 to the controller 410. The controller 410 applies logic to determine which electrode 406 has been presented with impedance.

[0102] One of ordinary skill in the art will recognize that the logic may include the use of an algorithm, such as, but not limited to, a binary search method, for finding which transmit capacitor electrodes 306 should be connected to the transmit inductor 302 when a receiver is placed into the system. In another embodiment, more information about the possible sizes and shapes of the receiving resonators may enable logic involving increasingly complex and time-saving algorithms to be used within the system, depending on the known constraints of a given wireless power transfer system. In another embodiment, the logic may include the implementation of a genetic algorithm combined with a neural network to help the system quickly find a receiver. One of ordinary skill in the art will recognize that other algorithms are also possible.

[0103] The controller 410 then sends a signal to the switch network 404 to connect two or more electrodes 406 present with the receive capacitive electrode 526 to the inductor 402 and disconnect all other electrodes 406 from the inductor 402. The controller 410 compares the impedance detected at the capacitive electrode 406 from the first detector 408 with the impedance detected at the inductor 402 from the second detector 412 to ensure that the inductor 402 has an impedance within an impedance range that allows the transmit resonator 400 to resonate at the resonant frequency. If the inductor 402 has an impedance within the impedance range, the controller 410 takes no further action.

[0104] The AC power from the inverter 506 excites the two electrodes 406 and the inductor 402, causing the two electrodes 406 and the inductor 402 to resonate at a resonant frequency and generate an electric field. The receiving resonator 526 tuned to the same resonant frequency extracts power from the electric field via resonant electric field coupling. Although the transmitting resonator 400 can generate electromagnetic energy, most power transmission is via the electric field. There is little, if any, power transmitted via magnetic induction or resonant magnetic induction. The power received at the receiving resonator 520 is converted from AC power to DC power by the rectifier 514 applied to the load 512.

[0105] If the impedance detected at the inductor 402 is not within the impedance range, the controller 410 disconnects all capacitive electrodes 406 from the inductor 402 via a signal sent to the switch network 404. This ensures that the components of the transmit resonator 400 are not damaged.

[0106] When the receive capacitive electrodes 526 of the receive resonator 520 are no longer sufficiently aligned with at least two capacitive electrodes 406 of the transmit resonator 400, the first detector 408 detects that the impedance presented at the respective electrodes 406 of the transmit resonator 400 is outside of an impedance range that allows the transmit resonator 400 to resonate at the resonant frequency. The first detector 408 sends the detected impedance to the controller 410. The controller 410 applies logic and determines that the receive capacitive electrodes 526 are no longer sufficiently aligned.

[0107] One of ordinary skill in the art will recognize that the logic may include the use of an algorithm, such as, but not limited to, a binary search method, for finding which transmit capacitor electrodes 306 should be connected to the transmit inductor 302 when a receiver is placed into the system. In another embodiment, more information about the possible sizes and shapes of the receiving resonators may enable logic involving increasingly complex and time-saving algorithms to be used within the system, depending on the known constraints of a given wireless power transfer system. In another embodiment, the logic may include the implementation of a genetic algorithm combined with a neural network to help the system quickly find a receiver. One of ordinary skill in the art will recognize that other algorithms are also possible.

[0108] The controller 410 determines that none of the capacitive electrodes 406 of the transmit resonator 400 should be connected to the inductor 402. The controller 410 then sends a signal to the switch network 404 to disconnect all of the capacitive electrodes 406 from the inductor 402 so that no power is transferred from the transmit resonator 400.

[0109] When the receiving capacitor electrode 526 moves to align with two different capacitor electrodes 406 of the transmitting resonator 400, the first detector 408 detects that the impedance presented at the two previously aligned capacitor electrodes 406 has dropped below the threshold impedance, and the impedance presented at the different two capacitor electrodes 406 is greater than the threshold impedance. The first detector 408 sends all detected impedances to the controller 410. The controller 410 then sends a signal to disconnect the two previously aligned capacitor electrodes 406 from the inductor 402 and connect the different two capacitor electrodes 406 to the inductor 402. The AC power from the inverter 506 excites the different two electrodes 406 and the inductor 402, so that the different two electrodes 406 and the inductor 402 resonate at the resonant frequency and generate an electric field. The receiving resonator 526 tuned to the same resonant frequency extracts power from the electric field via resonant electric field coupling. Although the transmitting resonator 400 can generate electromagnetic energy, most of the power transmission is via the electric field. There is little (if any) power transmitted via magnetic induction or resonant magnetic induction. The power received at the receiving resonator 520 is converted from AC power to DC power by the rectifier 514 applied to the load 512 .

[0110] As will be appreciated, the described wireless power transfer system 500 allows the receiving resonator 520 to move around in the grid of capacitive electrodes 406 of the transmitting resonator 400 and still maintain the resonant electric field coupling required for power transfer from the transmitter 502 to the receiver 510 .

[0111] Although the operation of the wireless power transfer system 500 has been described when the receive capacitive electrode 526 overlaps and is aligned with the capacitive electrode 406 of the transmit resonator 400, wireless power transfer may still occur when the receive capacitive electrode 526 is not completely overlapped and / or aligned with the capacitive electrode 406 of the transmit resonator 400.

[0112] Figure 8A portion of a wireless power transfer system is shown, generally identified by reference numeral 600. Unless otherwise noted, the wireless power transfer system 600 is the same as the previously described wireless power transfer system 500. The wireless power transfer system 600 includes a transmitter 502, which includes a transmit resonator 400. In an embodiment, the capacitive electrodes 406 of the transmit resonator 400 are arranged in a grid pattern, where N (the number of columns in the grid) is 3 and M (the number of rows in the grid) is 3.

[0113] The wireless power transmission system 600 also includes a receiver 510. In an embodiment, the receiving capacitive electrode 526 only partially overlaps the capacitive electrode 406 of the transmitting resonator 400. In an embodiment, the receiving capacitive electrode 526 is not aligned with the capacitive electrode 406 of the transmitting resonator 400.

