Wireless power transfer system

Abstract

The present invention relates generally to the technological field of electrical power supply. More specifically, the present invention relates to wireless power transfer (WPT) systems, and may be applicable to various environments, including, e.g., consumer electronics, industrial automation, and electric vehicle charging. The suggested WPT system provides an improvement of the technological field of electrical power supply by reducing the alignment accuracy required for efficient electromagnetic coupling and power transfer. This enhancement, in turn, may significantly facilitate the use of WPT for mobile applications, such as electric vehicle charging.

Description

WIRELESS POWER TRANSFER SYSTEMCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Nos. 63 / 548,206, filed November 12, 2023; 63 / 548,400, filed November 14, 2023; 63 / 548,403, filed November 14, 2023; 63 / 548,404, filed November 14, 2023; 63 / 548,406, filed November 14, 2023; 63 / 548,407, filed November 14, 2023; and 63 / 600,298, filed November 17, 2023, the contents of which are all incorporated herein by reference in their entirety.FIELD OF THE INVENTION

[0002] The present invention relates generally to the technological field of electrical power supply. More specifically, the present invention relates to wireless power transfer (WPT) systems, and may be applicable to various environments, including, e.g., consumer electronics, industrial automation, and electric vehicle charging.BACKGROUND OF THE INVENTION

[0003] Wireless power transfer (WPT) techniques and systems are well established and widely applied across various technological environments. These technologies include inductive (magnetic) coupling, resonant inductive coupling, capacitive coupling, electrodynamic coupling, RF power transfer, laser power transfer (LPT), and acoustic technologies.

[0004] WPT offers numerous benefits, such as eliminating physical connectors, which enhances convenience and reliability by preventing corrosion and the intrusion of dust and moisture. However, several common challenges persist. Techniques involving electromagnetic coupling often suffer from limited range and power transfer efficiency, making them less suitable for high-power applications. Environmental factors and obstacles can interfere with the power transfer process, leading to inconsistent and unreliable performance. Additionally, high-power WPT systems must address safety concerns to ensure that the transferred energy does not pose risks to humans or other electronic devices.

[0005] A significant issue with current WPT techniques is the need for close proximity and precise alignment between the transmitter and receiver to achieve efficient power transfer. This requirement limits the flexibility and practicality of WPT systems for mobile applications. While effective for charging stationary devices, these techniques are oftenunsuitable for powering or charging mobile platforms, such as vehicles operating on land, sea, air, or space, which are characterized by their mobility. Consequently, existing solutions frequently result in intermittent and discontinuous charging, relying on multiple charging pads constrained by their physical dimensions and capable of emitting electrical or magnetic fields only within their borders, necessitating strict alignment.

[0006] Addressing these challenges is crucial for the widespread adoption and success of WPT technologies in various applications, making it an active area of research.SUMMARY OF THE INVENTION

[0007] Accordingly, there is a need for a WPT system which would provide an improvement of the technological field of electrical power supply by reducing the alignment accuracy required for efficient electromagnetic coupling and power transfer. This enhancement would, in turn, facilitate the use of WPT for mobile applications, such as electric vehicle charging.

[0008] In the general aspect, the invention may be directed to a Wireless Power Transfer (WPT) system. The WPT system may include: at least one primary transmitting antenna, comprising at least one first conducting surface connectable to an alternating power source and being adapted to receive an alternating electrical signal, at a first frequency, therefrom; and at least one primary receiving antenna, comprising at least one second conducting surface connectable to an electrical load, wherein the at least one first conducting surface, and at least one second conducting surface have matching geometric properties, defined so as to substantially cancel, in an operational mode, reactance of the WPT system at the first frequency.

[0009] In some embodiments, the operational mode may be determined by a set of conditions. The set of conditions may include the following conditions: (i) said at least one first conducting surface being in operative connection with the alternating power source and receiving the alternating electrical signal at the first frequency; (ii) said at least one second conducting surface being in operative connection with the electrical load; and (iii) said at least one primary transmitting antenna and at least one primary receiving antenna being positioned opposite each other within a near-field region thereof.

[0010] In some embodiments, the first frequency may be not substantially equal to a natural resonance frequency of a transmitting electrical circuit, that may include said at least oneprimary transmitting antenna, when said at least one primary transmitting antenna and said at least one primary receiving antenna are positioned in a far-field region thereof.

[0011] In some further embodiments, the first frequency may be not substantially equal to a natural resonance frequency of a receiving electrical circuit, that may include said at least one primary receiving antenna, when said at least one primary transmitting antenna and said at least one primary receiving antenna are positioned in a far-field region thereof.

[0012] In some embodiments, said matching geometric properties may further be defined so as to substantially avoid self-resonance of said at least one primary transmitting antenna and said at least one primary receiving antenna at the first frequency, when said at least one primary transmitting antenna and said at least one primary receiving antenna are positioned in a far-field region thereof.

[0013] In some embodiments, said matching geometric properties may be further defined so as to cause, at the first frequency, a mismatch of an impedance of said at least one primary transmitting antenna to the impedance of free space.

[0014] In some embodiments, said matching geometric properties are further defined so as to cause, at the first frequency, a mismatch of an impedance of said at least one primary receiving antenna to the impedance of free space.

[0015] In some embodiments, the near-filed region may represent a reactive near-field region which may be defined by the first frequency and said matching geometric properties.

[0016] In some embodiments, the at least one primary transmitting antenna and the at least one primary receiving antenna may be configured to be positioned opposite each other, in substantially parallel planes, within said near-field region.

[0017] In some embodiments, said matching geometric properties may further be defined so as to provide, in the operational mode, a total effective electrical length of the WPT system, substantially equal to a quarter wavelength of the first frequency or an integer product thereof.

[0018] In some embodiments, the at least one second conducting surface may include: a continuous planar spiral signal conductor; and a plate-like ground conductor. Said continuous planar spiral signal conductor and said plate-like ground conductor may be positioned substantially parallel to each other.

[0019] In some embodiments, said antennas may be devoid of auxiliary capacitive or inductive devices, or combination thereof.

[0020] In some embodiments, the at least one first conducting surface may include: a continuous signal conductor, configured to be stretched along a first path, and receive the electrical signal from said alternating power source; and at least one ground conductor, configured to be stretched along said first path, substantially parallel to the signal conductor, and being in operative communication with a ground of said alternating power source.

[0021] In some embodiments, said at least one primary receiving antenna may include a plurality of primary receiving antennas linearly spaced along said first path and may be positioned opposite the at least one first conducting surface within the near-field region. The term ‘linearly’ shall not be understood herein as limiting relative positioning of receiving antennas with respect to their order.

[0022] In some embodiments, said plurality of primary receiving antennas may include a first set of primary receiving antennas, each placed from a feed point of the continuous signal conductor at a distance equal to even integer product of a quarter wavelength of the first frequency and having geometric properties of said at least one second conducting surface thereof matching said at least one first conducting surface so as to provide, in the operational mode, an effective electrical length of the segment of the WPT system powering the electrical load connected to a respective primary receiving antenna of the first set substantially equal to even integer product of the quarter wavelength of the first frequency.

[0023] In some embodiments, said plurality of primary receiving antennas may further include a second set of primary receiving antennas, each distanced from the feed point of the continuous signal conductor at a distance equal to odd integer product of a quarter wavelength of the first frequency and having geometric properties of said at least one second conducting surface thereof matching said at least one first conducting surface so as to provide, in the operational mode, an effective electrical length of the segment of the WPT system powering the electrical load connected to a respective primary receiving antenna of the second set substantially equal to odd integer product of the quarter wavelength of the first frequency.

[0024] In some embodiments, each of said plurality of primary receiving antennas may further be configured to power a respective electrical load via: a secondary transmitting antenna, comprising at least one first mediatory signal conductor, configured to be stretched along a second path and positioned opposite the at least one second conductive surface of a respective primary receiving antenna within a near-field region thereof; and a secondaryreceiving antenna, comprising at least one second mediatory signal conductor in operative connection with the respective electrical load and positioned opposite to the at least one first mediatory signal conductor within a near-field region thereof; Said second conductive surface of the respective primary receiving antenna, the at least one first mediatory signal conductor, and the at least one second mediatory signal conductor may have geometric properties matching each other so as to provide, in the operational mode, an effective electrical length of the segment of the WPT system powering the respective electrical load substantially equal to integer product of the quarter wavelength of the first frequency.

[0025] In some embodiments, the at least one first conducting surface may further include: at least one active shielding conductor at least partially surrounding the continuous signal conductor along the length thereof in a frame-like manner and being configured to receive the electrical signal from the alternating power source; wherein said continuous signal conductor and said at least one active shielding conductor have geometric properties matching so that the at least one active shielding conductor and the continuous signal conductor are configured to generate electromagnetic fields with a predetermined phase differences so as to create, in the operational mode, a constructive interference in the direction towards the at least one primary receiving antenna and a destructive interference in the direction perpendicular thereto.

[0026] In some embodiments, the system may further include: at least one secondary transmitting antenna, including at least one first mediatory signal conductor in a direct or indirect conductive connection with the at least one primary receiving antenna; at least one secondary receiving antenna, including at least one second mediatory signal conductor in a direct or indirect conductive connection with the electrical load and positioned opposite to the at least one first mediatory signal conductor within a near-field region thereof. Said secondary transmitting antenna and said secondary receiving antenna may be separated by a separating surface; and said second conductive surface, the at least one first mediatory signal conductor, and the at least one second mediatory signal conductor may have geometric properties matching each other so as to provide, in the operational mode, a total effective electrical length of the WPT system substantially equal to a quarter wavelength of the first frequency or an integer product thereof.

[0027] In some embodiments, the at least one first conducting surface may include: a platelike signal conductor, configured to receive the electrical signal from said alternating powersource; and a plate-like ground conductor, substantially parallel to the plate-like signal conductor and being in operative communication with a ground of said alternating power source. Said matching geometric properties may be defined so as to substantially cancel, in the operational mode, reactance of the WPT system, at the first frequency, when the at least one second conducting surface is positioned between the plate-like signal conductor and the plate-like ground conductor within a near-field region thereto.

[0028] In some embodiments, the at least one first conducting surface and the at least one second conducting surface may further be configured to form, in the operational mode, an electrostatic special resonator.

[0029] In some embodiments, the system may further include: at least one feeder antenna, comprising at least one feeding signal conductor in a direct or indirect conductive connection with the alternating power source and positioned opposite to the at least one first conducting surface within a near-field region thereof. Said at least one primary transmitting antenna may be powered via said at least one feeder antenna; and said at least one feeding signal conductor, the at least one first conducting surface, and at least one second conducting surface may have geometric properties matching each other so as to provide, in the operational mode, a total effective electrical length of the WPT system substantially equal to a quarter wavelength of the first frequency or an integer product thereof.

[0030] In some embodiments, the WPT system may further include a complementary conducting surface, adapted to be positioned, in the operational mode, between, and substantially parallel to the at least one first conducting surface and at least one second conducting surface.

[0031] In some embodiments, the alternating power source may be adapted to generate the alternating electrical signal at a second, predetermined frequency, and the complementary conducting surface may have geometric properties that match those of the at least one first conducting surface and at least one second conducting surface, so as to substantially cancel, in the operational mode, reactance of the WPT system, at the second frequency.

[0032] In some embodiments, said geometric properties of the complementary conductive surface may be defined so as to provide, in the operational mode, a total effective electrical length of the WPT system, when the complementary conducting surface is positioned between, and substantially parallel to the at least one first conducting surface and at least onesecond conducting surface within the near-field region therebetween, substantially equal to a quarter wavelength of the second frequency or an integer product thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to organization and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:

[0034] Fig. 1 illustrates a top view of WPT system transmitting antenna and the parameters thereof, according to some embodiments;

[0035] Fig. 2 illustrates a top view of the transmitting antenna and the receiving antenna of the WPT system, according to some embodiments;

[0036] Fig. 3A illustrates a bottom view of the receiving antenna of the WPT system, according to some embodiments;

[0037] Fig. 3B illustrates a side view of the receiving antenna of the WPT system, according to some embodiments;

[0038] Fig. 4A illustrates a bottom view of the continuous planar spiral signal conductor of the receiving antenna and the parameters thereof, according to some embodiments;

[0039] Fig. 4B illustrates a side view of the continuous planar spiral signal conductor of the receiving antenna and the parameters thereof, according to some embodiments;

[0040] Figs. 4C-4D illustrate a bottom view of the receiving antenna of the WPT system, showing parameters of the plate-like ground conductor, according to some embodiments;

[0041] Figs. 4E-4F illustrate a side view of the receiving antenna of the WPT system, showing parameters thereof, according to some embodiments;

[0042] Figs. 5A-5G illustrate side and bottom views of the receiving antenna of the WPT system, according to some alternative embodiments;

[0043] Figs. 6A-6B illustrate a top view of the WPT system showing different lengths of the conducting surface of the transmitting antenna, while having the same configuration of the receiving antenna.

