Power-free Relay Device

Abstract

To provide a passive relay device capable of giving a specific directivity, suppressing unnecessary radiation, reducing size and height, and radiating in two or four directions with a single device.SOLUTION: A passive relay device comprises: a first gate antenna part 2 that has first openings 2a at both ends and has top and ground plate parts and a first wall part 2b; and a second gate antenna part 3 that is installed on the first gate antenna part and has first openings at both ends opening in a direction orthogonal to an opening direction of the first openings in a plan view and has top and ground plate parts and a second wall part 3b. The top plate part of the first gate antenna part and the ground plate part of the second gate antenna part form a rectangular shared plate part 4 where they are integrated with each other. The top plate part of the first gate antenna part and the ground plate part of the second gate antenna part in the shared plate part are formed with a coupling through-hole 5 for electromagnetically coupling the first and second gate antenna parts to each other.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a passive relay device that increases communication capacity and communication distance in communication between a terminal such as a mobile phone and a base station.

Background Art

[0002] Generally, in communication between a terminal such as a mobile phone and a base station, in order to increase communication capacity and communication distance, measures such as increasing the output power of the base station (including an optical fiber network) and dense installation (inside and outside buildings) have been taken. Also, in specific communications, considering installation costs, passive reflectors, large passive relay devices, etc. are installed on mountain slopes, the tops of iron towers, etc. instead of base stations.

[0003] In communication between a terminal and a base station, increasing the output power of the base station or increasing the facilities of the base station itself poses problems such as an increase in the cost required for communication, waste of energy, and unnecessary radiation of electromagnetic waves. Conventionally, passive relay devices using dipole antennas and loop antennas have been proposed.

[0004] For example, Patent Document 1 describes a weak radio wave passive relay device using a half-wavelength dipole antenna or a one-wavelength loop antenna as a feed point short-circuited passive antenna element that resonates effectively at a predetermined frequency. Also, Patent Document 2 describes a large wireless transmission device placed on a transmission tower or the like and using a parabolic antenna or a Yagi antenna.

[0005] Furthermore, Patent Document 3 describes a dual antenna device having a receiving antenna with an aperture area being a plane orthogonal to the incident wave, a transmitting antenna having a reflector and an aperture area being a plane parallel to the reflection direction which is the transmitting direction, and sharing a part of the structure of the transmitting antenna and the receiving antenna and having the transmitting antenna and the receiving antenna provided in the same plane.

Prior Art Documents

Patent Documents

[0006] Patent Document 1 Japanese Patent Laid-Open No. 63-142926 Patent Document 2 Japanese Patent Laid-Open No. 2008-131371 Patent Document 3 Japanese Patent Laid-Open No. 2013-197758 SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, even in the above-mentioned conventional technologies, the following problems remain. That is, in the technology of Patent Document 1, there is a disadvantage that it has a uniform directivity, it is difficult to say that the communication distance is remarkably extended, and unnecessary radiation cannot be suppressed. In particular, a dipole antenna and a loop antenna are almost omnidirectional, and the energy of the incoming wave (electromagnetic wave to be relayed) is dissipated, resulting in weak energy. For this reason, it cannot be installed close to a structure, and it is necessary to install it at a distance from the structure. In addition, in the technology of Patent Document 2, there is a problem that it is difficult to miniaturize and make low-profile to the extent that it can be installed inconspicuously in the usage environments of general wireless LANs and mobile phones. Furthermore, in recent years, due to the increase in free space attenuation and narrow beamforming in 5G millimeter waves, it has been desired to improve the communication quality in blind spots (radio wave dead zones) such as between buildings. Therefore, two-way radiation is required at intersections and T-junctions such as corridors that are likely to be radio wave dead zones indoors. However, in the technology of Patent Document 3, since it can cover only one direction, it is necessary to install two units to cover two directions.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to provide a passive relay device that can obtain a specific directivity, suppress unnecessary radiation, can be miniaturized and made low-profile, and can radiate in two directions and four directions with one unit. MEANS FOR SOLVING THE PROBLEMS