[0114] During operation, the first detector 408 can still detect sufficient impedance from the receive resonator 520 to resonate the two capacitive electrodes 406 and the inductor 402 of the transmit resonator 400 that partially overlap the receive capacitive electrode 526, thereby generating an electric field and resonating the two other capacitive electrodes 406 and the inductor 402 of the transmit resonator 400 that also partially overlap the receive capacitive electrode 526. The receive resonator 520 resonates at the resonant frequency of the transmit resonator 400 and extracts power from the two generated electric fields via resonant electric field coupling. Although the efficiency of power transfer from each individual electric field may be lower than the power transfer efficiency of a single electric field generated when the receive capacitive electrode 526 and the capacitive electrode 406 of the transmit resonator 400 are aligned, a certain amount of wireless power transfer may still occur.

[0115] Although a particular wireless power transfer system 500 having a single receiver 510 has been described, those skilled in the art will appreciate that a wireless power transfer system may include multiple receivers. Fig. 9 A portion of a wireless power transfer system is shown, generally identified by reference numeral 700. Unless otherwise noted, the wireless power transfer system 700 is the same as the previously described wireless power transfer system 500. The wireless power transfer system 700 includes a transmitter 502, which includes a transmit resonator 400. In an embodiment, the capacitive electrodes 406 of the transmit resonator 400 are arranged in a grid pattern, where N (the number of columns in the grid) is 4 and M (the number of rows in the grid) is 4.

[0116] The wireless power transmission system 700 also includes a receiver 510 including a receiving resonator 520. Two receiving capacitor electrodes 526 of the receiving resonator 520 overlap and align with two capacitor electrodes 406 of the transmitting resonator 400, so that power is transmitted from the transmitting resonator 400 to the receiving resonator 520 via resonant electric field coupling.

[0117] The wireless power transmission system 700 further includes a second receiver. Unless otherwise specified, the second receiver is the same as the receiver 510. The second receiver includes a second receiving resonator, which includes four receiving capacitor electrodes. The second receiving resonator also includes a second receiving passive electrode 704.

[0118] The second receiving passive electrode 704 is as described in U.S. Patent Application No. 16 / 138,344 filed on September 21, 2018, the relevant parts of which are incorporated herein by reference. The second receiving passive electrode 704 includes a receiving capacitor electrode of the second receiving resonator to at least partially eliminate environmental influences affecting the receiving capacitor electrode. The second receiving passive electrode 704 is adjacent to the receiving capacitor electrode of the second receiving resonator. The second receiving passive electrode 704 and the receiving capacitor electrode of the second receiving resonator have parallel planes. The second receiving passive electrode 704 includes an elongated element. The elongated element is formed of a conductive material. The elongated element is in the form of a substantially rectangular flat plate with opposing main surfaces.

[0119] In an embodiment, the capacitive receiving electrodes of the second receiver are arranged in a 2x2 grid pattern with the same spacing between adjacent electrodes as the capacitive electrodes 406 of the transmit resonator 400. The capacitive receiving electrodes of the second receive resonator are the same size as the capacitive electrodes 406 of the transmit resonator 400. The receiving capacitive electrodes of the second receive resonator overlap and align with the four capacitive electrodes 406 of the transmit resonator 400, so that electrical energy is transferred from the transmit resonator 400 to the second receive resonator via resonant electric field coupling.

[0120] like Fig. 9 As shown, the transmit resonator 400 can simultaneously power multiple receiver resonators. Since the first detector 408 detects the impedance at each capacitive electrode 406 of the transmit resonator 400, when multiple receiver resonators are presented to the transmit resonator 400, the first detector 408 detects multiple impedances at the multiple capacitive electrodes 406.

[0121] Although a particular wireless power transfer system 500 has been described, those skilled in the art will appreciate that other configurations are possible. Fig.10A portion of a wireless power transmission system is shown, which is generally identified by reference numeral 1000. Unless otherwise specified, the wireless power transmission system 1000 is the same as the aforementioned wireless power transmission system 500. In an embodiment, the capacitor electrodes 406 of the transmitting resonator 400 are arranged in a grid pattern, where N (the number of columns in the grid) is 5 and M (the number of rows in the grid) is 5. Each transmitting capacitor electrode 406 has a width (W) of 50 mm and a length (L) of 50 mm. The gap (G) between adjacent capacitor electrodes 406 is 10 mm. The receiving capacitor electrode 526 is shown only to illustrate its position. Those skilled in the art will understand that during operation, the receiving passive electrode 530 will block the field of view of the receiving capacitor electrode 526. Similar to the capacitor electrodes 406 of the transmitting resonator 400, each receiving capacitor electrode 526 has a width (W) of 50 mm and a length (L) of 50 mm. In addition, each receiving capacitor electrode 526 is separated by a gap (G) of 10 mm. The wireless power transfer system 500 operates at a resonant frequency of 13.56 MHz. The inductance (not shown) of the inductor 402 is 60 μH.

[0122] Although specific capacitive electrodes 306 and 406 have been described, those skilled in the art will appreciate that other configurations are possible. Fig.11 Another embodiment of a capacitive electrode (generally identified by reference numeral 1206) and a passive electrode 1220 of a transmitting resonator is shown.

[0123] Unless otherwise stated, the capacitor electrodes 1206 and the passive electrodes 1220 are the same as the capacitor electrodes 306 and the passive electrodes 320, respectively. In an embodiment, the capacitor electrodes 1206 include twelve (12) capacitor electrodes. The capacitor electrodes 1206 are arranged in a circular pattern. The capacitor electrodes 1206 are generally arranged in two rings, an inner ring and an outer ring. The inner ring is surrounded by the outer ring. Each capacitor electrode 1206 is a segment of one of the inner ring and the outer ring. The capacitor electrodes 1206 are coplanar in the xy plane. In an embodiment, each capacitor electrode 1206 is a planar electrode. Each capacitor electrode 1206 is a segment of a substantially circular ring.