[0044] Figs. 7A-7B illustrate a side view of the WPT system, showing coupling and wireless power transfer, with different lengths of the conducting surface of the transmitting antenna,while having the same configuration of the receiving antenna, according to some embodiments.

[0045] Figs. 8A-8B illustrate a side view of the WPT system, showing simultaneous coupling and wireless power transfer, with different lengths of the conducting surface of the transmitting antenna, while having multiple receiving antennas of the same configuration, according to some embodiments.

[0046] Figs. 9A-9G illustrate different views of the complementary conducting surface of the WPT system, and parameters thereof, according to some embodiments.

[0047] Fig. 10A illustrates a top view of the complementary conducting surface positioned above the transmitting antenna, according to some embodiments.

[0048] Fig. 10B illustrates a top view of the WPT system having complementary conducting surface positioned between the transmitting antenna and the receiving antenna, according to some embodiments.

[0049] Fig. 11 illustrates a side view of the WPT system, showing coupling and wireless power transfer using the complementary conductive surface, according to some embodiments.

[0050] Fig.12 illustrates a side view of the WPT system, showing simultaneous coupling and wireless power transfer to multiple receiving antennas, using the complementary conductive surface, according to some embodiments.

[0051] Fig.l3A illustrates a side view of the WPT system, showing coupling and wireless power transfer to the receiving antennas, while having transmitting antenna powered via the feeder antenna, according to some embodiments.

[0052] Fig.l3B illustrates a side view of the WPT system, showing simultaneous coupling and wireless power transfer to multiple receiving antennas, while having transmitting antenna powered via the feeder antenna, according to some embodiments.

[0053] Fig. 14A illustrates a top view of the WPT system, having a plurality of primary receiving antennas linearly spaced along the length of the primary transmitting antenna, according to some embodiments;

[0054] Fig. 14B illustrates a top view of the WPT system, having a plurality of primary receiving antennas linearly spaced along the length of the primary transmitting antenna, and coupled with respective secondary transmitting antennas and secondary receiving antennas, according to some embodiments;

[0055] Figs. 15A-15D illustrate isometric views of various configurations of receiving antenna, according to some alternative embodiments;

[0056] Fig. 16 illustrates a side view of the secondary transmitting antenna and secondary receiving antenna, showing EM coupling therebetween, according to some embodiments;

[0057] Fig. 17A illustrates a side view of the secondary transmitting antenna and secondary receiving antenna separated by a separating surface, according to some embodiments;

[0058] Fig. 17B illustrates a schematic view of the receiving circuit having primary receiving antenna, secondary transmitting antenna and secondary receiving antenna separated by the separating surface, according to some embodiments;

[0059] Figs. 18A-18B illustrate schematic isometric views of a WPT system, wherein transmitting antenna includes two conducting plates and a plurality of receiving antennas is positioned therebetween;

[0060] Figs. 19A-19B illustrate aspects of EM field distribution in the operational mode of the WPT system, according to some embodiments;

[0061] Figs. 20A-20C illustrate a configuration of the WPT system having shielding conductor for mitigation of the undesired EM field distribution, according to some embodiments;

[0062] Figs. 21A-21F illustrate aspects of an equivalent electrical circuit of the WPT system, according to some embodiments of the present invention.

[0063] It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0064] One skilled in the art will realize the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting of the invention described herein. Scope of the invention is thus indicated by the appended claims, rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

[0065] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, and components have not been described in detail so as not to obscure the present invention. Some features or elements described with respect to one embodiment may be combined with features or elements described with respect to other embodiments. For the sake of clarity, discussion of same or similar features or elements may not be repeated.

[0066] Although embodiments of the invention are not limited in this regard, the terms “plurality” and “a plurality” as used herein may include, for example, “multiple” or “two or more”. The terms “plurality” or “a plurality” may be used throughout the specification to describe two or more components, devices, elements, units, parameters, or the like. The term “set” when used herein may include one or more items.

[0067] It shall be understood that, in the context of this description, terms like ‘mobile,’ ‘mobile applications,’ and similar should not be confused with the application of WPT for mobile devices such as smartphones and tablets. Although the suggested WPT system may also be applicable for such scenarios and is not limited in this regard, the term ‘mobile’ is primarily used here to indicate ‘movable’ or ‘non- stationary’ use cases, such as WPT for vehicles.

[0068] It shall be understood that, in the context of present invention, terms like ‘geometric properties’, ‘dimension’, ‘dimension parameters’ and similar refer to geometrical definition of the shape of conducting surfaces (conductors) of antennas and their interposition. Hence, in the context of the present invention, these terms shall be considered equivalent.

[0069] In the present disclosure, various aspects of the suggested WPT system are discussed under the condition of system being in the ‘operational mode’. It shall be understood that said ‘operational mode’ may be determined by a set of conditions including: (i) conducting surface of transmitting antenna being in operative connection with the alternating power source and receiving the alternating electrical signal at the first frequency (e.g., a signal conductor of the transmitting antenna being connected to the alternating power source to receive the electrical signal therefrom and a ground conductor of the transmitting antenna being connected to the ground of the alternating power source); (ii) the conducting surface of the receiving antenna being in operative connection with the electrical load (e.g., a signalconductor of the receiving antenna being connected to the load and a ground conductor of the receiving antenna being connected to the ground of the receiving circuit); and (iii) the transmitting antenna and the receiving antenna being positioned opposite each other within a near-field region thereof (e.g., reactive near-field region).

[0070] It shall be understood that, in the context of the present invention, the terms ‘charging area’, ‘powering area’ and similar refer to the area in the plane of the transmitting antenna, where the electromagnetic coupling can be achieved, also may be referred as ‘aperture’ or ‘effective area’ of the transmitting antenna or the receiving antenna. Terms like ‘charging volume’, ‘powering volume’ and similar refer to the geometrical volume defined by the effective areas of the receiving and transmitting antennas and the distance therebetween. It should be understood that these ‘charging area’ and ‘charging volume’ terms apply only when the WPT system is in operational mode. Therefore, whenever these terms are mentioned in this disclosure, the WPT system is considered to be in operational mode.

[0071] In the context of the present disclosure, the term ‘impedance of free space’ shall be understood as a physical constant that relates the magnitudes of the electric and magnetic fields of electromagnetic radiation traveling through free space. As known, impedance of free space equals approximately 376.73 ohms.

[0072] It shall be understood that, in the context of the present description, such terms as ‘transmitting antenna’, ‘primary transmitting antenna’, ‘secondary transmitting antenna’ and similar may refer to the antenna of the same configuration, hence, in some respects may be considered equivalent. Terms ‘primary’ and ‘secondary’ are used herein only to differentiate between the elements of the WPT system including plurality thereof, for the reason of clarity.

[0073] It shall be understood that, in the context of the present description, such terms as ‘receiving antenna’, ‘primary receiving antenna’, ‘secondary receiving antenna’ and similar may refer to the antenna of the same configuration, hence, in some respects may be considered equivalent. Terms ‘primary’ and ‘secondary’ are used herein only to differentiate between the elements of the WPT system including plurality thereof, for the reason of clarity.

[0074] It shall be understood that, in the context of the present disclosure, such terms as ‘complementary surface’ and ‘complementary conducting surface’ may refer to the same element and, therefore, may be considered equivalent. Additionally, such terms as‘supporting plate’, ‘supporting plane’ (or, in some contexts, ‘plate’ and ‘plane’) may refer to the same element and, therefore, may be considered equivalent.

[0075] It shall further be understood that, in the context of the present disclosure, terms ‘transmitting’ and ‘receiving’ relate to the function of respective elements (e.g., antennas or circuits) with respect to the direction of power transmission. However, it shall be understood that, in some embodiments, the suggested the WPT system may be configured to operate in reverse mode, or may have a reversed structure, where ‘receiving’ antenna operates as ‘transmitting’ antenna, and ‘transmitting’ antenna operates as ‘receiving’ antenna. It shall further be understood that, in such ‘reverse’ configuration, electrical load may be connected to antenna having ‘transmitting’ configuration, as referred herein, and the alternating power source may be connected to antenna having ‘receiving’ configuration, as referred herein.

[0076] It shall be understood that, in the context of the present invention, the terms ‘receiver’, receiving circuit’ and ‘receiving module’ refer to an electrical circuit, at the ‘receiving’ side, including at least one receiving antenna and an electrical load (e.g., rechargeable battery), but may also include any other components. The present invention shall not be considered limited to any specific configuration of the receiving circuit, as long as it is used for powering the electrical load. Hence, in the context of the present invention, the terms like ‘receiver’, receiving circuit’, ‘receiving module’ and similar shall be considered equivalent.

[0077] It shall be understood that, in the context of the present invention, the terms ‘transmitter’, transmitting circuit’ and ‘transmitting module’ refer to an electrical circuit, at the ‘transmitting’ side, including at least one transmitting antenna and being connectable or including an alternating power source. In some embodiments, the transmitting circuit may also include any other components. The present invention shall not be considered limited to any specific configuration of the transmitting circuit, as long as it is used for receiving an electrical signal from the alternating power source and for powering transmitting antenna with this signal. Hence, in the context of the present invention, the terms like ‘transmitter’, transmitting circuit’, ‘transmitting module’ and similar shall be considered equivalent.

[0078] It shall be understood that the present invention and any of embodiments provided herein are not limited in respect of the sequence of transmitting-receiving antennas. In other words, although in some embodiments, only one pair of transmitting and receiving antennas is discussed, the claimed system may have another transmitting antenna coupled to thereceiving antenna of the pair, and another receiving antenna coupled to the added transmitting antenna and so on, as long as the general conditioning for achieving the desired resonance remains, meaning that all the antennas of the sequence (and conducting elements thereof) have geometric properties such that, when matched, the reactance of the obtained circuit of the WPT system is substantially cancelled.

[0079] It shall further be understood that the suggested system is not limited to any specific configuration of receiving or transmitting antennas. The specific configuration of transmitting and receiving antennas shown in some embodiments in the present description is provided as a non-exclusive example only. Accordingly, in some embodiments, transmitting antennas may have the same structure as receiving antennas demonstrated herein. In some further embodiments, receiving antennas may have the same structure as transmitting antennas demonstrated herein. Accordingly, receiving and transmitting antennas may have similar configuration, furthermore, any configuration described herein.

[0080] Unless explicitly stated, the method embodiments described herein are not constrained to a particular order or sequence. Additionally, some of the described method embodiments or elements thereof can occur or be performed simultaneously, at the same point in time, concurrently, or iteratively and repeatedly.

[0081] As known, the efficiency of the WPT system strongly depends on the impedance matching between the transmitter and the receiver. When the impedances of the transmitter and receiver are matched, it ensures that the maximum amount of power is transferred from the transmitter to the receiver with minimal loss. Impedance mismatches, in turn, can cause reflections of the signal, leading to power loss and reduced efficiency.

[0082] In practical terms, matching the impedances of the receiver and the transmitter helps to minimize signal reflections and ensures that the transmitted power is effectively received and utilized by the receiver.

[0083] As is commonly understood, impedance in an electrical circuit is composed of three main components: resistance (R), inductance (L), and capacitance (C). Each of these components contributes uniquely to the total impedance of the circuit. Impedance matching involves ensuring that the impedance of the source (transmitter) and the load (receiver) are equal or complementary. Specifically, in the ideal scenario, the inductive reactance should be matched or countered by capacitive reactance in the load; the capacitive reactance should be matched or countered by inductive reactance in the load; and the resistance should beequal between the source and load for maximum power transfer. System 200 may achieve any impedance matching, which may be pure ohmic or complex.

[0084] Traditionally, impedance matching is achieved using additional, auxiliary capacitive, inductive devices, or combination thereof, sometimes called ‘matching circuits’ or ‘compensation circuits’. Such matching circuits consist of inductive and capacitive components connected in parallel and series, providing abovementioned impedance matching conditions.

[0085] The major drawback of the solutions of the prior art is their efficiency, which is highly dependent on the precise alignment of the receiving and transmitting antennas, limiting their use in movable environments.

[0086] As known, each electrical circuit (such as a transmitting circuit and a receiving circuit of the WPT system) is characterized by its effective electrical length, which is a dimensionless parameter equal to the physical length of an electrical conductor (such as a cable, wire, or conducting surface of an antenna), divided by the wavelength of alternating current at a given frequency traveling through the conductor.