[0009] In order to solve the above problems, the present invention adopts the following configuration. That is, the wireless power relay device according to the first invention has a first gate antenna portion having a rectangular cross section formed of a conductor and having a pair of first openings at both ends, a top plate portion and a bottom plate portion facing each other vertically, and a pair of first wall portions facing each other horizontally, and a second gate antenna portion having a pair of second openings formed of a conductor and having a pair of second openings at both ends opening in a direction orthogonal to the opening direction of the first opening in a plan view, a top plate portion and a bottom plate portion facing each other vertically, and a pair of second wall portions facing each other horizontally. The top plate portion of the first gate antenna portion and the bottom plate portion of the second gate antenna portion are a rectangular shared plate portion integrated with each other, and coupling through holes for electromagnetically coupling the first gate antenna portion and the second gate antenna portion to each other are formed in the top plate portion of the first gate antenna portion and the bottom plate portion of the second gate antenna portion of the shared plate portion.

[0010] In this wireless power relay device, since coupling through holes for electromagnetically coupling the first gate antenna portion and the second gate antenna portion to each other are formed in the top plate portion of the first gate antenna portion and the bottom plate portion of the second gate antenna portion of the shared plate portion, when one of the first gate antenna portion and the second gate antenna portion receives, the other is electromagnetically coupled through the coupling through holes, so that the received electromagnetic wave can be transmitted to the other and transmitted in two directions and four directions. In addition, since the openings of the first gate antenna portion and the second gate antenna portion are arranged to be rotated by 90 degrees in a plan view, the re-radiation operation can be performed in four directions, and unnecessary radiation can also be suppressed. For example, by installing the wireless power relay device of the present invention having directivity in four directions at the center of the ceiling at the intersection inside the structure, it becomes possible to efficiently re-radiate in the four passage directions constituting the intersection. In addition, in the wireless power relay device of the present invention, since it has a two-stage configuration of the first gate antenna portion and the second gate antenna portion having a rectangular cross section, it is possible to reduce the size and height.

[0011] The power - free relay device according to the second invention is characterized in that, in the first invention, the shared plate portion is a single conductive plate in which the top plate portion of the first gate antenna portion and the bottom plate portion of the second gate antenna portion are shared with each other. That is, in this power - free relay device, since the shared plate portion is a single conductive plate in which the top plate portion of the first gate antenna portion and the bottom plate portion of the second gate antenna portion are shared with each other, it is possible to make the device lower - profile and lighter.

[0012] The power - free relay device according to the third invention is characterized in that, in the first invention, the shared plate portion is composed of the top plate portion of the first gate antenna portion, the bottom plate portion of the second gate antenna portion, and an insulating layer formed of a dielectric between the top plate portion of the first gate antenna portion and the bottom plate portion of the second gate antenna portion. That is, in this power - free relay device, since the shared plate portion is composed of the top plate portion of the first gate antenna portion, the bottom plate portion of the second gate antenna portion, and an insulating layer formed of a dielectric between the top plate portion of the first gate antenna portion and the bottom plate portion of the second gate antenna portion, the top plate portion of the first gate antenna portion and the bottom plate portion of the second gate antenna portion, which are in proximity with the dielectric sandwiched therebetween, are electromagnetically coupled by the coupling through - holes for bonding, and characteristics such as the radar cross - section (RCS) can be improved. Also, the shared plate portion can be easily manufactured using a printed circuit board process such as a copper - clad laminate having a three - layer structure of conductor + dielectric + conductor.

[0013] The power - free relay device according to the fourth invention is characterized in that, in any one of the first to third inventions, the coupling through - hole is in a slot shape extending along the diagonal line of the shared plate portion. That is, in this wireless power relay device, since the coupling through-hole is in the shape of a slot extending on the diagonal line of the shared plate portion, it is possible to electromagnetically couple the first gate antenna portion and the second gate antenna portion with high coupling efficiency and transmit a signal. That is, when the coupling through-hole extends in a direction parallel to the pair of first openings or the pair of second openings, the coupling efficiency becomes small, but when it extends in a direction perpendicular thereto, the coupling efficiency becomes large. In particular, the first gate antenna portion and the second gate antenna portion can be electromagnetically coupled with high coupling efficiency by the slot-shaped coupling through-hole extending on the diagonal line in the middle, and a signal can be transmitted.