[0124] The passive electrode 1220 includes an element. The element is formed of a conductive material. The element is in the form of a substantially circular plate having opposite main surfaces. The element includes an outer ring and an inner ring. The plane defined by the passive electrode 1220 is parallel to the plane defined by the capacitive electrode 1206.

[0125] The wireless power transmission system 500 includes a transmitter 502, which includes a transmit resonator 400 having an inductor 402, and the inductor 402 has a static inductance. The static inductance of the inductor 402 may limit the ability to transmit power using the plurality of capacitive electrodes 406 of the transmit resonator 400. Transmitting power through the plurality of capacitive electrodes 406 of the transmit resonator 400 may change the transmit side capacitance, causing the wireless power transmission system 500 to detune, thereby significantly reducing the efficiency of the wireless power transmission and increasing losses.

[0126] Although a particular wireless power transfer system 500 has been described, those skilled in the art will appreciate that other configurations are possible. Fig.12 Another embodiment of a wireless power transfer system, generally identified by reference numeral 1300, is shown. Unless otherwise noted, the wireless power transfer system 1300 is identical to the previously described wireless power transfer system 500. The wireless power transfer system 1300 includes a transmitter 1302 and a receiver 510.

[0127] The transmitter 1302 includes a power supply 504, an inverter 506, and a transmit resonator 1310. The power supply 504 is electrically connected to the inverter 506, and the inverter 506 is electrically connected to the transmit resonator 1310. The transmit resonator 1310 includes two variable inductors 1312, a switch network 1314, a capacitive electrode 1326, a detector, and a controller 1320. In an embodiment, the transmit resonator 1310 also includes a passive electrode 1330. The detector also includes a first detector 1318 and a second detector 1332. The inverter 506 is electrically connected to the second detector 1332. The second detector 1332 is electrically connected to the variable inductor 1312. The second detector 1332 is communicatively connected to the controller 1320. The variable inductor 1312 is electrically connected to the switch network 1314. The controller 1320 is electrically connected to each variable inductor 1312. The switch network 1314 is electrically connected to the capacitive electrode 1326. The controller 1320 is communicatively coupled to the switch network 1314. The first detector 1318 is communicatively coupled to the controller 1320.

[0128] In an embodiment, the first detector 1318 and the second detector 1332 are communicatively connected to the controller 1320 via a wired connection. In addition, in an embodiment, the controller 1320 is communicatively connected to the switch network 1314 via a wired connection. Those skilled in the art will appreciate that other configurations are possible. In another embodiment, the first detector 1318, the second detector 1332, and / or the switch network 1314 are not electrically connected to the controller 1320 via a wired connection. The detectors 1318 and 1332 are configured to transmit the detected impedance to the controller 1320 via wireless communication. The controller 1320 is configured to send a control signal to the switch network 1314 via wireless communication. Exemplary wireless communication schemes include WiFi TM and Bluetooth TM .

[0129] Unless otherwise noted, the switch network 1314, capacitive electrode 1326, controller 1320, and passive electrode 1330 are respectively the same as the switch network 404, capacitive electrode 406, controller 410, and passive electrode 420 described previously. Unless otherwise noted, the first detector 1318 and the second detector 1332 are respectively the same as the first detector 408 and the second detector 412 described previously.

[0130] In an embodiment, the variable inductor 1312 is configured to resonate with the capacitive electrode 1326 at a resonant frequency to generate an electric field, which will be described later. In an embodiment, the inductor 1312 is a ferrite core inductor. However, those skilled in the art will appreciate that other cores are also possible. In addition, those skilled in the art will appreciate that more than two inductors 1312 or less than two inductors 1312 may be used.

[0131] Unless otherwise noted, during operation, the wireless power system 1300 operates identically to the wireless power system 500. The controller 1320 receives the impedance from the first detector 1318 and the second detector 1332 and adjusts the inductance of the variable inductor 1312 to maximize electric field coupling.

[0132] Although a particular wireless power transfer system 500 has been described, those skilled in the art will appreciate that other configurations are possible. Fig.13 Another embodiment of a wireless power transfer system, generally identified by reference numeral 1400, is shown. Unless otherwise noted, the wireless power transfer system 1400 is identical to the previously described wireless power transfer system 500. The wireless power transfer system 1400 includes a transmitter 1402 and a receiver 510.

[0133] The transmitter 1402 includes a power supply 504, an inverter 506, and a transmit resonator 1410. The power supply 504 is electrically connected to the inverter 506, and the inverter 506 is electrically connected to the transmit resonator 1410. The transmit resonator 1410 includes a variable inductor 1412, a switch network 1414, a capacitive electrode 1426, a detector, and a controller 1420. In an embodiment, the transmit resonator 1410 also includes a passive electrode 1430. The detector also includes a first detector 1418 and a second detector 1432. The inverter 506 is electrically connected to the second detector 1432. The second detector 1432 is electrically connected to the switch network 1414. The second detector 1432 is communicatively connected to the controller 1420. The switch network 1414 is electrically connected to the variable inductor 1412. The variable inductor 1412 is electrically connected to the capacitive electrode 1426. The first detector 1418 is communicatively connected to the controller 1420. The controller 1420 is electrically connected to each variable inductor 1412 and the switch network 1414. The controller 1420 is communicatively connected to the switch network 1414. The first detector 1418 is communicatively connected to the controller 1420.

[0134] In an embodiment, the first detector 1418 and the second detector 1432 are communicatively connected to the controller 1420 via a wired connection. In addition, in an embodiment, the controller 1420 is communicatively connected to the switch network 1414 via a wired connection. Those skilled in the art will appreciate that other configurations are possible. In another embodiment, the first detector 1418, the second detector 1432, and / or the switch network 1414 are not electrically connected to the controller 1420 via a wired connection. The detectors 1418 and 1432 are configured to transmit the detected impedance to the controller 1420 via wireless communication. The controller 1420 is configured to send a control signal to the switch network 1414 via wireless communication. Exemplary wireless communication schemes include WiFi TM and Bluetooth TM .