[0087] In order to achieve maximal energy transfer efficiency, it is critical in known solutions that both the receiver and transmitter are each tuned to the same resonance frequency. Obviously, this frequency depends on the electrical length of each circuit, which is influenced by the presence of capacitive and inductive components. To tune the resonant frequency, ‘electrical lengthening’ and ‘electrical shortening’ are performed by adding inductive and / or capacitive components, respectively.

[0088] In contrast to the aforementioned approach, the following is suggested: since both the transmitting and receiving antennas affect the mutual reactance and capacitance of the WPT system when their antennas are positioned close to each other in the near-field region (e.g., the reactive near-field portion), it is possible to achieve the desired resonant condition of the entire circuit of the WPT system without using any auxiliary components, given the matching geometric parameters of the antennas.

[0089] When the WPT system is in operational mode, meaning that the transmitting circuit is electromagnetically coupled with the receiving circuit, the WPT system represents a single electrical circuit. The resonance condition of the obtained electrical circuit is defined by its total effective electrical length. Considering the electrical circuit of the WPT system, in the operational mode, as a whole, geometric parameters of each conducting element (such asreceiving or transmitting antenna) of the circuit (e.g., of the receiving circuit and the transmitting circuit) obviously contribute to the reactance of the entire circuit. Accordingly, it is suggested herein that the mutual reactance of the system may be cancelled using matching geometric properties of the conducting surfaces of the receiving antenna and the transmitting antenna, as a result of a mutual influence of the antennas when placed opposite in the near-field region.

[0090] To get such a result, it is further suggested to define these matching geometric properties so as to provide, in the operational mode, a total effective electrical length of the WPT system (of the entire circuit), substantially equal to a quarter wavelength of the frequency of the alternating power source, or an integer product thereof.

[0091] As a result, the suggested WPT system is not only devoid of auxiliary devices, but also provides significant benefits regarding positioning accuracy and alignment limitations, opening new perspectives for mobile applications.

[0092] Reference is now made to Fig. 1, showing a top view of WPT system transmitting antenna 100 and the parameters (dimensions) thereof, according to some embodiments.

[0093] In some embodiments, WPT system comprises at least one primary transmitting antenna 100, including at least one conducting surface (also referred herein as ‘first’ conducting surface) connectable to an alternating power source and being adapted to receive an alternating electrical signal, at a first frequency.

[0094] In some particular embodiments, said at least one conducting surface of the primary transmitting antenna 100 includes continuous signal conductor 101, configured to be stretched along a path (also referred herein as ‘first’ path), and receive the electrical signal from said alternating power source. Said at least one conducting surface of primary transmitting antenna 100 may further include at least one ground conductor (e.g., ground conductor 102A and / or 102B), configured to be stretched along the same path, as signal conductor 101, substantially parallel thereto, and being in operative communication with a ground of said alternating power source.

[0095] As shown in Fig. 1, signal conductor 101 and ground conductors 102A and 102B of transmitting antenna 100 are characterized by a plurality of geometric properties (also referred herein as dimension parameters). The dimension parameters of signal conductor 101 and ground conductors 102 A and 102B will determine the covered charging and powering area (the area in the plane of the transmitting antenna, where the electromagneticcoupling can be achieved, also may be referred as ‘aperture’ or ‘effective area’ of the transmitting antenna, such as antenna 100), the covered charging and powering volume (the geometrical volume defined by an effective area of the receiving antenna, effective area of the transmitting antenna and the distance therebetween), the field line distribution and so for a given frequency (e.g., said first frequency), and vice versa. In some embodiments, said geometrical properties may include:

[0096] Wf- signal conductor 101 width;

[0097] Lf- signal conductor 101 length;

[0098] Tf- signal conductor 101 thickness;

[0099] Wgl - ground conductor 102A width;

[0100] Lgl - ground conductor 102 A length;

[0101] Tgl - ground conductor 102A thickness;

[0102] Wg2 - ground conductor 102B width;

[0103] Lg2 - ground conductor 102B length;

[0104] Tg2 - ground conductor 102B thickness;

[0105] D1.1-D1.N - the distance between signal conductor 101 and ground conductor 102 A at different points along their length;

[0106] D2.1-D2.N - the distance between signal conductor 101 and ground conductor 102B at different points along their length;

[0107] Hr el 1.1 -Hr el 1. N - the relative height between signal conductor 101 and ground conductor 102 A at different points along their length;

[0108] Hrel2.1-Hrel2.N - the relative height between signal conductor 101 and ground conductor 102B.

[0109] In the operational mode, these geometric parameters may further define the following characteristics of the WPT system:

[0110] Z1.1-Z1.N - the impedance between signal conductor 101 and ground conductor 102A;

[0111] Z2.1-Z2.N - the impedance between signal conductor 101 and ground conductor 102B.

[0112] Reference is now made to Fig. 2, schematically showing a top view of transmitting antenna 100 and receiving antenna 210 of WPT system 200, according to some embodiments. Receiving antenna 210 has an effective area such that when it is located withinthe charging area determined by transmitting antenna 100 it is influenced by signal conductor 101 and ground conductor 102 (such as conductor 102A and 102B of Fig. 1) of transmitting antenna 100, enabling strong electromagnetic coupling. As shown, transmitting antenna 100 may be characterized by length LI. Conductors 101 and 102 may be stretched along the path P and be positioned substantially parallel to one another.

[0113] In some embodiments, effective area of receiving antenna 210 may fully overlap, partially overlap, or not overlap effective areas of conductors 101 and 102, wherein in the latter scenario the effective area of receiving antenna 210 is positioned substantially between the effective areas of conductors 101 and 102.

[0114] Reference is now made to Figs. 3A and 3B, showing bottom and side views of receiving antenna 210 of WPT system 200, according to some embodiments.

[0115] In some embodiments, receiving antenna 210 of WPT system 200 may include at least one conducting surface (also referred herein as ‘second’ conducting surface) connectable to an electrical load. In particular, in some embodiments, receiving antenna 210 may include continuous planar spiral signal conductor 211 and plate-like ground conductor 212. In some embodiments, continuous planar spiral signal conductor 211 and plate-like ground conductor 212 may be positioned substantially parallel to each other (as shown in Fig. 3B). Conductors 211 and 212 may be connectable to the electrical load.

[0116] Reference is now made to Figs. 4A-4F, illustrating bottom and side views of planar spiral signal conductor 211 and plate-like ground conductor 212 of receiving antenna 210 and the parameters thereof, according to some embodiments.

[0117] As can be seen in Figs.4A and 4B, the parameters (geometric properties) of signal conductor 211 may include length, width, and thickness of each conductor segment (Ln, Wn, Tn), relative angle (am) and distance (Dacp) of adjacent conductor segments. The parameters may further include distance along the area of conductor 211 (Dcpl - DcpZn) in relation to a predefined plane (e.g., plane of transmitting antenna 100).

[0118] As can be seen in Figs. 4C-4F, the parameters (geometric properties) of ground conductor 212 may include length, width and thickness (Lg, Wg, Tg) of ground conductor 212. The parameters of relative positioning of signal conductor 211 to ground conductor 212 may include relative angle (P) between them, vertical distance (DagZ) between them, planar distance between conductors 211 and 212 along their areas (DcgXl-DcgXk and DcgYl- DcgYk) and planar offset (OSagX and OSagY) of ground conductor 212 with respect to signalconductor 211. In some embodiments, ground conductor 211 and signal conductor 212 may be placed and separated with dielectric material for adjusting the impedance between them.

[0119] Depending on specific embodiments, an input RF power port which transfers the receiving power from receiving antenna 210 to the load via the receiving unit and rectifier (not shown) may be connected to any place on any conductor segment of signal conductor 211 and ground conductor 212 of receiving antenna 210.

[0120] It shall be understood that, by designing transmitting antenna 100 and receiving antenna 210 with specific values of the abovementioned geometric parameters (shown in Figs. 1, 4A-4F), such inductance / capacitance characteristics of transmitting antenna 100 and receiving antenna 210 (and, accordingly, of the entire transmitting circuit and receiving circuit) may be achieved, that when in operational mode, reactance of system 200 may be cancelled, thereby providing for the resonance conditions. In other words, geometric parameters, shown in Figs. 1 and 4A-4F, may be selected so as to provide, in the operational mode, a total effective electrical length of WPT system 200 (of the entire circuit thereof), substantially equal to a quarter wavelength of the frequency of the alternating power source (also referred herein as ‘first’ frequency), or an integer product thereof, thereby allowing system 200 to resonate at this frequency.

[0121] Reference is now made to Figs. 5A-5G illustrating side and bottom views of the receiving antenna of the WPT system, according to some alternative embodiments.

[0122] As shown in Fig. 5A, the structure of signal conductor 211 can have various shapes and forms. E.g., in some embodiments, conductor 211, at least at some segments, may have a non- spiral shape.

[0123] Figs. 5B-5C present two embodiments of a receiving antenna 210 having a narrow structure. The embodiments of Fig. 5B is narrow in the X direction and the embodiment of Fig. 5C is narrow in the Y direction.

[0124] Figs. 5D-5E illustrate yet another embodiment, where the relative position between signal conductor 211 and ground conductor 212 of receiving antenna 210 can be changed, adjust, set, etc. to create the resonance condition at predefined frequency with transmitting antenna 100, in the operational mode (e.g., when positioned within the designated and predefined charging volume of the WPT system, e.g., when positioned opposite each other within the near-field region).

[0125] Figs. 5F-5G illustrate other alternative embodiments of receiving antenna 210. As shown in Fig. 5F, ground conductor 212 may have a frame shape not covering signal conductor 211 in the center area. Fig. 5G shows yet another embodiment of the present invention where ground conductor 212 has a narrow, elongated structure having significantly smaller area than signal conductor 211 and covering it partially.

[0126] It shall be appreciated that all the embodiments of transmitting antenna 100 and receiving antenna 210, involving aspects of the shape, structure, geometrical properties etc. of signal conductors 101, 211 and ground conductors 102, 212, as well as positioning of any one of these elements with respect to another element, are demonstrated herein for the purpose of clarity, and shall not be considered exclusive. It shall be understood that, depending on embodiments, antennas (e.g., transmitting antenna 100, receiving antenna 210 etc.) may be, e.g., electrically short, electrically long, open-circuited, short-circuited, can reflect any impedance etc. It should further be understood that, in some embodiments, transmitting antenna 100, receiving antenna 210 and elements thereof may have different structure, shape, dimensions, relative positioning, alignment etc., than illustrated in the accompanied figures, thereby significantly varying in geometric properties. However, according to the concept of the present invention, despite these variations, their geometric properties should be selected to match so as to substantially cancel, in the operational mode, reactance of WPT system 200 at the desired frequency of the alternating power source. In other words, regardless of possible variations of geometric properties of transmitting antenna 100, receiving antenna 210 and elements thereof, their geometric properties should be selected to match so as to provide, in the operational mode, a total effective electrical length of WPT system 200, substantially equal to a quarter wavelength of the frequency of the power source or an integer product thereof, thereby providing for the desired resonance condition. According to some embodiments, receiving antenna 210 described herein may have surface support plate (not shown) between signal conductor 211 and ground conductor 212. According to some embodiments, the surface support plate may be made of a dielectric material.

[0127] Reference is now made to Figs. 6A-6B illustrating a top view of WPT system 200 showing different lengths of the conducting surface of transmitting antenna 100 (of conductors 101 and 102 thereof), while having the same configuration of the receiving antenna. As can be seen in Fig. 6A, conductors 101 and 102 of transmitting antenna 100have length LI, and, in Fig. 6B, conductors 101 and 102 have length L2, wherein L2 is substantially longer than LI.

[0128] It shall be understood that, according to the concept of the present invention, transmitting antenna may significantly vary in length, while providing for substantially equal resonance conditions in multiple locations along its length, and, in some embodiments, across the length thereof. In other words, receiving antenna 210 may be moved along the length of transmitting antenna 100 (e.g., along and across the direction P) while maintaining strong electromagnetic coupling therewith. This is possible because, as indicated above, resonance occurs when the total effective electrical length of WPT system 200, is substantially equal to a quarter wavelength of the frequency of the power source or an integer product thereof. When receiving antenna 210 is being moved along the length (and, in some embodiments, across the length thereof) of transmitting antenna 100, total effective electrical length changes as the distance of the region of electromagnetic coupling from the feed point of transmitting antenna 100 increases. Accordingly, there may be multiple locations along the length of transmitting antenna 100, where the total effective electrical length equals different integer products of the quarter wavelength of the frequency of the power source (i.e., Effective Electrical Length = n * A / 4, where A is the frequency wavelength of the power source signal (also referred herein as ‘first’ frequency) and n G IV).