[0014] The wireless power relay device according to the fifth invention is characterized in that, in the fourth invention, the shared plate portion is square, and the coupling through-hole extends at an angle of 45° with respect to one side of the shared plate portion. That is, in this wireless power relay device, since the coupling through-hole extends at an angle of 45° with respect to one side of the shared plate portion, re-radiation at the same level is possible in the four opening directions of the pair of first openings and the pair of second openings.

[0015] The wireless power relay device according to the sixth invention is characterized in that, in any one of the first to fifth inventions, the first wall portion and the second wall portion are composed of a plurality of wall conductive pins standing side by side along the edge of the shared plate portion. That is, in this wireless power relay device, since the first wall portion and the second wall portion are composed of a plurality of wall conductive pins standing side by side along the edge of the shared plate portion, the wall conductive pins can serve as substitutes for the side plates of the first wall portion and the second wall portion to form the first gate antenna portion and the second gate antenna portion having a rectangular cross-section.

[0016] The wireless power relay device according to the seventh invention is characterized in that, in any one of the first to sixth inventions, a plurality of unit antennas composed of the first gate antenna portion and the second gate antenna portion are installed with the first openings facing the same direction. That is, in this wireless relay device, a plurality of unit antennas each composed of a first gate antenna unit and a second gate antenna unit are installed with their first openings facing the same direction. Therefore, by forming an array of unit antennas, the gain can be improved, and the directivity in the opening directions of the first and second openings can be further amplified to obtain a sharp directivity. Accordingly, the directivity on the assumed installation surface can be made very small, and it becomes possible to install the device close to a structure. Note that the larger the number of arrays (installation number) of unit antennas, the more the gain can be improved.

[0017] The wireless relay device according to the eighth invention is characterized in that, in the seventh invention, a plurality of the unit antennas are respectively installed on a plurality of different planes spaced apart in the vertical direction. That is, in this wireless relay device, a plurality of unit antennas are respectively installed on a plurality of different planes spaced apart in the vertical direction. Therefore, the plurality of unit antennas are arranged in a state where they are stacked in the vertical direction, and the gain can be increased and the space can be saved.

[0018] The wireless relay device according to the ninth invention is characterized in that, in the seventh or eighth invention, the plurality of unit antennas are composed of a first unit antenna and a second unit antenna having different operating frequencies from each other. That is, in this wireless relay device, the plurality of unit antennas are composed of a first unit antenna and a second unit antenna having different operating frequencies from each other. Therefore, relaying can be performed at different operating frequencies.

Effects of the Invention

[0019] According to the present invention, the following effects can be obtained. According to the wireless relay device of the present invention, a coupling through-hole for electromagnetic coupling between the first gate antenna part and the second gate antenna part is formed in the top plate part of the first gate antenna part and the bottom plate part of the second gate antenna part of the shared plate part. Therefore, when one of the first gate antenna part and the second gate antenna part receives a signal, the other is electromagnetically coupled through the coupling through-hole, and the received electromagnetic wave can be transmitted to the other and then transmitted in four directions. In addition, since the openings of the first gate antenna part and the second gate antenna part are arranged in a 90-degree rotation in a plan view, the re-radiation operation can be performed in four directions, unnecessary radiation can be suppressed, and miniaturization and low-profile design are possible. Therefore, the wireless relay device of the present invention is suitable as a relay device for communication such as mobile phones and wireless LANs, and can be miniaturized and made low-profile to the extent that it can be installed inconspicuously inside or near a structure.

Brief Description of the Drawings

[0020]

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Embodiments for Carrying Out the Invention

[0021] Hereinafter, a first embodiment of the wireless power relay device according to the present invention will be described with reference to FIGS. 1 to 3.