[0135] Unless otherwise noted, the switch network 1414, capacitive electrode 1426, controller 1420, and passive electrode 1430 are respectively the same as the switch network 404, capacitive electrode 406, controller 410, and passive electrode 420 described previously. Unless otherwise noted, the first detector 1418 and the second detector 1432 are respectively the same as the first detector 408 and the second detector 412 described previously.

[0136] In an embodiment, there is one variable inductor 1412 for each capacitor electrode 1426. Each capacitor electrode 1426 is connected to a switch network 1414 via a single variable inductor 1412. As described below, the variable inductor 1412 is configured to resonate with the capacitor electrode 1426 at a resonant frequency to generate an electric field. In an embodiment, the inductor 1412 is a ferrite core inductor. However, those skilled in the art will appreciate that other cores are possible.

[0137] Unless otherwise noted, during operation, the operation of the wireless power system 1400 is the same as the wireless power system 500. The controller 1420 receives the impedance from the first detector 1418 and the second detector 1432, and adjusts the inductance of the variable inductor 1412 to maximize the electric field coupling. The switch network 1414 opens or closes the connection between the variable inductor 1412 and the second detector 1432, so that only the capacitive electrode 1426 presenting the receiving resonator and the variable inductor 1412 associated therewith resonate to generate an electric field.

[0138] Although a particular wireless power transfer system 500 has been described, those skilled in the art will appreciate that other configurations are possible. Fig.14 Another embodiment of a wireless power transfer system, generally identified by reference numeral 1500, is shown. Unless otherwise noted, the wireless power transfer system 1500 is identical to the previously described wireless power transfer system 1400. The wireless power transfer system 1500 includes a transmitter 1502 and a receiver 510.

[0139] The transmitter 1502 includes a power source 504, an inverter 506, and a transmit resonator 1510. The power source 504 is electrically connected to the inverter 506, and the inverter 506 is electrically connected to the transmit resonator 1510. The transmit resonator 1510 includes an inductor 1512, a switch network 1514, a capacitive electrode 1526, a detector, and a controller 1520. In an embodiment, the transmit resonator 1510 also includes a passive electrode 1530. The detector also includes a first detector 1518 and a second detector 1532. The inverter 506 is electrically connected to the second detector 1532. The second detector 1532 is electrically connected to the switch network 1514. The second detector 1532 is communicatively connected to the controller 1520. The switch network 1514 is electrically connected to the inductor 1512. The inductor 1512 is electrically connected to the capacitive electrode 1526. The first detector 1518 is communicatively connected to the controller 1520. The switch network 1514 is electrically connected to each inductor 1512. The controller 1520 is communicatively coupled to the switch network 1514 .

[0140] In an embodiment, the first detector 1518 and the second detector 1532 are communicatively connected to the controller 1520 via a wired connection. In addition, in an embodiment, the controller 1520 is communicatively connected to the switch network 1520 via a wired connection. Those skilled in the art will appreciate that other configurations are possible. In another embodiment, the first detector 1518, the second detector 1532, and / or the switch network 1514 are not electrically connected to the controller 1520 via a wired connection. The detectors 1518 and 1532 are configured to transmit the detected impedance to the controller 1520 via wireless communication. The controller 1520 is configured to send a control signal to the switch network 1514 via wireless communication. Exemplary wireless communication schemes include WiFi TM and Bluetooth TM .

[0141] In an embodiment, there is one inductor 1512 for each capacitor electrode 1526. Each capacitor electrode 1526 is connected to a switch network 1514 via a single inductor 1512. As described below, the inductor 1512 is configured to resonate with the capacitor electrode 1526 at a resonant frequency to generate an electric field. The inductor 1512 is a static inductor. In an embodiment, the inductor 1512 is a ferrite core inductor. However, those skilled in the art will appreciate that other cores are possible.

[0142] During operation, the operation of the wireless power system 1500 is the same as the wireless power system 1400 except that the inductor 1512 is a static inductor.

[0143] Although a particular wireless power transfer system 500 has been described, those skilled in the art will appreciate that other configurations are possible. Fig.15 Another embodiment of a portion of a wireless power transmission system (generally identified by reference numeral 1600) is shown. Unless otherwise specified, the wireless power transmission system 1600 is the same as the wireless power transmission system 500. The wireless power transmission system 1600 includes a transmitter and a receiver. The transmitter includes a power supply (not shown), an inverter (not shown), and a transmitting resonator. The power supply is electrically connected to the inverter. The inverter is electrically connected to the transmitting resonator.

[0144] As previously described, the transmit resonator is configured to generate an electric field to transfer electrical energy to one or more receive resonators. The transmit resonator includes two inductors (not shown) and two transmit capacitor electrodes 1210. The inductors are electrically connected to the transmit capacitor electrodes 1210. The transmit capacitor electrodes 1210 are segments of a ring. The transmit capacitor electrode 1210 includes a first segment as a segment of an outer ring and a second segment as a segment of an inner ring. In an embodiment, each transmit capacitor electrode 1210 is a planar electrode. The transmit capacitor electrodes 1210 are coplanar.

[0145] The receiver includes a receiving resonator, a load (not shown), and a rectifier (not shown). The load is electrically connected to the rectifier. The rectifier is electrically connected to the receiving resonator. The load and the rectifier are the same as the load 512 and the rectifier 514, respectively, and will not be described further. The receiving resonator is configured to extract electrical energy from the electric field generated by the transmitting resonator 400 via resonant electric field coupling. The receiving resonator includes two inductors (not shown), a receiving capacitor electrode 1606, a switching network (not shown), a detector, and a controller (not shown). Unless otherwise stated, the switching network, the detector, and the controller are the same as the aforementioned switching network 404, the detector, and the controller 410 of the transmitting resonator 400, respectively. The inductor is electrically connected to the receiving capacitor electrode 1606.