[0129] It shall be understood that, in some embodiments, the wavelength may be selected so, that the entire length of the transmitting antenna provides an area for desired resonance condition (e.g., when the antenna is electrically shorter than the quarter of the wavelength of the signal of the ‘first’ frequency, received from the power source).

[0130] The abovementioned benefit is critically important, as it makes the suggested WPT system applicable for charging and powering one or more in-motion mobile platforms, such as locomotor devices, electric vehicles (including public transportation, aerial vehicles, electric scooters, etc.), hybrid vehicles, robots (including warehouse robots, agriculture robots etc.), smart warehouse transportation, etc. The system may be applied for any type of locomotor / vehicle, either autonomous or controllable, configured to be operatable above, on or under the ground, above or under water, in air, space etc.

[0131] Reference is now made to Figs. 7A-7B, illustrating a side view of the WPT system, showing coupling and wireless power transfer, with different lengths of the conducting surface of the transmitting antenna, while having the same configuration of thereceiving antenna, according to some embodiments. As explained with reference to Figs. 6A-6B above, WPT system 200 maintains resonance condition and effective power transfer at the predefined frequency of the power source, in multiple positions of receiving antenna 210 along the length of transmitting antenna 100. In other words, system 200 (as shown in Figs. 7A-7B, may resonate at the same frequency and hold substantially same coupling coefficients and wireless power transfer efficiency for both transmitting antenna lengths of LI and L2 with the receiving antenna 210 of the same design along and across direction P within the charging volume.

[0132] According to some embodiments of the present invention, said resonance occurs only when receiving antenna 210 is present within the predefined charging volume, meaning that receiving antenna 210 and transmitting antenna 100 should be positioned at a predefined distance with respect to each other (e.g., in the near-field region).

[0133] To achieve that, in some embodiments, the desired frequency of the power source (also referred herein as ‘first’ frequency), that provides resonance condition for the system in the operational mode, may be selected (defined) different (not substantially equal) to a natural resonance frequency of the transmitting electrical circuit (e.g., circuit including transmitting antenna 100 and, e.g., the alternating power source), i.e., the frequency that allows self-resonance of the transmitting electrical circuit when transmitting antenna 100 and receiving antenna 210 are positioned in a far-field region thereof.

[0134] Furthermore, in some embodiments, the desired frequency of the power source (also referred herein as ‘first’ frequency), that provides resonance condition for the system in the operational mode, may be selected (defined) different (not substantially equal) to a natural resonance frequency of the receiving electrical circuit (e.g., circuit including receiving antenna 210 and, e.g., the electrical load), i.e., the frequency that allows selfresonance of the receiving electrical circuit when transmitting antenna 100 and receiving antenna 210 are positioned in a far-field region thereof.

[0135] In other words, in some embodiments, said matching geometric properties of receiving antenna 210 and transmitting antenna 100 are selected (defined) so as to substantially avoid self-resonance of transmitting antenna 210 and receiving antenna 100 at the frequency of the power source, when transmitting antenna 100 and receiving antenna 210 are positioned in a far-field region thereof.

[0136] Another known problem hindering ubiquitous integration of WPT for electric and hybrid vehicle charging, is related to safety requirements. E.g., WPT systems generate strong magnetic fields, which can interfere with other electronic devices, including those in the vehicle and nearby infrastructure. Ensuring EMC compliance is essential to prevent malfunctions. Furthermore, prolonged exposure to strong magnetic fields can pose health risks to humans, particularly for individuals with implanted medical devices like pacemakers. Therefore, regulatory limits on EMF exposure must be adhered to.

[0137] To address this issue, in some embodiments, it is suggested that matching geometric properties of receiving antenna 210 and transmitting antenna 100 may be selected so as to cause, at the desired frequency of the power source, a mismatch of an impedance of transmitting antenna 100 to the impedance of free space. Thereby, transmitting antenna 100 will not be able to propagate radiation in the far-field region efficiently, reducing risk of interference with unintended objects. Despite this, system 200 will still be able to provide strong coupling when antennas 100 and 210 are positioned within the near-field region.

[0138] In some further embodiments, it is suggested that matching geometric properties of receiving antenna 210 and transmitting antenna 100 may be selected so as to cause, at the desired frequency of the power source, a mismatch of an impedance of receiving antenna 210 to the impedance of free space.

[0139] As a result of the suggested configuration, and according to some embodiments of the present invention, a high coupling and highly efficient power transfer occurs between the transmitting antenna 100 and receiving antenna 210, along and across direction P within the charging volume of WPT system 200.

[0140] In one embodiment of this invention, near-filed region represents a reactive near- field region and is defined by the frequency of the power source (also referred herein as ‘first’ frequency) and said matching geometric properties of transmitting antenna 100 and receiving antenna 210.

[0141] It shall be understood that, according to some embodiments, transmitting antenna 100 and receiving antenna 210 are configured to be positioned opposite each other, in substantially parallel planes, within said near-field region (e.g., reactive near-field region). E.g., in relation to electric vehicle charging, transmitting antenna 100 may be attached to the floor surface of the parking lot and receiving antenna 210 may be installed at the bottom of the vehicle and connected to the battery thereof. Thereby, when the vehicle is parked or isdriven above the transmitting antenna, receiving antenna 210 may be positioned within the near-field region (e.g., reactive near-field region) with respect to transmitting antenna 100, enabling strong electromagnetic coupling therebetween.

[0142] Reference is now made to Figs. 8 A and 8B, demonstrating a side view of WPT system 200 and simultaneous coupling and wireless power transfer to multiple receiving antennas 210, 220, 230 and 240 of the same configurations. Fig 8A shows transmitting antenna 100 having lengths LI, enabling simultaneous coupling with 2 receiving antennas 210 and 220. Fig 8B shows transmitting antenna 100 having lengths L2, enabling simultaneous coupling with 4 receiving antennas 210-240.

[0143] According to one embodiment of the present invention, resonance occurs only when at least one of receiving antennas 210-240 is present within the charging volume. As can be seen in Figs. 8A and 8B, WPT system 200 resonates when receiving antennas 210 and 220 are present within the changing volume resulting in a strong simultaneous coupling (2101, 2102, 2103, 2104) and efficient wireless power transfer between transmitting antenna 100 and receiving antennas 210 and 220 along and across direction P within the charging volume.

[0144] According to some embodiments of the present invention, the generation of such simultaneous coupling between transmitting antenna 100 to at least two receiving antennas 210 and 220 makes the transmitting circuit functioning as a wireless power divider, where the power transferred from transmitting antenna 100 is equally divided by at least two receiving antennas (e.g., antennas 210 and 220) positioned within the charging volume. Fig. 8B, in turn, presents the equal wireless power divider of system 200, wherein four receiving antennas (e.g., antennas 210-240) are present within the charging volume, and the power is efficiently wirelessly transferred form transmitting antenna 100 and divided equally between the receiving antennas (e.g., antennas 210-240). It shall be understood that, according to some embodiments, operational frequency (‘first’ frequency) may not differ for the plurality of receiving antennas.

[0145] It should be understood that antennas may be further configured to operate in different harmonics of the power source signal. Therefore, in some embodiments, other harmonics may be used, e.g., to transfer data during power transfer.

[0146] It shall further be understood that disconnection of one of receiving antennas of the plurality may not affect the coupling of the rest of receiving antennas, and the power, in such scenarios, is being split between the rest equally.

[0147] Reference is now made to Figs. 9A-9G illustrate different views of complementary conducting surface 310 of WPT system 200, and parameters thereof, according to some embodiments.

[0148] In some embodiments, WPT system 200 may further include complementary conducting surface 310, adapted to be positioned, in the operational mode, between, and substantially parallel to the conducting surface of transmitting antenna 100 (e.g., signal conductor 101 and ground conductor 102) and the conducting surface of receiving antenna 210 (e.g., signal conductor 211).

[0149] In some further embodiments, the alternating power source may be adapted to generate the alternating electrical signal at a ‘second’ predetermined frequency. It shall be understood that, in the context of the present disclosure, terms ‘first’ frequency and ‘second’ frequency do not relate to any particular order, but rather used to differentiate between the two frequences. In some embodiments, complementary conducting surface 310 may have geometric properties that match those of conducting surfaces of transmitting and receiving antennas 100 and 210 (e.g., conductors 101, 102, 211 and 212, as described above), so as to substantially cancel, in the operational mode, reactance of the WPT system, at the ‘second’ frequency.

[0150] In other words, complementary conducting surface 310 may have such geometric properties that match those of conducting surfaces of transmitting and receiving antennas 100 and 210 (e.g., conductors 101, 102, 211 and 212, as described above), so as to compensate for missing effective electrical length (according to the ‘second’ frequency), thereby allowing resonance condition of WPT system 200 in said ‘second’ frequency.

[0151] The suggested approach may help to solve the problem of using various receiving antennas having different configuration or to use the same receiving antenna with various configurations of transmitting antennas. Complementary conducting surface 310 may help to adjust system 200 to different types of receiving antennas and / or transmitting antennas, increasing flexibility of the system 200 and facilitating its application in different scenarios and use cases, thereby further contributing into the improvement of the relevant technological field.

[0152] Figs. 9A-9B illustrate a bottom and side view of complementary surface 310 respectively, having complementary surface conductor 311 and complementary surface support plate 312. According to some embodiments of the present invention, complementary surface support plate 312 may be made of a dielectric material. Complementary surface support plate 312 may be used to support complementary surface conductor 311 and to provide its desired positioning.

[0153] As can be seen in Fig.9C, the parameters (geometric properties) of complementary surface conductor 311 may include length, width, and thickness of each conductor segment (Lcl - Lcn, Wcl - Wen, Tel - Ten), relative angle (am) and distance (Dcscl - Dcscp) between adjacent conductor segments.

[0154] As can be seen in Figs. 9D-9E, the parameters (geometric properties) of support plate 312 may include length, width and thickness (Ld, Wd, Td) of plate 312. The parameters of relative positioning of complementary surface conductor 311 to support plate 312 may include vertical distance (DcdZl - DcdZk) between them, planar distance between them along their areas (DcdXl - DcdXk and DcdYl - DcdYk) and planar offset (OScdX and OScdY) of plate 312 with respect to conductor 311.

[0155] It shall be understood that, by designing complementary surface 310 with specific values of the abovementioned geometric properties of conductor 311 and plate 312 (shown in Figs. 9A-9E), it may provide for such inductance / capacitance characteristics of transmitting antenna 100 and receiving antenna 210 (and, accordingly, of the entire transmitting circuit and receiving circuit), that when system 200 is in operational mode and complementary surface 310 is positioned between and substantially parallel to antennas 100 and 210, reactance of system 200 may be cancelled, thereby providing for the resonance conditions. In other words, geometric parameters, shown in Figs. 9A-9E, may be selected so as to provide, in the operational mode and when and complementary surface 310 is positioned between and substantially parallel to antennas 100 and 210, a total effective electrical length of WPT system 200 (of the entire circuit thereof), substantially equal to a quarter wavelength of the predefined frequency of the alternating power source (also referred herein as ‘second’ frequency), or an integer product thereof, thereby allowing system 200 to resonate at this frequency.

[0156] Figs. 9F-9G illustrate some alternative embodiments of complementary surface 310. Fig. 9F demonstrates complementary surface 310, which is narrow in X direction andFig 9G demonstrates complementary surface 310 which narrow in Y direction. According to some embodiments of the present invention, complementary surface 310 can significantly vary in geometrical properties, and have different shape, form and dimensions.

[0157] Referring to Fig. 10A, a top view of complementary conducting surface 310 positioned above transmitting antenna 100 is demonstrated, according to some embodiments. Referring to Fig. 10B, a top view of WPT system 200 having complementary conducting surface 310 positioned between transmitting antenna 100 and receiving antenna 210 is demonstrated, according to some embodiments.

[0158] As shown in Figs. 10A-10B, WPT system 200 includes transmitting antenna 100 having length L3, receiving antenna 210 and complementary conducting surface 310. Depending on the specific embodiments of the present invention, complementary surface 310 can be in the same size and dimensions as transmitting antenna 110, larger than the dimensions of transmitting antenna 110, smaller than the dimension of transmitting antenna 110. In yet another embodiment, complementary surface 310 can be placed directly above the transmitting antenna 110 with full alignment, partial alignment (with respect to X axis or Y axis) or complete misalignment (with respect to both X and Y axis). In some other embodiments, complementary surface 310 may be configured to be positioned at certain height (with respect to Z axis) above transmitting antenna 110.