[0022] The power - free relay device 1 in this embodiment is a so - called passive repeater. As shown in FIGS. 1 and 2, it has a pair of first openings 2a at both ends, is formed of a conductor such as metal, and has a top plate portion and a bottom plate portion that face each other vertically and a pair of first wall portions 2b that face each other horizontally, forming a first gate antenna portion 2 with a rectangular cross - section. It also includes a second gate antenna portion 3 that is installed on the first gate antenna portion 2, has a pair of second openings 3a at both ends that open in a direction orthogonal to the opening direction of the first openings 2a in a plan view, is formed of a conductor such as metal, and has a top plate portion and a bottom plate portion that face each other vertically and a pair of second wall portions 3b that face each other horizontally, forming a rectangular cross - section.

[0023] The top plate portion of the first gate antenna portion 2 and the bottom plate portion of the second gate antenna portion 3 are a rectangular shared plate portion 4 that is integrated with each other. The shared plate portion 4 of this embodiment is a single conductor plate in which the top plate portion of the first gate antenna portion 2 and the bottom plate portion of the second gate antenna portion 3 are shared with each other. In addition, coupling through - holes 5 for electromagnetic - coupling the first gate antenna portion 2 and the second gate antenna portion 3 are formed in the top plate portion of the first gate antenna portion 2 and the bottom plate portion of the second gate antenna portion of the shared plate portion 4. That is, since the top plate portion of the first gate antenna portion 2 and the bottom plate portion of the second gate antenna portion 3 are a single conductor plate (shared plate portion 4), the top plate portion of the first gate antenna portion 2 and the bottom plate portion of the second gate antenna portion 3 share one coupling through - hole 5 formed in the shared plate portion 4. Therefore, the first gate antenna portion 2 and the second gate antenna portion 3 are strip - loop antennas each having a pair of openings on both sides, and are electromagnetically coupled through the coupling through - hole 5 of the shared plate portion 4 shared by each other.

[0024] The coupling through - hole 5 is in the shape of a slot extending on the diagonal of the shared plate portion 4. In this embodiment, the coupling through - hole 5 extends on the diagonal of the shared plate portion 4. The shared plate portion 4 is square - shaped. That is, the coupling through-hole 5 extends at an angle of 45° with respect to one side of the shared plate portion 4. Therefore, the coupling through-hole 5 extends while being inclined by 45° with respect to the first opening 2a and the second opening 3a. Each configuration of the first gate antenna portion 2 and the second gate antenna portion 3 is formed of sheet metal.

[0025] In the present embodiment, for example, the first gate antenna portion 2 and the second gate antenna portion 3 are square-shaped with one side being 5.43 mm in a plan view, and the first opening 2a and the second opening 3a have an opening width of 0.5 mm. That is, the first gate antenna portion 2 and the second gate antenna portion 3 have a horizontally long, low-profile, and thin shape in a longitudinal cross-sectional shape. Also, the coupling through-hole 5 has a width of 0.3 mm and a length of 6.0 mm. In the present embodiment, when the wavelength of the electromagnetic wave (incoming wave) to be relayed is λ, the lateral widths of the first openings 2a and the second openings 3a of the first gate antenna portion 2 and the second gate antenna portion 3 are set to approximately λ / 2.

[0026] The directivity of the wireless power relay device 1 of the present embodiment is shown in FIG. 3. Note that the directivity graph shown in FIG. 3 is a simulation of the re-radiation with respect to the wavelength λ of the incoming wave (electromagnetic wave to be relayed) from the z-axis direction in FIG. 1. In the wireless power relay device 1 of the present embodiment, strip loop antennas are arranged vertically and electromagnetically coupled to each other, and the directions of the mutual openings (the first opening 2a and the second opening 3a) are different by 90 degrees in a plan view. Therefore, as shown in FIG. 3, it has directivity in four directions in a cross shape in the zx plane and directivity in two directions in the xy plane, and is re-radiated at the same level in two directions facing each other.