[0146] Unless otherwise specified, the receiving capacitor electrodes 1606 are the same as the capacitor electrodes 406. In an embodiment, the receiving capacitor electrodes 1606 include twelve (12) capacitor electrodes. The receiving capacitor electrodes 1606 are arranged in a circular pattern. The receiving capacitor electrodes 1606 are generally arranged in two rings, an inner ring and an outer ring. The inner ring is surrounded by the outer ring. Each receiving capacitor electrode 1606 is a segment of the inner ring or the outer ring. The receiving capacitor electrodes 1606 are coplanar. In this embodiment, each receiving capacitor electrode 1606 is a planar electrode.

[0147] Fig.16 Another embodiment of a portion of a wireless power transmission system is shown, which is generally identified by reference numeral 1700. Unless otherwise specified, the wireless power transmission system 1700 is the same as the wireless power transmission system 1600. The wireless power transmission system 1700 includes a transmitter and a receiver. The transmitter includes a power supply (not shown), an inverter (not shown), and a transmitting resonator. The power supply is electrically connected to the inverter. The inverter is electrically connected to the transmitting resonator.

[0148] As previously described, the transmit resonator is configured to generate an electric field to transfer electrical energy to one or more receive resonators. The transmit resonator includes two inductors (not shown) and two transmit capacitor electrodes 1212. The inductors are electrically connected to the transmit capacitor electrodes 1212. The transmit capacitor electrodes 1212 are segments of a ring. The transmit capacitor electrodes 1212 include a first segment that is a segment of an outer ring and a second segment that is a segment of an inner ring. In an embodiment, each transmit capacitor electrode 1212 is a planar electrode. The transmit capacitor electrodes 1212 are coplanar.

[0149] The receiver includes a receiving resonator, a load (not shown), and a rectifier (not shown). The load is electrically connected to the rectifier. The rectifier is electrically connected to the receiving resonator. The load and the rectifier are the same as the load 512 and the rectifier 514, respectively, and will not be described further. The receiving resonator is configured to extract electrical energy from the electric field generated by the transmitting resonator 400 via resonant electric field coupling. The receiving resonator includes two receiving inductors (not shown) and two receiving capacitor electrodes 1706. The inductors are electrically connected to the receiving capacitor electrodes 1706.

[0150] Unless otherwise specified, the receiving capacitor electrode 1706 is the same as the capacitor electrode 406. In an embodiment, the receiving capacitor electrode 1706 includes two ring electrodes, namely an outer ring electrode and an inner ring electrode. The inner ring electrode is surrounded by the outer ring electrode. The receiving capacitor electrodes 1706 are coplanar. In an embodiment, each receiving capacitor electrode 1706 is a planar electrode.

[0151] The wireless power transmission systems 1600 and 1700 are simulated. Fig.15 As shown, the two transmit capacitor electrodes 1210 overlap and are aligned with the two receive capacitor electrodes 1606 .

[0152] In an embodiment, the outer receiving capacitor electrode 1606 and the outer transmitting capacitor electrode 1210 have an outer radius of 1200 mm and an inner radius of 1000 mm. The inner receiving capacitor electrode 1606 and the inner transmitting capacitor electrode 1210 have an outer radius of 700 mm and an inner radius of 400 mm. Each receiving capacitor electrode 1606 is separated from the adjacent receiving capacitor electrode 1606 in the same ring by 100 mm. The spacing between the outer radius of the inner receiving capacitor electrode 1606 and the inner radius of the outer receiving capacitor electrode 1606 is 200 mm. Similarly, the gap between the outer radius of the inner transmitting capacitor electrode 1210 and the inner radius of the outer transmitting capacitor electrode 1210 is 300 mm. The wireless power transmission system 1600 transfers 45 watts of power from the transmitting resonator to the receiving resonator. The spacing distance between the transmitting resonator and the receiving resonator is 100 mm. The radio frequency (RF) efficiency of the power transmission between the resonators is 98.2%. The resonant frequency of the wireless power transmission system 1600 is 13.56 MHz. The inductance of the inductor of the transmitting resonator is 5.7 μH. The inductance of the inductor of the receiving resonator is 8.8 μH.

[0153] like Fig.16As shown, the transmitting capacitor electrode 1212 overlaps the receiving capacitor electrode 1706. In an embodiment, the outer receiving capacitor electrode 1706 and the outer transmitting capacitor electrode 1212 have an outer radius of 1200 mm and an inner radius of 1000 mm. The inner receiving capacitor electrode 1706 and the inner transmitting capacitor electrode 1212 have an outer radius of 700 mm and an inner radius of 400 mm. The gap between the outer radius of the inner receiving capacitor electrode 1706 and the inner radius of the outer receiving capacitor electrode 1706 is 300 mm. Similarly, the gap between the outer radius of the inner transmitting capacitor electrode 1212 and the inner radius of the outer transmitting capacitor electrode 1212 is 300 mm. The wireless power transmission system 1700 transfers 45 watts of power from the transmitting resonator to the receiving resonator. The spacing distance between the transmitting resonator and the receiving resonator is 100 mm. The radio frequency efficiency of the power transmission between the resonators is 97.8%. The resonant frequency of the wireless power transmission system 1700 is 13.56 MHz. The inductance of the inductor of the transmitting resonator is 4.6 μH. The inductance of the inductor of the receiving resonator is 1.2 μH.

[0154] The simulation results are as follows Fig.17 and Fig.18 shown. Fig.17 is a diagram of the electric field of the wireless power transmission system 1600. Specifically, Fig.17 The electric field is shown plotted on a center plane between a transmit resonator and a receive resonator of a wireless power transfer system 1600 .

[0155] Fig.18 is a diagram of the electric field of the wireless power transmission system 1700. Specifically, Fig.18 The electric field plotted on a center plane between a transmit resonator and a receive resonator of the wireless power transfer system 1700 is shown.