[0159] Complementary conducting surface 310 and conductors 101, 102, 211 and 212 may have such geometric properties that match to provide, in the operational mode with surface 310 positioned between antennas 100 and 210, a total effective electrical length of WPT system 200 substantially equal to a quarter wavelength of the frequency of the power source (the ‘second’ frequency, different from the ‘first’ frequency) or an integer product thereof. Thereby, complementary conducting surface 310, when positioned between transmitting antenna 100 and receiving antenna 210, may be involved in the electromagnetic coupling and may cause electromagnetic coupling to be conducted therethrough, while providing for the desired resonance condition of WPT system 200.

[0160] Reference is now made to Fig. 11 illustrating a side view of WPT system 200, showing coupling and wireless power transfer using complementary conductive surface 310, according to some embodiments.

[0161] As shown, transmitting antenna 100 may have length L3. Complementary surface 310 may be positioned between transmitting antenna 110 and receiving antenna 210 withinthe predefined charging volume or area (in the near-filed region). As a result, and according to some embodiments of the present invention, system 200 including transmitting antenna 100 with length L3, complementary surface 310 and receiving antenna 210, may resonate at predefined frequency of the power source (also referred herein as ‘second’ frequency), thereby enabling strong electromagnetic coupling 2101 and energy transfer from transmitting antenna 100 to receiving antenna 210, that may remain substantially similar within the predefined charging volume or area and along the length L3 of transmitting antenna 100, thus providing for substantially free and unlimited positioning of receiving antenna 210 along the length L3 of the transmitting antenna and along the path P. According to some embodiments of the present invention, receiving antenna 110 can substantially vary in size shape and form, as long as complementary surface 310 of respectively matching geometric properties (as described above) is used, so as to compensate for missing effective electrical length.

[0162] Fig.12 illustrates a side view of WPT system 200, showing simultaneous coupling (2101 and 2102) and wireless power transfer to multiple receiving antennas (receiving antennas 210 and 220), using complementary conductive surface 310, according to some embodiments.

[0163] According to one embodiment of the present invention, resonance occurs only when at least one of receiving antennas 210-220 is present above complementary conducting surface 310, within the charging volume. As can be seen in Fig. 12, WPT system 200 resonates when receiving antennas 210 and 220 are present within the changing volume resulting in a strong simultaneous coupling (2101, 2102) and efficient wireless power transfer between transmitting antenna 100 and receiving antennas 210 and 220 along and across direction P within the charging volume.

[0164] According to some embodiments of the present invention, the generation of such simultaneous coupling between transmitting antenna 100 to at least two receiving antennas 210 and 220, via complementary conducting surface 310, makes the transmitting circuit functioning as a wireless power divider, where the power transferred from transmitting antenna 100 is equally divided by at least two receiving antennas (e.g., antennas 210 and 220) positioned within the charging volume.

[0165] It shall further be understood that, given the same parameters (e.g., geometric properties, frequency of the alternating power source) of the transmitting circuit (includingtransmitting antenna 100) and complementary conducting surface 310, receiving antennas 210 and 220 may, in some embodiments, vary in structure and dimensions. E.g., antenna 210 may have such geometric properties that, in the operational mode and when and complementary surface 310 is positioned between and substantially parallel to antennas 100 and 210, a total effective electrical length of WPT system 200 (of the entire circuit thereof), substantially equal to an integer product n * 2 / 4 of quarter wavelength of the predefined frequency of the alternating power source (also referred herein as ‘second’ frequency); while antenna 220 may have such geometric properties that, in the operational mode and when and complementary surface 310 is positioned between and substantially parallel to antennas 100 and 210, a total effective electrical length of WPT system 200 (of the entire circuit thereof), substantially equal to an integer product m * 2 / 4 of quarter wavelength A of the predefined frequency of the alternating power source (also referred herein as ‘second’ frequency), where n E N; m E N; and m > n, thereby allowing system 200 to resonate at this frequency.

[0166] It shall be understood that the interposition of system 200 elements, as shown in Figs. 10A-10B, 11 and 12, is provided as a non-exclusive example. In other, alternative embodiments, complementary conducting surface 310 may, for example, be positioned below transmitting antenna 100 or aside of transmitting antenna 100 (if antenna 100 is, e.g., oriented vertically), provided that surface 310 is positioned between and substantially parallel to antennas 100 and 210.

[0167] It shall further be understood, that the above-described configuration provides for strong electromagnetic coupling, regardless of whether receiving antennas 210 and 220 are stationary or in motion, or at least one is stationary and another is in motion.

[0168] It shall be understood that, in some embodiments, any of the conducting surfaces applied in system 200 (e.g., conductors 101, 102, 211, 212, 311 and 312) may be characterized by having a round, rectangular, or any other geometrical shape of a crosssection, or combinations thereof.

[0169] It shall further be understood that, in the ‘reverse’ mode, as described above, antenna 100 may function as a power combiner, receiving power from antennas 210 and 220.

[0170] Reference is now made to Figs. 13A and 13B, illustrating a side view of WPT system 200. Fig. 13A demonstrates coupling and wireless power transfer to receivingantennas 220, while having transmitting antenna 100 powered via antenna 210, functioning, in this embodiment, as a feeder antenna. Fig.l3B demonstrates simultaneous coupling (2102, 2103, 2104) and wireless power transfer to multiple receiving antennas 220, 230 and 240, while having transmitting antenna 100 powered via antenna 210, functioning, in this embodiment, as a feeder antenna, via coupling 2101.

[0171] As shown in Figs. 13A-13B, in some embodiments, system 200 may include at least one feeder antenna (in this embodiment, antenna 210 is configured to function as feeder antenna). Feeder antenna (in this embodiment, antenna 210) may include at least one feeding signal conductor (not shown) in a direct or indirect conductive connection with the alternating power source and positioned opposite to conducting surface (conductors 101 and 102) of transmitting antenna 100, within the near-field region thereof. In the embodiments of Figs. 13A and 13B, transmitting antenna may not be conductively connected to the alternating power source, but instead being powered via said at least one feeder antenna (e.g., antenna 210).

[0172] In such embodiments, in order to provide a desired resonance condition, the feeding signal conductor of the feeding antenna (e.g., antenna 210), the conducting surface of transmitting antenna (e.g., conductors 101 and 102), and conducting surface of receiving antenna (e.g., conductors 211 and 212) may have geometric properties matching each other so as to provide, in the operational mode, a total effective electrical length of WPT system 200 substantially equal to a quarter wavelength of the frequency of the power source (also referred herein as ‘first’ frequency) or an integer product thereof.

[0173] According to the embodiment of Figs.l3A and 13B, each of receiving antennas 220-240 may be connected to a respective receiving unit (to a respective plurality of receiving units or to a single one) and transmitting antenna 100 may not be connected to any receiving or transmitting units. Accordingly, antenna 210 is coupled with receiving antenna 220 via transmitting antenna 100, meaning that power is wirelessly transferred from antenna 210 to receiving antenna 220 through transmitting antenna 100. In other words, in such embodiments, transmitting antenna 100 may be used only to create the coupling between antenna 210 and receiving antenna 220, while within the predefined charging volume, which determined by transmitting antenna 100. Accordingly, in such embodiments, system 200 may be configured to resonate in a predefined frequency (also referred herein as ‘first’ frequency) and enables wireless power transfer, in the operational mode, only when ‘feeder’antenna 210, transmitting antenna 100 and at least one of receiving antennas 220-240 are located within the predefined charging volume.

[0174] According to the embodiment shown in Fig. 13B, WPT system 200 can function as wireless power divider, dividing power between antennas 220-240, where antenna 210 functions as input port and antennas 220-240 function as output port. According to some embodiments, WPT system 200 can function as wireless power divider where at least one feeding antenna (e.g., antenna 210) functions as an input port and at least one of receiving antennas 220-240 functions as an output port, where at least one of receiving antennas 220- 240 and feeder antenna 210 may be stationary positioned, in motion or combination of.

[0175] It shall be understood that, depending on embodiments, antenna 210 functioning as a feeder antenna may have same or different geometrical properties (structure, shape, dimensions etc.) than receiving antennas 220-240. Furthermore, receiving antennas 220-240 may also have same or different geometrical properties (structure, shape, dimensions etc.).

[0176] It shall further be understood that, according to some embodiments of the present innovation, WPT system 200 may have more than one feeder antenna. In such embodiments, system 200 may function as a wireless power coupler / combiner, between transmitting units (also referred herein as ‘transmitting circuits’), connected to feeder antennas, and at least one receiving unit (also referred herein as ‘receiving circuit’), connected to at least one other receiving antenna (such as antennas 220-240).

[0177] It should be understood that embodiments shown in Figs. 13A-13B may be applied in practice, e.g., for different bidirectional charging scenarios, like Vehicle-to- Vehicle (V2V), Vehicle-to-Grid (V2G) etc. V2V allows one electric vehicle (EV) to charge another EV. It can be particularly useful in situations where an EV runs out of charge and needs a boost from another vehicle. V2V scenario can be realized, e.g., when antenna 210 is connected to the battery of one ‘source’ vehicle, and antennas 220-240 are connected to batteries of respective ‘charging’ vehicles.

[0178] V2G enables an EV to send electricity back to the power grid. V2G can help balance the grid by providing additional power during peak demand times and storing excess energy during off-peak times. V2G scenario can be realized when antenna 210 is connected to ‘source’ vehicle and the transmitting antenna 100 is connected to means for storing the excess energy.

[0179] Reference is now made to Figs. 14A which illustrates a top view of the WPT system, having a plurality of receiving antennas 210, 220, 230, 240, 250, 260 linearly spaced along the length of transmitting antenna 100, according to some embodiments.

[0180] As shown in Fig. 14A, in some embodiments, receiving antennas 210-260 may be linearly spaced along path P and positioned opposite the conducting surface of transmitting antenna 100 (e.g., opposite conductors 101 and 102) within the near-field region.

[0181] In some embodiments, said receiving antennas 210-260 may include a set of receiving antennas (also referred herein as the ‘first’ set), each placed from a feed point of continuous signal conductor 101 at a distance equal to even integer product of a quarter wavelength of the frequency of the power source (also referred herein as the ‘first’ frequency) and having geometric properties of conducting surface thereof (e.g., conductors 211 and 212) matching said conducting surface of transmitting antenna 100 (e.g., conductors 101 and 102) so as to provide, in the operational mode, an effective electrical length of the segment of WPT system 200 powering the electrical load connected to a respective receiving antenna of the set (the respective antenna 210-260) substantially equal to even integer product of the quarter wavelength of the frequency of the power source.

[0182] It shall be understood that the selection of the location for positioning receiving antennas along the length of transmitting antenna 100, in order to create the desired coupling, depends on the wavelength of the power source signal. As explained above, with different positioning of receiving antenna 210 along the length of transmitting antenna 100, effective electrical length is changed accordingly. Hence, in some embodiments, antennas of the ‘first’ set may have the same configuration which may provide for the substantially equal conditions for electrical coupling, when positioned in the abovementioned distances.

[0183] In some further embodiments, said receiving antennas 210-260 may include a set of receiving antennas (also referred herein as the ‘second’ set), each placed from a feed point of continuous signal conductor 101 at a distance equal to odd integer product of a quarter wavelength of the frequency of the power source (also referred herein as the ‘first’ frequency) and having geometric properties of conducting surface thereof (e.g., conductors 211 and 212) matching said conducting surface of transmitting antenna 100 (e.g., conductors 101 and 102) so as to provide, in the operational mode, an effective electrical length of the segment of WPT system 200 powering the electrical load connected to a respective receivingantenna of the set (the respective antenna 210-260) substantially equal to odd integer product of the quarter wavelength of the frequency of the power source.

[0184] It shall be understood that said grouping of plurality of antennas 210-260 into the abovementioned ‘first’ and ‘second’ sets may depend on wavelength of the signal of the power source at the predefined ‘first’ frequency. E.g., in some embodiments, transmitting antenna 100 may have electrical length shorter than the quarter wavelength of the first frequency of the power source signal. In such configuration, receiving antennas 210-260 may have the same configuration (have same geometric properties) in order to provide for the total effective electrical length of system 200 equal to the integer product of the quarter wavelength. However, in some alternative embodiments, transmitting antenna 100 may have electrical length longer than the quarter wavelength of the first frequency of the power source signal. In such scenarios, the abovementioned grouping of receiving antennas 210-260 into the ‘first’ and the ‘second’ set may be applied, as some of the receiving antennas 210-260 may be positioned along the length of transmitting antenna 100 in regions corresponding to different quarters of the wavelength of the signal passing through the conducting surface of transmitting antenna 100. Accordingly, in order to provide for the desired resonance condition for each receiving antenna 210-260, regardless of their positioning with respect to the quarter wavelength of the signal passing through the conducting surface of transmitting antenna 100, antennas 210-260 may be grouped into the abovementioned ‘first’ and ‘second’ sets, while the configuration of antennas 210-260 may be different depending on the set they pertain to, in order to provide for the desired total effective electrical length. As a result, for the antennas of the ‘first’ set, obtained total effective electrical length of system 200 will be equal to odd integer products of the quarter wavelength, and, for the antennas of the ‘ second’ set, obtained total effective electrical length of system 200 will be equal to even integer products of the quarter wavelength.