[0027] In this embodiment, when the wavelength of the electromagnetic wave (incoming wave) to be relayed is λ, the lateral widths of the first aperture 2a of the first gate antenna unit 2 and the second aperture 3a of the second gate antenna unit 3 are set to λ / 2. Therefore, the upper and lower first gate antenna units 2 and second gate antenna units 3 have the same resonance frequency, and it is easy to make the gains the same for both the upper and lower units, and the wavelength of the incoming wave to be relayed can be efficiently re-radiated.

[0028] As described above, in the passive relay device 1 of this embodiment, since the coupling through-hole 5 for electromagnetic coupling between the first gate antenna unit 2 and the second gate antenna unit 3 is formed in the top plate portion of the first gate antenna unit 2 and the bottom plate portion of the second gate antenna unit 3 of the shared plate portion 4, when one of the first gate antenna unit 2 and the second gate antenna unit 3 receives a signal, the other is electromagnetically coupled through the coupling through-hole 5, so that the received electromagnetic wave can be transmitted to the other and transmitted in the above two directions and four directions. In addition, since the shared plate portion 4 is a single conductive plate in which the top plate portion of the first gate antenna unit 2 and the bottom plate portion of the second gate antenna unit 3 are shared, it is possible to make the device lower-profile and lighter.

[0029] In addition, since the apertures (the first aperture 2a and the second aperture 3a) of the first gate antenna unit 2 and the second gate antenna unit 3 are arranged to be rotated 90 degrees in plan view, the re-radiation operation can be performed in four directions, and unnecessary radiation can be suppressed. For example, by installing the passive relay device 1 of this embodiment having directivity in four directions at the center of the ceiling at the intersection inside the structure, it becomes possible to efficiently re-radiate in the four passage directions constituting the intersection. In addition, in the passive relay device 1 of this embodiment, since it has a two-stage configuration of the first gate antenna unit 2 and the second gate antenna unit 3 having a rectangular cross-section, it is possible to miniaturize and make the device lower-profile.

[0030] In addition, since the coupling through-hole 5 is in a slot shape extending along the diagonal line of the shared plate portion 4, the first gate antenna portion 2 and the second gate antenna portion 3 can be electromagnetically coupled with high coupling efficiency through the slot-shaped coupling through-hole 5 extending along the diagonal line, enabling signal transmission. That is, when the coupling through-hole 5 extends in a direction parallel to the pair of first openings 2a or the pair of second openings 3a, the coupling efficiency is low, but when it extends in an orthogonal direction, the coupling efficiency is high. In particular, the first gate antenna portion 2 and the second gate antenna portion 3 can be electromagnetically coupled with high coupling efficiency through the slot-shaped coupling through-hole 5 extending along the diagonal line in the middle, allowing signal transmission. Furthermore, since the coupling through-hole 5 extends at an angle of 45° with respect to one side of the shared plate portion 4, re-radiation at the same level is possible in the four opening directions of the pair of first openings 2a and the pair of second openings 3a.

[0031] Next, the second to sixth embodiments of the non-powered relay device according to the present invention will be described below with reference to FIGS. 4 to 14 and FIGS. 17 and 18. In the description of each of the following embodiments, the same components as those described in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0032] The difference between the second embodiment and the first embodiment is that in the first embodiment, the pair of first wall portions 2b and the pair of second wall portions 3b are made of sheet metal, whereas in the non-powered relay device 21 of the second embodiment, as shown in FIGS. 4 and 5, the pair of first wall portions 22b of the first gate antenna portion 22 and the pair of second wall portions 23b of the second gate antenna portion 23 are composed of a plurality of conductive pins P for walls standing side by side along the edge of the shared plate portion 4.

[0033] In this embodiment, the first gate antenna portion 22 and the second gate antenna portion 23 are, for example, square-shaped with a side length of 5.85 mm in plan view. In addition, the plurality of conductive pins P for walls are formed of a metal such as copper and are arranged at a predetermined interval, but it is preferable that the interval between adjacent conductive pins P for walls is narrower.