[0156] exist Fig.17 and Fig.18 In the area where the transmitting capacitor electrodes 1210 and 1212 overlap with the receiving capacitor electrodes 1606 and 1706, respectively, the electric field is larger. In the area where the transmitting capacitor electrode 1210 does not overlap with the receiving capacitor electrode 1606, the electric field of the wireless power transmission system 1600 is lower than the electric field of the wireless power transmission system 1700 in the area where the transmitting capacitor electrode 1212 does not overlap with the receiving capacitor electrode 1706. Therefore, the electric field contained in the wireless power transmission system 1600 is better than the electric field contained in the wireless power transmission system 1700. The improved containment reduces the probability of human body exposure to RF fields. In addition, the improved containment can prevent electromagnetic interference. In addition, the improved containment reduces the specific absorption rate (SAR) value.

[0157] Although a particular wireless power transfer system 500 has been described, those skilled in the art will appreciate that other configurations are possible. Fig.19 Another embodiment of a wireless power transfer system, generally identified by reference numeral 2000, is shown. Unless otherwise noted, wireless power transfer system 2000 is identical to wireless power transfer system 500. In an embodiment, the transmitting resonator includes capacitive electrodes 2006 in a grid pattern, where N (the number of columns in the grid) is 2 and M (the number of rows in the grid) is 2. In an embodiment, capacitive electrodes 2006 are rectangular plate electrodes.

[0158] The wireless power transmission system 2000 is simulated. In this embodiment, each capacitor electrode 2006 has a length of 330 mm and a width of 100 mm. The gap between the long sides of the capacitor electrode 2006 is 50 mm. The gap between the short sides of the capacitor electrode 2006 is 30 mm. The length of the receiving capacitor electrode 526 is 330 mm and the width is 100 mm. The gap between the receiving capacitor electrodes is 50 mm. The gap between the capacitor electrode 2006 of the transmitting resonator and the receiving capacitor electrode 526 is 25 mm.

[0159] During the simulation, the receiving capacitor electrode 526 initially moves from overlapping and being aligned with the two capacitor electrodes 2006 (Tx1) of the transmitting resonator 400. Then, the receiving capacitor electrode 526 moves toward the other two capacitor electrodes 2006 (Tx2) of the transmitting resonator 400 until it overlaps and is aligned with the other two capacitor electrodes 2006 of the transmitting resonator 400.

[0160] Fig. 20 is a graph of the RF efficiency of the wireless power transmission system 2000. The RF efficiency of the wireless power transmission system 2000 is defined as the efficiency of wireless power transmission between the transmission resonator 400 and the reception resonator 510 of the wireless power transmission system 2000. Fig. 20 The solid curve in represents the time when the two capacitive electrodes 2006 ( Tx1 ) of the transmitting resonator 400 are activated. Fig. 20 The dashed curve in represents the time when the other two capacitive electrodes 2006 (Tx2) of the transmit resonator 400 are activated. A distance of 0 mm indicates that the receive capacitive electrode 526 overlaps and is aligned with Tx1. A distance of 360 mm indicates that the receive capacitive electrode 526 overlaps and is aligned with Tx2.

[0161] The vertical solid line represents the distance at which the receive capacitor electrode 526 begins to overlap with Tx2. The vertical dashed line represents the distance at which the receive capacitor electrode 526 does not overlap with Tx1. By switching the capacitor electrode 2006 pair that generates an electric field to transfer power to the receive resonator 510, the RF efficiency can be maintained at greater than 90% during the movement of the receive capacitor electrode 526. For distances between 150 mm and 250 mm, both Tx1 and Tx2 can achieve efficient wireless power transmission.

[0162] Fig.21 2 is a graph of the input impedance of the transmitting resonator 400 of the wireless power transmission system 2000. The solid line curve represents the time when Tx1 generates an electric field to transmit power to the receiving resonator 510, and the time when Tx2 is not generating an electric field. The dashed line curve represents the time when Tx2 generates an electric field to transmit power to the receiving resonator 510, and the time when Tx1 is not generating an electric field. When the receiving capacitor electrode 526 overlaps and is completely aligned with Tx1 or Tx2, the input impedance is about 380Ω. As the receiving capacitor electrode 526 moves away from Tx1 or Tx2, the input impedance decreases. At a distance of 180 mm, the receiving capacitor electrode 526 is located at the center between Tx1 and Tx2, and the input impedance is 120Ω. In an embodiment, this value can be a threshold impedance. Therefore, when any capacitor electrode 2006 is presented with an impedance of 120Ω or greater, as described above, the specific capacitor electrode 2006 resonates with the inductor.

[0163] Although a particular wireless power transfer system 500 has been described, those skilled in the art will appreciate that other configurations are possible. Fig. 22 and Fig.23 Another embodiment of a portion of a wireless power transfer system is shown and is generally identified by reference numeral 2300. Wireless power transfer system 2300 is identical to wireless power transfer system 500 unless otherwise noted.

[0164] In an embodiment, the transmit resonator includes a capacitive electrode 2306 in a grid pattern, where N (the number of columns in the grid) is 7 and M (the number of rows in the grid) is 2. In this embodiment, the capacitive electrode 2306 is a rectangular plate electrode. In this embodiment, the transmit resonator also includes a transmit passive electrode 2320. Unless otherwise specified, the transmit passive electrode 2320 is the same as the passive electrode 420. The receive resonator includes two capacitive electrodes 2326. The receiver also includes a receive passive electrode 2330. Unless otherwise specified, the receive passive electrode 2330 is the same as the receive passive electrode 530.

[0165] Fig.24Another embodiment of a portion of a wireless power transfer system is shown and is generally identified by reference numeral 2400. Wireless power transfer system 2400 is identical to wireless power transfer system 2300 unless otherwise noted.