[0185] It shall be understood that, depending on the specific selected wavelength of the signal of the power source, antennas 210-260 may be grouped into the ‘first’ and ‘second’ sets differently. E.g., in some embodiments, for relatively long wavelengths, all antennas 210-260 may be in the single set (the ‘first’ or the ‘second’ respectively); in some alternative embodiments, for relatively shorter wavelengths, antennas 210-230 may be in the ‘first’ set and antennas 240-260 may be in the ‘second’ set; in yet another alternative embodiment, foreven shorter wavelengths, antennas 210, 230, 250 may be in the ‘first’ set and antennas 220, 240, 260 may be in the ‘second’ set.

[0186] It shall be appreciated that system 200, as shown in Fig. 14A, may function as a power divider or power combiner, depending on the embodiments, as explained above.

[0187] According to some embodiments, antennas 210-260 may be stationary or movable.

[0188] According to some embodiments, WPT system 200 may have receiving antennas 210, 230 and 250 placed over transmitting antenna 100 where the distance from the beginning of the transmitting antenna 100 (from the feeding point) is n * A / 4, where n = 1,3,5. . and receiving antennas 220, 240, and 260 are placed over transmitting antenna 100 where the distance from the beginning of the transmitting antenna 100 is m * A / 4, where m=2,4,6.... According to some embodiments, receiving antenna 210, 230 and 250 dimensions, structure and form differ from receiving antennas 220, 240 and 260 dimensions, structure and form. According to some embodiments, all receiving antenna of system 300 can be differ from each other, similar to each other or divided into groups by similarity.

[0189] According to some embodiments, at least one receiving antenna of antennas 210- 260 may differ from the others due to different environmental influences. According to some embodiments, at least one receiving antenna of antennas 210-260 may differ from the others due to the antenna connection to different devices or load than the others. According to some embodiments, at least one receiving antenna of antennas 210-260 may differ from the others due to the antenna phase (e.g., transmitting antenna 100 phase). According to some embodiments, at least one receiving antenna of antennas 210-260 may be connected to at least one device circuit or any type of load. According to some embodiments, at least one receiving antenna of antennas 210-260 may by connected to at least one solar panel and function as a power converter to feed transmitting antenna 100 in the abovementioned ‘reverse’ mode.

[0190] Fig. 14B illustrates a top view of WPT system 200, having a plurality of receiving antennas 210-260 linearly spaced along the length of transmitting antenna 100, and coupled with respective transmitting antennas 100A, 100B, 100C, 100D, 100E, 100F and receiving antennas 270, 280, 290, according to some embodiments.

[0191] For the matter of clarity, in the present disclosure, transmitting antenna 100 is referred to as ‘primary’ transmitting antenna, receiving antennas 210-260 are referred to as‘primary’ receiving antennas, transmitting antennas 100A-100F are referred to as ‘secondary’ transmitting antennas and receiving antennas 270, 280, 290 are referred to as ‘secondary’ receiving antennas.

[0192] As can be seen in Fig. 14B, each of said plurality of primary receiving antennas 210-260 (the configuration of transmitting antenna 100 and receiving antennas 210-260 may be same as discussed with reference to Fig. 14A above) may be further configured to power a electrical loads via: (i) secondary transmitting antennas 100A-100F, respectively, and (ii) secondary receiving antennas 270, 280, 290. Each of transmitting antennas 100A-100F may include at least one first mediatory signal conductor, configured to be stretched along a second path P2 and positioned opposite the at least one second conductive surface (e.g., respective conductors 211 and 212) of a respective primary receiving antenna 210-260 within a near-field region thereof. In some embodiments, each of the transmitting antennas 100A-100F may further include at least one mediatory ground conductor.

[0193] Each of secondary receiving antennas 270, 280, 290 may include at least one second mediatory signal conductor (not shown) in operative connection with the respective electrical load (not shown) and positioned opposite to the at least one first mediatory signal conductor (of respective transmitting antenna 100A-100F) within a near-field region thereof.

[0194] In some embodiments, in order to obtain the desired resonance condition providing for efficient power transfer through all the obtained paths (e.g., the power source - transmitting antenna 100 - receiving antenna 250 - transmitting antenna 100E - receiving antenna 290 - the electrical load; and similar) having conductively connected elements and electromagnetically coupled elements, the following is suggested. The second conductive surface (e.g., conductors 211, 212) of the respective primary receiving antenna of antennas 210-260, the respective first mediatory signal conductor (of the respective transmitting antenna 100A-100F), and the at least one second mediatory signal conductor (of the respective receiving antenna 270, 280 and 290) may have geometric properties matching each other so as to provide, in the operational mode, an effective electrical length of the segment of WPT system 200 powering the respective electrical load (such segment as according to the path for powering the electrical load connected to receiving antenna 290, as provided in example above) substantially equal to integer product of the quarter wavelength of the first frequency.

[0195] As shown, and according to some embodiments of the present invention, transmitting antenna 100 transfer wireless EM power to receiving antenna 210 - 260, then the received EM power may be transferred to transmitting antennas 100A-100F. The EM power in transmitting antenna 100A-100F is wirelessly transferred to receiving antennas 270-290 which are attached to mobile device (not shown, e.g., vehicle) that is located within the antenna matrix 1000, meaning that receiving antennas 270 - 290 may receive the wireless power transferred form transmitting antenna 100 in any location within antenna matrix 1000 charging volume. As presented, and according to some embodiments, the output power from transmitting unit (the power source, not shown) may be delivered to transmitting antenna 100, transmitting antenna 100 may wirelessly transfer the power to receiving antennas 210-260. Receiving antennas 210-260 may deliver the received power (without any conversion) to transmitting antenna 100A-100F. The power received by transmitting antennas 100A- 100F may be wirelessly transferred to receiving antenna 270-290. The power received by receiving antennas 270-290 may be delivered to the receiving unit (not shown) for rectification and then for charging the battery (the electrical load) or powering the mobile device (not shown). According to some embodiments, the power may be transfer only in antenna route that directly involved with receiving antennas 270-290. For example, and according to some embodiments, transmitting antenna 100 may wirelessly transfer power to receiving antennas 210, 230 and 250, then the received power may be delivered to transmitting antennas 100A, 100C and 100E which wirelessly transfer the power to receiving antennas 270, 280 and 290. According to some embodiments, power can wirelessly flow in an antenna route that resonates, meaning that the end of the route has at least one receiving antenna connected to the electrical load.

[0196] According to some embodiments of the present invention, receiving antenna 270 may resonate with transmitting antenna 100A at a predefined frequency, reflected a high coupling coefficient and efficient wireless power transfer between transmitting antenna 100A and receiving antenna 270. The resonance condition between said antennas may then be reflected to receiving antenna 210 which set the condition for resonance (at the same frequency, said ‘first’ frequency) with transmitting antenna 100, meaning a high coupling coefficient and efficient wireless power transfer between transmitting antenna 100 and receiving antenna 210. In other words, and according to some embodiments, transmitting antenna 100 may resonate with receiving antenna 270, through the entire resonate route,meaning a high coupling coefficient and efficient wireless power transfer between transmitting antenna 100 and receiving antenna 270 may occurs. According to some embodiments, antenna 100 may resonate at the same frequency with receiving antenna 270, 280 and 290 where a high coupling coefficient and efficient wireless power transfer between transmitting antenna 100 and receiving antennas 270, 280 and 290 may occur simultaneously.

[0197] According to some embodiments, antenna matrix 1000 charging volume may be equal to the summation of all charging volume created by each antenna in the matrix. According to some embodiments, receiving antenna 210-260 may be similar to each other. According to some embodiments, receiving antenna 210-260 may differ from each other. According to some embodiments, transmitting antenna 100A-100F may be similar to each other. According to some embodiments, transmitting antenna 100A-100F may differ from each other.

[0198] It shall be understood that the embodiment shown in Fig. 14B shall not be considered limiting with respect to the sequential connection of transmitting and receiving antennas. That is, in some embodiments, receiving antennas 270, 280 and 290 may be further configured to transfer power via EM coupling with other, third-level transmitting antennas, which may further be coupled with respective, third-level receiving antennas, and so on. Accordingly, in some embodiments, system 200 may represent a multi-layer matrix structure, formed by EM coupling of respective transmitting and receiving antennas, provided that the desired resonance condition is maintained (the desired total effective electrical length is achieved by the matching geometric properties of antennas at all layers).

[0199] Reference is now made to Figs. 15A-15D, showing isometric views of various configurations of receiving antenna 210, according to some alternative embodiments.

[0200] As shown in Fig. 15A, in some embodiments, receiving antenna 210 may include ground conductor 212 functioning as a shield, to inhibit undesirable interference and distribution of EM field. Signal conductor 211 may be connected to coax cable 105 for transferring the received power to the electrical load.

[0201] As shown in Fig. 15B, in some alternative embodiments, receiving antenna 210 may function as a ‘feeder’ antenna, as discussed in other embodiments above, and may be further configured to transfer, from signal conductor 211, via EM coupling, power to secondary signal conductors 221, 231, 241, 251, each having smaller dimensions than signalconductor 211 and being positioned in the near-field region to signal conductor 211, substantially parallel thereto. In some embodiments, wireless power connector 210 may include joint ground conductor 212 functioning as a shield, to inhibit undesirable interference and distribution of EM field. Signal conductors 221-251 may be connected to coax cables 105B, 105C, 105D, 105E, respectively, and being configured to transfer power to the electrical load therethrough. In some alternative embodiments, signal conductor 211 may function as a feeder antenna and may be configured to receive electrical signal via coax cable 105A, instead or in combination with EM coupling with transmitting antenna 100.

[0202] As shown in Fig. 15C, in some alternative embodiments, receiving antenna 210 may have two signal conductors 211 and 231, both spiral-shaped and positioned substantially parallel to each other in the near-field region. Conductor 211 may be powered via two coax cables 105A and 105C, transferring signal from the alternating power source. Conductor 231 (in some respects, may represent ‘secondary’ receiving antenna), may be electromagnetically coupled to conductor 211. Conductor 231 may be connected to coax cable 105B and configured to transfer the received power to the electrical load. Both conductors 211 and 231 may be shielded using ground conductor 212. In other words, coax cables 105A and 105C can be described as main power line, connected to antenna 210 to wirelessly transfer power to or from coax cable 105B (depending on the feeder mode or ‘reverse’ mode, as explained above). In such case, when coax cable 105B is loaded, power received from coax cable 150A is equally divided between coax cable 105B and 105C.

[0203] As shown in Fig. 15D, in some alternative embodiments, antenna 210 may have three signal conductors 211, 221 and 231, all spiral-shaped and positioned substantially parallel to each other in the near-field region. Conductor 211 may be powered via coax cable 105 A, transferring signal from the alternating power source. Conductors 221 and 231 (in some respects, may represent ‘secondary’ receiving antenna), may be electromagnetically coupled to conductor 211. Conductors 221 and 231 may be connected to coax cable 105B and 150C respectively and configured to transfer the received power to the electrical load. Conductors 211, 221 and 231 may be shielded using ground conductor 212. In other words, coax cable 105A can be described as main power line, connected to antenna 210 to wirelessly transfer power to or from coax cables 105B and 105C. In such case, when coax cable 105B and 105C are loaded, power received from coax cable 150A is equally divided between coax cable 105B and 105C.

[0204] It shall be appreciated that, same as in previously described embodiments, conductors 211 and 231, conductors 211, 221 and 231 and conductors 211, 221, 231, 241 and 251 may have matching geometric properties providing for the required total effective electrical length of WPT system 200, and thus enabling the desired resonance condition for system 200 in the operational mode thereof.

[0205] It shall further be understood that, in embodiments shown in Figs. 15A-15C, system 200 may likewise operate as power divider / splitter / combiner, as explained above, wherein power may be divided equally between the receiving ports (receiving antennas or conductors) when loaded. In case one or more ports have high impedance (when unloaded) the system 200 performance may not change, and all the power may simple be divided equally between the rest of loaded ports.

[0206] Referring now to Fig. 16, a side view of secondary transmitting antenna and secondary receiving antenna (such as antenna 270 of Fig. 14B) is demonstrated, showing EM coupling therebetween.