[0034] Regarding the directivity of the wireless power relay device 21 of the second embodiment, the simulation results similar to those of the first embodiment are shown in FIG. 6. Also in the wireless power relay device 21 of the second embodiment, similar to the first embodiment, it has directivity in four directions in a cross shape in the zx plane and directivity in two directions in the xy plane, and is re-radiated at the same level in two directions facing each other.

[0035] As described above, in the wireless power relay device 21 of the second embodiment, since the first wall portion 22b and the second wall portion 23b are composed of a plurality of wall conductive pins P standing side by side along the edge of the shared plate portion 4, the wall conductive pins P can serve as the side plates of the first wall portion 22b and the second wall portion 23b to form the first gate antenna portion 22 and the second gate antenna portion 23 having a rectangular cross section.

[0036] Next, the difference between the third embodiment and the first embodiment is that in the first embodiment, there is only one wireless power relay device 1 composed of the first gate antenna portion 3 and the second gate antenna portion 4, while in the wireless power relay device 41 of the third embodiment, as shown in FIG. 7, a plurality of unit antennas 41A composed of the first gate antenna portion 2 and the second gate antenna portion 3 are installed with the first openings 2a facing the same direction. In the third embodiment, for example, the unit antennas 41A are arranged in a 4×4 matrix with a mutual interval of 10.8 mm on the same plane.

[0037] Regarding the directivity of the wireless power relay device 41 of the third embodiment, the simulation results similar to those of the first embodiment are shown in FIG. 8. Also in the wireless power relay device 41 of the third embodiment, as shown in FIG. 8, it has strong directivity in four directions in a cross shape in the zx plane and stronger directivity in two directions in the xy plane, and is re-radiated more strongly at the same level in two directions facing each other.

[0038] Thus, in the wireless power relay device 41 of the third embodiment, since a plurality of unit antennas 41A each composed of the first gate antenna unit 2 and the second gate antenna unit 3 are installed with the first openings 2a facing the same direction, the gain can be improved by arraying the unit antennas 41A, and the directivity in the opening directions of the first openings 2a and the second openings 3a can be further amplified to obtain sharp directivity. Therefore, the directivity on the assumed installation surface can be made very small, and it becomes possible to install the device close to a structure. Note that, the larger the number of arrays (installation number) of the unit antennas 41A, the more the gain can be improved.

[0039] Next, the difference between the fourth embodiment and the third embodiment is that, in the third embodiment, the unit antennas 41A are arranged on the same plane, whereas in the wireless power relay device 51 of the fourth embodiment, as shown in FIG. 9, a plurality of unit antennas 41A are respectively installed on a plurality of different planes spaced apart in the vertical direction.

[0040] That is, in the fourth embodiment, for example, a plurality of unit antennas 41A are arranged in a 4×4 matrix on two planes L1 and L2 spaced apart in the vertical direction. Also, the two planes L1 and L2 are set vertically, for example, with a spacing of 21.6 mm from each other. That is, the unit antennas 41A on the plane L2 are arranged directly above the unit antennas 41A on the plane L1 in the same arrangement.

[0041] Regarding the directivity of the wireless power relay device 51 of the fourth embodiment, the simulation results similar to those of the third embodiment are shown in FIG. 10. Also in the wireless power relay device 51 of the fourth embodiment, as shown in FIG. 10, it has strong directivity in four directions in a cross shape in the zx plane and strong directivity in two directions in the xy plane, and is strongly re-radiated at the same level in two directions facing each other.

[0042] Also, regarding the RCS value in the direction of 90° from the zx plane, the frequency characteristics obtained by comparing the non-powered relay device 41 of the third embodiment and the non-powered relay device 51 of the fourth embodiment are shown in FIG. 11. As shown in FIG. 11(a), for the non-powered relay device 41 of the third embodiment in which the unit antennas 41A are arranged in a single layer on a single plane, in the non-powered relay device 51 of the fourth embodiment in which the unit antennas 41A are stacked and arranged on two planes L1 and L2, the gain has increased. Also, as shown in FIG. 11(b), the fifth embodiment in which the antennas are stacked with respect to the third embodiment in which they are arranged in a single layer has hardly changed in the -3dB band.