[0166] In this embodiment, the transmit resonator includes a capacitive electrode 2406 in a grid pattern, where N (the number of columns in the grid) is 1 and M (the number of rows in the grid) is 2. In this embodiment, the capacitive electrode 2406 is a rectangular plate electrode. In this embodiment, the transmit resonator also includes a transmit passive electrode 2420. Unless otherwise specified, the transmit passive electrode 2420 is the same as the passive electrode 420. The receive resonator includes two capacitive electrodes 2426. The receiver also includes a receive passive electrode 2430. Unless otherwise specified, the receive passive electrode 2430 is the same as the receive passive electrode 530.

[0167] The wireless power transmission systems 2300 and 2400 were simulated. In this embodiment, each capacitor electrode 2306 of the transmitting resonator has a length of 330 mm and a width of 100 mm. The gap between the long sides of the capacitor electrode 2306 of the transmitting resonator is 50 mm. The gap between the short sides of the capacitor electrode 2306 is 30 mm. The length of each receiving capacitor electrode 2326 is 330 mm and the width is 100 mm. The gap between the receiving capacitor electrodes 2326 is 50 mm. The gap between the capacitor electrode 2306 of the transmitting resonator and the receiving capacitor electrode 2326 is 25 mm. The gap between the capacitor electrode 2306 of the transmitting resonator and the transmitting passive electrode 2320 is 25 mm. The gap between the receiving capacitor electrode 2326 and the receiving passive electrode 2330 is 25 mm. The wireless power transmission system 2300 transmits 45 watts of power.

[0168] In an embodiment, each capacitor electrode 2406 has a length of 2490 mm and a width of 100 mm. The gap between the capacitor electrodes 2406 is 50 mm. Each receiving capacitor electrode 2426 has a length of 330 mm and a width of 100 mm. The gap between the receiving capacitor electrodes 2426 is 50 mm. The gap between the capacitor electrode 2406 of the transmitting resonator and the receiving capacitor electrode 2426 is 25 mm. The gap between the capacitor electrode 2406 of the transmitting resonator and the transmitting passive electrode 2420 is 25 mm. The gap between the receiving capacitor electrode 2426 and the receiving passive electrode 2430 is 25 mm. The wireless power transmission system 2400 transmits 45 watts of power.

[0169] The simulation results are as follows Fig.25 shown. Fig.25is a graph of the SAR (in W / kg) for a human foot with an average mass of 10 grams located 10 mm above and 10 mm from the transmit resonator. During the simulation, the receive capacitor electrode 2326 was initially aligned with the two capacitor electrodes 2306 of the transmit resonator, as Fig. 22 As shown. Configured in Fig.25 Then, the receiving capacitor electrode 2326 moves toward the other two capacitor electrodes 2306 of the transmitting resonator until the receiving capacitor electrode 2326 is located between two sets of adjacent capacitor electrodes 2306 of the transmitting resonator, as shown in FIG. Fig.23 This configuration is shown in Fig.25 The wireless power transmission system 2400 is marked as "Segment Tx-Unaligned". Fig.25 The International Commission on Non-Ionizing Radiation Protection (ICNIRP) RF exposure limits are Fig.25 Labeled as “ICNIRP RF exposure limits”.

[0170] like Fig.25 As shown, when the receiving capacitor electrode 2326 is aligned with the capacitor electrode 2306 of the transmitting resonator, the SAR of the wireless power transfer system 2300 is well below the ICNIRP RF exposure limit at a distance between 1 mm and 50 mm. Similarly, when the receiving capacitor electrode 2326 is not overlapped and aligned with the capacitor electrode 2306 of the transmitting resonator, the SAR of the wireless power transfer system 2300 is still below the ICNIRP RF exposure limit at a distance between 1 mm and 50 mm. When the distance is less than about 9 mm, the SAR of the wireless power transfer system 2400 is not less than the ICNIRP RF exposure limit. Clearly, the wireless power transfer system 2300 produces a reduced SAR, thereby providing a generally safer wireless power transfer system.

[0171] Although the specific operation of the first detector 308 and the controller 310 has been described, it will be appreciated by those skilled in the art that variations are possible. In one embodiment, the controller 310 requests the impedance presented to the capacitive electrode 306 from the first detector 308. In response to the request from the controller 310, the first detector 308 sends the impedance presented to the capacitive electrode 306 to the controller 310. Other embodiments of the first detector and controller discussed herein may operate similarly. The embodiments of the second detector discussed herein may also operate similarly.

[0172] Although the specific operation of the first detector 308 and the controller 310 has been described, it will be appreciated by those skilled in the art that variations are possible. In one embodiment, the controller 310 requests the impedance presented to a specific capacitive electrode 306 from the first detector 308. In response to the request from the controller 310, the first detector 308 sends the impedance presented to the specific capacitive electrode 306 to the controller 310. The controller 310 may issue multiple impedance requests over a period of time. The controller 310 may request the impedance presented to more than one capacitive electrode 306. Other embodiments of the first detector and controller discussed herein may operate similarly. The embodiments of the second detector discussed herein may also operate similarly.

[0173] Although specific first detectors 308 and 408 have been described, it will be appreciated by those skilled in the art that other configurations are also possible. In another embodiment, a single circuit is configured to apply current and measure voltage. In another embodiment, first detectors 308 and 408 include multiple circuits. In another embodiment, first detectors 308 and 408 are configured to detect the impedance difference between electrodes 306 and 406, respectively. In another embodiment, first detectors 308 and 408 are configured to determine the impedance presented at each electrode 306 and 406, respectively, and determine the impedance difference between electrodes 306 and 406, respectively.

[0174] Although a specific second detector 412 has been described, those skilled in the art will appreciate that other configurations are possible. In another embodiment, a single circuit is configured to apply current and measure voltage. In another embodiment, the second detector 412 includes multiple circuits.

[0175] Although specific electrodes have been described, those skilled in the art will appreciate that other configurations are possible, including but not limited to electrodes that are concentric, coplanar, circular, elliptical, disc-shaped, etc. Other suitable electrode configurations are described in U.S. Patent No. 9,979,206 to Nyberg et al., filed on September 4, 2015, the relevant portions of which are incorporated herein by reference.