[0207] As shown, in some embodiments, transmitting antenna 220 (may have configuration as receiving antenna 210, described above) may transfer wireless power 2101 to secondary receiving antenna 230. According to some embodiments, antenna 220 and antenna 230 have the same structure dimensions and form. According to some alternative embodiments, antenna 220 and antenna 230 may differ from each other in structure, dimension and form. According to some embodiments, each structure, dimensions and form (in other words, geometric properties) of antennas 220 and 230 may affect, or impose conditions on the distance therebetween (z axis) and the alignment or misalignment over X and Y axis (in order to obtain the desired charging volume and to provide required resonance conditions, i.e., the desired total effective electrical length). Furthermore, in some embodiments, the dimensions, structure and form of antennas 220 and 230 may determine the resonance frequency and the charging volume of novel WPT system 200, and vice versa.

[0208] Reference is now made to Figs. 17A and 17B, showing secondary transmitting antenna 220 and secondary receiving antenna 230 separated by separating surface 130, according to some embodiments.

[0209] Fig. 17B illustrates a schematic view of the receiving circuit having primary receiving antenna 210, secondary transmitting antenna 220 and secondary receiving antenna 230 separated by the separating surface 130, according to some embodiments. Primaryreceiving antenna 210 may be configured to receive power, via EM coupling, from transmitting antenna 100, same as discussed in the embodiments above.

[0210] Secondary transmitting antenna 220 may be conductively connected to primary receiving antenna 210. E.g., secondary transmitting antenna 220 may include at least one first mediatory signal conductor in a direct or indirect conductive connection with primary receiving antenna 210. Secondary receiving antenna 230 may include at least one second mediatory signal conductor in a direct or indirect conductive connection with the electrical load (e.g., connected via receiver 231 to battery 232) and positioned opposite to the at least one first mediatory signal conductor (signal conductor of antenna 220) within a near-field region thereof. Secondary transmitting antenna 220 and secondary receiving antenna 230 may be separated by separating surface 130.

[0211] In some embodiments, separating surface 130 may be made of material having dielectric properties or, alternatively, of a conductive material. It shall be understood that, separating surface 130 is not applied herein in order to provide any intended effect on the EM coupling. In practice, surface 130 may represent, e.g., an electric vehicle body, frame, support or other structural elements, that does not allow direct wired connection from receiving antenna 210 to the electrical load.

[0212] In some further embodiments, in order to provide the desired resonance condition, second conductive surface 211 (of antenna 210), the at least one first mediatory signal conductor (of antenna 220), and the at least one second mediatory signal conductor (of antenna 230) may have geometric properties matching each other so as to provide, in the operational mode, a total effective electrical length of WPT system 200 substantially equal to a quarter wavelength of the frequency of the power source signal (also referred herein as ‘first’ frequency) or an integer product thereof.

[0213] Accordingly, in some embodiments, antenna 220 may be attached to one side of surface 130 and transfer wireless power to antenna 230 which attached to the other side of surface 130. According to some embodiments, antenna 220 transfer wireless power to 230 through surface 130. According to some embodiments, the structure, dimension and form of each antenna 220 and 230, designed under the consideration of surface 130 characteristics (e.g., dielectric characteristics), will determine the resonance frequency and the charging volume of novel WPT system 200.

[0214] It shall be understood that receiving antenna 210 may be configured to receive wireless power transfer from any type of transmitting antenna (not shown), the receiving electric signal may be conductively (e.g., via wires) transferred to antenna 220. Antenna 220 may transfer power wirelessly to antenna 230, through surface 130. The received power from antenna 230 may be conductively transferred to receiver 231, where the electric signal is being rectified and supplied to charge battery unit 232. According to some embodiments of the present invention, the resonance frequency between antenna 220 and 230 may be the same frequency of the signal received from antenna 210.

[0215] Reference is now made to Figs. 18A and 18B, showing schematic isometric views of WPT system 200, wherein transmitting antenna 300 includes two conducting plates 301 and 302 (also referred herein as ‘plate-like signal conductors’) and a plurality of receiving antennas 210A, 210B . . . 210XX is positioned therebetween.

[0216] As shown, transmitting antenna 300 may include plate-like signal conductor 301 (also referred herein as a ‘signal plate’), configured to receive the electrical signal from said alternating power source; and plate-like ground conductor 302 (also referred herein as a ‘ground plate’), substantially parallel to plate-like signal conductor 301 and being in operative communication with a ground of said alternating power source. In such configuration, the conductors 301, 302 of transmitting antenna 300 may have geometric properties matching those of respective conductors of each receiving antenna 210A-210XX (such as conductors 211 and 212, discussed above) so as to substantially cancel, in the operational mode, reactance of WPT system 200, at the frequency of the power source (also referred herein as ‘first’ frequency), when the conducting surface (e.g., surface 211, 212) of the respective receiving antenna 210A-210XX is positioned between conductors 301-302 within a near-field region thereto.

[0217] The two plates (conductors 301 and 302) may be connected to transmitting unit (not shown) and create a capacitor-like structure. According to some embodiments, the two plates may have similar dimensions, form and structure (i.e., geometric properties). According to some embodiments, the two plates may be aligned to each other. According to some embodiments, the two plates differ in shape, dimensions and structure (i.e., geometric properties). According to some embodiments, the two plates may not be aligned to each other. According to some embodiments, the two plates may define the charging volume, wherein EM coupling and power transfer applicable. As shown, and according to someembodiments, antenna 300 may be configured not to resonate when at least one of receiving antennas 210A-210XX is not presented within the charging volume. According to some embodiments, the conductors 301 and 302 may significantly vary in structure, shape and form (i.e., in geometric properties).

[0218] According to some embodiments, system 200 may resonate once at least one receiving antenna 210 is presented within the charging volume resulting in high coupling coefficient and efficient simultaneous wireless power transfer between transmitting antenna 300 and receiving antennas 210A-210XX, regardless (or without having significant limits) to the position, orientation, rotation, alignment etc. of the at least one receiving antenna within the predefined charging volume.

[0219] According to some embodiments, in the configuration shown in Figs. 18A-18B, system 200 may likewise function as wireless power divider or combiner, where at least two of receiving antennas 210A-210XX and transmitting antenna 300 may function as wireless power divider or combiner ports, respectively.

[0220] Reference is now made to Figs. 19A-19B, showing aspects of EM field distribution in the operational mode of WPT system 200, according to some embodiments, and also to Figs. 20A-20C showing an improved configuration of WPT system 200 having shielding conductor 301A for mitigation of the undesired EM field distribution, according to some embodiments.

[0221] As shown, in some embodiments, the EM field distribution around receiving antenna 210 presented in Fig. 19A may be measured, as demonstrated in Fig. 19B (showing cross-section A, as indicated in Fig. 19A). As can be seen in Fig. 19B the highest power density 2101 may be measured in the vicinity of receiving antenna 210. As additionally shown, DI indicates the distance where the power density and field strength level 2101 are meeting the safety limit level acceptable, for side EM field distribution by receiving antenna 210.

[0222] Referring to Fig. 20A, as solution for mitigating undesired EM field distribution is demonstrated. In particular, system 200 may include transmitting antenna 300. Antenna 300 may further include at least one active shielding conductor 301 A at least partially surrounding continuous signal conductor 30 IB (such as conductor 101, discussed above) along the length thereof in a frame-like manner and being configured to receive the electrical signal from the alternating power source (e.g., being conductively connected thereto).Antenna 300 may further include ground conductor 302 (such as conductor 202, discussed above).

[0223] In some embodiments, continuous signal conductor 301B and active shielding conductor 301A may have geometric properties matching so that the active shielding conductor 301A and the continuous signal conductor 301B are configured to generate electromagnetic fields with a predetermined phase differences so as to create, in the operational mode, a constructive interference in the direction towards receiving antenna 210 and a destructive interference in the direction perpendicular thereto (direction of side EM field distribution). Thereby, the problem of undesired EM field distribution may be effectively addressed, further contributing to the improvement of the relevant technological field.

[0224] According to some embodiments, conductors 301A and 301B may be fed from the same transmitting unit (not shown) with the same power transmitting profile (frequency, phase, power etc.). According to some embodiments, signal conductors 301A and 301B may be connected to the different transmitting unit (not shown) where each transmit signal is differ in at least one of the power transmitting profile characteristics (frequency, phase, power etc.). According to some embodiments, the number of signal conductors is not limited and can be in even of odd order. According to some embodiments, the transmitting from at least two signal conductors (e.g., conductors 301A and 301B) may affect the EM field distribution. According to some embodiments, the at least two conductors 301A and 301B may be centered according to at least one axis (X, Y, Z). According to some embodiments, the EM field and power distribution can be changed (defined) by changing the at least one power transmitting profile characteristics (power, phase, frequency etc.) of at least one of these conductors, relative to another of these conductors. According to some embodiments, the at least two conductors can be fed by at least one transmitting unit, where each signal received by each signal conductor may be similar or may differ in at least one of the power transmitting signal characteristics (power, phase, frequency etc.).

[0225] Fig. 20A further demonstrates the dimensions (geometric properties) and relative positioning parameters of conductors 301A, 301B and 302 of antenna 300. As shown, in some embodiments, the dimensions and relative positioning of the conductors of transmitting antenna 300 may set the desired charging volume. According to some embodiments, the dimensions and relative positioning of the conductors of transmittingantenna 300 may affect the creation and EM field distribution. According to some embodiments, the dimensions and relative positioning of the conductors of transmitting antenna 300 may affect the creation and EM field distribution in addition to the power transmitting profile characteristics of each signal conductor. According to some embodiments, the conductors 301A and 301B of antenna 300 may be referenced to a single common ground (conductor 302) or a few separated ground levels.

[0226] Referring to Figs. 20B-20C, a configuration of WPT system 200 having shielding conductor of antenna 300 for mitigation of the undesired EM field distribution is demonstrated, according to some embodiments.

[0227] As shown, in some embodiments, the field distribution around receiving antenna 210 may be measured, as shown in Fig. 20B and presented in FIG 12B (which is a crosssection A of system 200). As shown, transmitting antenna 300 may include two conductors 301A and 301B (where 301A is an active shielding conductor and 301B is a signal conductor), each conductor being connected to transmitting unit (not shown). As can be seen in Fig. 20C, and according to some embodiments, by changing at least one power transmitting profile parameter, such as power, phase, frequency etc., of one of the conductors 301A and 301B, in relation to the at least one power transmitting profile parameters of another of conductors 301A and 301B, the field distribution, power density and field strength level 2101 can be adjusted.

[0228] According to some embodiments, the power density and field strength level 2101 adjustment does not affect the coupling condition between transmitting antenna 300 and receiving antenna 210 within the charging volume, meaning that the high wireless power transfer efficiency condition maintained, regardless of, or without imposing substantial limitations to the position, orientation, location and rotation of receiving antenna 210 in relation to transmitting antenna 300 while within the charging volume. As can be seen in Fig. 20C, and according to some embodiments, the highest power density 2101 is measured in the vicinity of receiving antenna 210.

[0229] As additionally shown, D2 represents the distance where the power density and field strength level 2101 are meeting the safety limit level acceptable from the side EM field distribution of the receiving antenna 210. As can be seen D2 is substantially lower than DI, shown in Fig. 19B.

[0230] According to some embodiments, WPT 200 may contain various types of receiving antenna, having various kinds of structure, shape, dimension and form, as long as the required resonance condition is met, and the desired total effective electrical length is achieved. According to some embodiments, WPT system 200 of Figs. 20B-20C may transfer power to at least two receiving antennas simultaneously, same as discussed in relation to other embodiments above.

[0231] Reference is now made to Figs. 21A-21D, illustrating aspects of an equivalent electrical circuit of WPT system 200, according to some embodiments of the present invention.

[0232] As schematically shown in Fig. 21 A, the transmitting circuit, including transmitting antenna 100 and the alternating power source, as described above, may be represented by equivalent circuit 1000 characterized by impedance Ztx (element 1001).

[0233] As schematically shown in Fig. 21B, the receiving circuit, including receiving antenna 210 and the electrical load, as described above, may be represented by equivalent circuit 2100 characterized by impedance Zrx (element 2101).

[0234] Figs. 21A and 21B represent the transmitting circuit and the receiving circuit when antennas 100 and 210 are not placed opposite each other (that is, system 200 is not in the operational mode). In other words, antenna 210 is not present in the charging volume and, therefore, no mutual EM influence occurs between circuits. Furthermore, the impedances of both transmitting and receiving circuits, in some embodiments, may be selected such that they do not match the impedance of the free space, thereby causing reflections and mitigating propagation of the radiation into the free space.