[0176] Although the receiver 510 has been described as including the rectifier 514 , those skilled in the art will appreciate that other configurations are possible. In another embodiment, the receiver 510 does not include a rectifier. In an embodiment, the load 512 is electrically connected to the receive resonator 520 .

[0177] Although embodiments have been described above and shown in the accompanying drawings, those skilled in the art will appreciate that changes and modifications may be made without departing from the scope defined by the appended claims, and that the scope of the claims should be given the broadest interpretation consistent with the specification as a whole.

Claims

1. A transmitting resonator, comprising: at least two inductors; a switching network electrically connected to the inductor; a plurality of capacitor electrodes electrically connected to the switch network; a detector communicatively coupled to the controller, the detector configured to detect impedance, the detector comprising a first detector configured to detect impedance presented to the capacitive electrode; and The controller is communicatively connected to the switch network and the detector, the controller being configured to control the switch network to connect two or more capacitive electrodes to the inductor based on the detected impedance being greater than a threshold impedance, wherein the threshold impedance is a lowest value of an impedance range that allows the transmit resonator to resonate at a resonant frequency, the inductor and the capacitive electrodes being configured to resonate at the resonant frequency to generate an electric field.

2. The transmitting resonator of claim 1, wherein the detector comprises a second detector.

3. The transmitting resonator of claim 1, wherein the detector comprises at least one circuit and a phase detector.

4. The transmitting resonator of claim 3, wherein the circuit is configured to measure impedance by applying a voltage and detecting a current. 5 . The transmitting resonator of claim 2 , wherein the second detector is configured to detect impedance during wireless power transfer.

6. The transmitting resonator of any one of claims 1 to 5, wherein the switch network is configured to electrically connect each electrode to two inductors.

7. The transmitting resonator according to any one of claims 1 to 5, having the same number of inductors as capacitor electrodes.

8. The transmitting resonator according to any one of claims 1 to 5, wherein the capacitive electrode is electrically connected to the switching network via the inductor.

9. An emitting resonator according to any one of claims 1 to 5, wherein the detector is electrically connected to the controller and / or the controller is electrically connected to the switching network.

10. The transmitting resonator according to any one of claims 1 to 5, wherein the inductor is a variable inductor.

11. The transmitting resonator of claim 10, wherein the controller is electrically connected to the variable inductor, and wherein the controller is configured to control an inductance of the variable inductor.

12. The transmitting resonator of claim 11, wherein the capacitive electrode is electrically connected to the switching network via the variable inductor.

13. The transmitting resonator according to any one of claims 1 to 5, wherein the inductor and the electrode are configured to resonate to generate the electric field, thereby transferring electric energy via electric field coupling.

14. A wireless power transmission system comprising the transmitting resonator of any one of claims 1 to 6.

15. A wireless power transmission system comprising: Transmitter, including: a power supply configured to generate a power signal; and a transmitting resonator electrically connected to the power supply, the transmitting resonator comprising: at least two transmitting inductors; a switching network electrically connected to the transmit inductor; a plurality of transmit capacitor electrodes electrically connected to the switch network; a detector communicatively coupled to the controller, the detector being configured to detect impedance, The detector includes a first detector configured to detect impedance presented to the capacitive electrode; and the controller communicatively connected to the switch network and the detector, the controller configured to control the switch network to connect two or more transmit capacitor electrodes to the transmit inductor based on the detected impedance being greater than a threshold impedance, wherein the threshold impedance is a lowest value of an impedance range that allows the transmit resonator to resonate at a resonant frequency, the transmit inductor and transmit capacitor electrodes being configured to resonate at the resonant frequency to generate an electric field; and Receiver, comprising: load; and a receiving resonator electrically connected to the load, the receiving resonator comprising: at least two receive inductors; and At least two receive capacitor electrodes are electrically connected to the receive inductor, wherein the receive inductor and the receive capacitor electrodes are configured to resonate in the generated electric field and extract electric energy via resonant electric field coupling.

16. The wireless power transmission system of claim 15, wherein the transmitter further comprises an inverter electrically connected between the power source and the transmitting resonator.

17. The wireless power transmission system according to claim 15 or 16, wherein the receiver further comprises a rectifier electrically connected between the load and the receiving resonator.

18. A method for wireless power transmission, the method comprising: detecting impedance at at least two capacitor electrodes electrically connected to the switch network; communicating the impedance at the capacitive electrode to a controller communicatively coupled to the switching network; determining, at the controller, a subset of the capacitive electrodes to be connected to at least two inductors based on an impedance at the capacitive electrodes being greater than a threshold impedance, wherein the threshold impedance is a lowest value of an impedance range that allows a transmit resonator to resonate at a resonant frequency, the inductors being electrically connected to the switch network, wherein the transmit resonator includes the subset of the capacitive electrodes and the inductors; connecting a subset of the capacitive electrodes to the inductor; and The inductor and a subset of the capacitive electrodes are resonated at a resonant frequency to generate an electric field.

19. The method of claim 18, wherein connecting the subset of the capacitive electrodes comprises sending a signal from the controller to the switch network to connect the subset of the capacitive electrodes to the inductor.

20. The method according to claim 18 or 19, further comprising: detecting impedance at the inductor; sending the impedance at the inductor to the controller; determining, at the controller, whether an impedance at the inductor is within an impedance range; and If the impedance at the inductor is not within an impedance range, a signal from the controller is sent to the switch network to disconnect all capacitive electrodes from the inductor.

21. The method of claim 20, wherein the impedance range is an impedance capable of transferring electrical energy from the capacitive electrode and the inductor via resonant electrical coupling.

22. The method according to claim 18 or 19, further comprising: resonating the inductor and capacitor electrodes of the receiver at a resonant frequency; and Electrical energy is extracted from the generated electric field via resonant electric field coupling.

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