[0235] Each of the circuits is characterized by certain impedance value (Ztx and Zrx) at this, non-operational state. The impedance of each circuit may be determined by the physical structure of its conductors (or geometric properties, as discussed above) and the relation between them with respect to the free-space condition.

[0236] Figs. 21C and 21D, in turn, demonstrate system 200 in the operational mode. As can be seen in Fig. 21C, receiving antenna 210 is positioned above and in the charging volume of transmitting antenna 100, and being electromagnetically coupled therewith.

[0237] In result of such coupling, and in view of the matching geometric properties, as discussed above, mutual influence occurs between the receiving and transmitting circuits, leading to creation of new impedance component Zminf (element 2002, shown in Fig. 2 ID)and changing the impedances reflected from each antenna to Ztx ’ (element 1002, shown in Fig. 21D) and Zrx ’ (element 2102, shown in Fig. 21D), where mutual reactance is substantially cancelled.

[0238] As described previously and according to some embodiments, WPT system 200 may be configured to resonate and provide for a high coupling and highly efficient power transfer occurring between transmitting antenna 100 and receiving antenna 210, along and across direction P within the charging volume of WPT system 200. According to some embodiments, WPT system 200 antenna characteristic (reactance (capacitance, inductance) etc.) values may cancel each other and enable maximal transfer of power from the source (transmitting unit) to the load (receiving unit), in oppose to known approaches of magnetic induction, capacitive coupling or other techniques where additional (auxiliary) lump components and resonance circuits are required, which results in a band narrowing, increased alignment sensitivity, low system adaptivity, significant weight increase, cost increase and other critical limitations. According to some embodiments, WPT system 200 maintain substantially the same antenna characteristics in any location, position, rotation and orientation of receiving antenna 210 within the designated charging volume and along and across P direction where transmitting antenna 100 and receiving antenna 210 antenna characteristic (impedance characteristic) values may cancel each other and enable maximal power transfer from the source (transmitting unit) to the load (receiving unit). According to some embodiments, and as explained above, the changes in WPT system 200 antennas characteristics (reactance (capacitance, inductance) etc.) values may be affected relative to the total effective electrical length and / or wavelength according to the location, position, rotation, and orientation of the receiving antenna within the charging volume along and across P direction. According to some embodiments, the described physical phenomena of WPT system 200 is provided by an electrostatic spatial resonator configuration based on non-capacitor structure.

[0239] According to some embodiments, the equivalent circuit of WPT system 200 may be represented as Pi network. As shown, and according to some embodiments, the equivalent circuit of WPT system 200 may be represented as L network. According to some embodiments, the equivalent circuit of WPT system 200 may be represented as Pi, L, any other structure, or combination of networks.

[0240] Figs. 21E and 21F further demonstrate non-limiting possible configurations for equivalent circuit of system 200 for various types of antennas. Any changes in the physical structure (e.g., geometric properties) of any antenna element may respectively change the antenna impedance, where this change will cause changes in the mutual influence impedance and the other antenna impedance. Accordingly, as explained above, the desired resonance condition may be achieved wherein the reactance of the entire circuit of WPT system 200 is substantially cancelled, thereby providing for strong EM coupling.

[0241] As can be seen by the provided description, the present invention provides a WPT system configured to cover relatively large area and volume while maintaining continuance, constant, high coupling and efficient energy transfer between the transmitter and the receiver of an in-motion wireless powering and charging system.

[0242] In contrast to the solution known in the art, having both the transmitting and the receiving antennas or coils designed to have self-resonance in the same frequency, with or without the presence of another antenna or coil within the charging volume, in order to achieve high energy transfer efficiency, the disclosed spatial WPT system for wireless power transfer predefine resonance frequency is designable, determined and occurring by both transmitting antenna and receiving antenna.

[0243] Accordingly, as can be seen in the provided description, the suggested WPT system provides an improvement of the technological field of electrical power supply by reducing the alignment accuracy required for efficient electromagnetic coupling and power transfer. This enhancement, in turn, may significantly facilitate the use of WPT for mobile applications, such as electric vehicle charging.

Claims

CLAIMS1. A Wireless Power Transfer (WPT) system comprising: at least one primary transmitting antenna, comprising at least one first conducting surface connectable to an alternating power source and being adapted to receive an alternating electrical signal, at a first frequency, therefrom; and at least one primary receiving antenna, comprising at least one second conducting surface connectable to an electrical load, wherein the at least one first conducting surface, and at least one second conducting surface have matching geometric properties, defined so as to substantially cancel, in an operational mode, reactance of the WPT system at the first frequency.

2. The WPT system of claim 1, wherein the operational mode is determined by a set of conditions comprising:(i) said at least one first conducting surface being in operative connection with the alternating power source and receiving the alternating electrical signal at the first frequency;(ii) said at least one second conducting surface being in operative connection with the electrical load; and(iii) said at least one primary transmitting antenna and at least one primary receiving antenna being positioned opposite each other within a near-field region thereof.

3. The WPT system of claim 1, wherein the first frequency is not substantially equal to a natural resonance frequency of a transmitting electrical circuit, comprising said at least one primary transmitting antenna, when said at least one primary transmitting antenna and said at least one primary receiving antenna are positioned in a far-field region thereof.

4. The WPT system of claim 1, wherein the first frequency is not substantially equal to a natural resonance frequency of a receiving electrical circuit, comprising said at least one primary receiving antenna, when said at least one primary transmitting antenna and said at least one primary receiving antenna are positioned in a far-field region thereof.

5. The WPT system of claim 1, wherein said matching geometric properties are further defined so as to substantially avoid self-resonance of said at least one primary transmittingantenna and said at least one primary receiving antenna at the first frequency, when said at least one primary transmitting antenna and said at least one primary receiving antenna are positioned in a far-field region thereof.

6. The WPT system of claim 1, wherein said matching geometric properties are further defined so as to cause, at the first frequency, a mismatch of an impedance of said at least one primary transmitting antenna to the impedance of free space.

7. The WPT system of claim 1, wherein said matching geometric properties are further defined so as to cause, at the first frequency, a mismatch of an impedance of said at least one primary receiving antenna to the impedance of free space.

8. The WPT system of claim 1, wherein the near-filed region represents a reactive nearfield region and is defined by the first frequency and said matching geometric properties.

9. The WPT system of claim 8, wherein the at least one primary transmitting antenna and the at least one primary receiving antenna are configured to be positioned opposite each other, in substantially parallel planes, within said near-field region.

10. The WPT system of claim 1, wherein said matching geometric properties are further defined so as to provide, in the operational mode, a total effective electrical length of the WPT system, substantially equal to a quarter wavelength of the first frequency or an integer product thereof.

11. The WPT system of claim 1, wherein the at least one second conducting surface comprises: a continuous planar spiral signal conductor; and a plate-like ground conductor; wherein said continuous planar spiral signal conductor and said plate-like ground conductor are positioned substantially parallel to each other.

12. The WPT system of claim 1, wherein said antennas are devoid of auxiliary capacitive or inductive devices.

13. The WPT system of claim 1, wherein the at least one first conducting surface comprises:a continuous signal conductor, configured to be stretched along a first path, and receive the electrical signal from said alternating power source; and at least one ground conductor, configured to be stretched along said first path, substantially parallel to the signal conductor, and being in operative communication with a ground of said alternating power source.

14. The WPT system of claim 13, wherein said at least one primary receiving antenna comprises a plurality of primary receiving antennas linearly spaced along said first path and positioned opposite the at least one first conducting surface within the near-field region.

15. The WPT system of claim 14, wherein said plurality of primary receiving antennas comprises a first set of primary receiving antennas, each placed from a feed point of the continuous signal conductor at a distance equal to even integer product of a quarter wavelength of the first frequency and having geometric properties of said at least one second conducting surface thereof matching said at least one first conducting surface so as to provide, in the operational mode, an effective electrical length of the segment of the WPT system powering the electrical load connected to a respective primary receiving antenna of the first set substantially equal to even integer product of the quarter wavelength of the first frequency.

16. The WPT system according to any one of claims 14-15, wherein said plurality of primary receiving antennas further comprises a second set of primary receiving antennas, each distanced from the feed point of the continuous signal conductor at a distance equal to odd integer product of a quarter wavelength of the first frequency and having geometric properties of said at least one second conducting surface thereof matching said at least one first conducting surface so as to provide, in the operational mode, an effective electrical length of the segment of the WPT system powering the electrical load connected to a respective primary receiving antenna of the second set substantially equal to odd integer product of the quarter wavelength of the first frequency.

17. The WPT system according to any one of claims 14-16, wherein each of said plurality of primary receiving antennas is further configured to power a respective electrical load via: a secondary transmitting antenna, comprising at least one first mediatory signal conductor, configured to be stretched along a second path and positioned opposite the atleast one second conductive surface of a respective primary receiving antenna within a near-field region thereof; and a secondary receiving antenna, comprising at least one second mediatory signal conductor in operative connection with the respective electrical load and positioned opposite to the at least one first mediatory signal conductor within a near-field region thereof; wherein said second conductive surface of the respective primary receiving antenna, the at least one first mediatory signal conductor, and the at least one second mediatory signal conductor have geometric properties matching each other so as to provide, in the operational mode, an effective electrical length of the segment of the WPT system powering the respective electrical load substantially equal to integer product of the quarter wavelength of the first frequency.

18. The WPT system of claim 13, wherein the at least one first conducting surface further comprises: at least one active shielding conductor at least partially surrounding the continuous signal conductor along the length thereof in a frame-like manner and being configured to receive the electrical signal from the alternating power source; wherein said continuous signal conductor and said at least one active shielding conductor have geometric properties matching so that the at least one active shielding conductor and the continuous signal conductor are configured to generate electromagnetic fields with a predetermined phase differences so as to create, in the operational mode, a constructive interference in the direction towards the at least one primary receiving antenna and a destructive interference in the direction perpendicular thereto.

19. The WPT system of claim 1, further comprising: at least one secondary transmitting antenna, comprising at least one first mediatory signal conductor in a direct or indirect conductive connection with the at least one primary receiving antenna; at least one secondary receiving antenna, comprising at least one second mediatory signal conductor in a direct or indirect conductive connection with the electrical load and positioned opposite to the at least one first mediatory signal conductor within a near-field region thereof;wherein said secondary transmitting antenna and said secondary receiving antenna are separated by a separating surface; and wherein said second conductive surface, the at least one first mediatory signal conductor, and the at least one second mediatory signal conductor have geometric properties matching each other so as to provide, in the operational mode, a total effective electrical length of the WPT system substantially equal to a quarter wavelength of the first frequency or an integer product thereof.

20. The WPT system of claim 1, wherein the at least one first conducting surface comprises: a plate-like signal conductor, configured to receive the electrical signal from said alternating power source; and a plate-like ground conductor, substantially parallel to the plate-like signal conductor and being in operative communication with a ground of said alternating power source; wherein said matching geometric properties are defined so as to substantially cancel, in the operational mode, reactance of the WPT system, at the first frequency, when the at least one second conducting surface is positioned between the plate-like signal conductor and the plate-like ground conductor within a near- field region thereto.

21. The WPT system of claim 1, wherein the at least one first conducting surface and the at least one second conducting surface are further configured to form, in the operational mode, an electrostatic special resonator.

22. The WPT system of claim 1, further comprising at least one feeder antenna, comprising at least one feeding signal conductor in a direct or indirect conductive connection with the alternating power source and positioned opposite to the at least one first conducting surface within a near-field region thereof; wherein said at least one primary transmitting antenna is being powered via said at least one feeder antenna; and wherein said at least one feeding signal conductor, the at least one first conducting surface, and at least one second conducting surface have geometric properties matching each other so as to provide, in the operational mode, a total effective electrical length ofthe WPT system substantially equal to a quarter wavelength of the first frequency or an integer product thereof.

23. The WPT system of claim 1, wherein the WPT system further comprises a complementary conducting surface, adapted to be positioned, in the operational mode, between, and substantially parallel to the at least one first conducting surface and at least one second conducting surface.

24. The WPT system of claim 23, wherein the alternating power source is adapted to generate the alternating electrical signal at a second, predetermined frequency, and wherein the complementary conducting surface has geometric properties that match those of the at least one first conducting surface and at least one second conducting surface, so as to substantially cancel, in the operational mode, reactance of the WPT system, at the second frequency.

25. The WPT system of any one of claims 23-24, wherein said geometric properties of the complementary conductive surface are defined so as to provide, in the operational mode, a total effective electrical length of the WPT system, when the complementary conducting surface is positioned between, and substantially parallel to the at least one first conducting surface and at least one second conducting surface within the near-field region therebetween, substantially equal to a quarter wavelength of the second frequency or an integer product thereof.

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