[0043] As described above, in the non-powered relay device 51 of the fourth embodiment, since a plurality of unit antennas 41A are respectively installed on a plurality of different planes L and L2 spaced apart in the vertical direction, a plurality of unit antennas 41A are stacked in the vertical direction, and it is possible to increase the gain and save space.

[0044] Next, the difference between the fifth embodiment and the fourth embodiment is that in the fourth embodiment, all of the plurality of unit antennas 41A are set to the same operating frequency, whereas in the non-powered relay device 61 of the fifth embodiment, as shown in FIG. 12, the plurality of unit antennas are composed of a first unit antenna 41A and a second unit antenna 61A having different operating frequencies. That is, in the fifth embodiment, the operating frequency f1 of the plurality of first unit antennas 41A arranged on the plane L1 and the operating frequency f2 of the plurality of second unit antennas 61A arranged on the plane L2 are different from each other.

[0045] In the fifth embodiment, for example, the first unit antenna 41A on the plane L1 has a square shape in plan view with a side length of 5.43 mm and an interval of 10.8 mm between them, and the second unit antenna 61A on the plane L2 has a square shape in plan view with a side length of 5.33 mm and an interval of 10.7 mm between them. Regarding the directivity of the wireless power relay device 61 of the fifth embodiment, the results of simulation similar to those of the fourth embodiment are shown in FIG. 13. Also in the wireless power relay device 61 of the fifth embodiment, as shown in FIG. 13, it has strong directivity in four directions in a cross shape in the zx plane and strong directivity in two directions in the xy plane, and is re-radiated strongly at the same level in two opposite directions.

[0046] Further, regarding the RCS value in the direction 90° of the zx plane, the frequency characteristics obtained by comparing the wireless power relay device 41 of the third embodiment with the operating frequency f1, the wireless power relay device 41 of the third embodiment with the operating frequency f2, and the wireless power relay device 61 of the fifth embodiment are shown in FIG. 14. As shown in FIG. 14(a), for the wireless power relay device 41 of the third embodiment in which the first unit antenna 41A with the operating frequency f1 is arranged in a single layer on the same plane, and the wireless power relay device 41 of the third embodiment in which the second unit antenna 61A with the operating frequency f2 is arranged in a single layer on the same plane, in the wireless power relay device 61 of the fifth embodiment in which the first and second unit antennas 41A and 61A with different operating frequencies f1 and f2 are separately stacked and arranged on two planes L1 and L2, the gain is improved. Also, as shown in FIG. 14(b), in the above two third embodiments with single-layer arrangements, there is a band below -3 dB, whereas in the fifth embodiment with a stacked arrangement, it is -3 dB or more, and the frequency band is also expanded.

[0047] Thus, in the wireless power relay device 61 of the fifth embodiment, since a plurality of unit antennas are composed of the first unit antenna 41A and the second unit antenna 61A having different operating frequencies from each other, relay can be performed at different operating frequencies. Also, by separately stacking and arranging the first and second unit antennas 41A and 61A with different operating frequencies f1 and f2 on two planes L1 and L2, the gain can be improved and the frequency band can be expanded.

[0048] Next, the difference between the sixth embodiment and the first embodiment is that in the first embodiment, the shared plate portion 4 is a single conductor plate in which the top plate portion of the first gate antenna portion 2 and the bottom plate portion of the second gate antenna portion 3 are shared with each other, whereas in the wireless power relay device 71 of the sixth embodiment, as shown in FIGS. 17 and 18, the shared plate portion 74 is composed of the top plate portion 72c of the first gate antenna portion 72, the bottom plate portion 73c of the second gate antenna portion 73, and an insulating layer 79 formed of a dielectric between the top plate portion 72c of the first gate antenna portion 72 and the bottom plate portion 73c of the second gate antenna portion 73.

[0049] In the sixth embodiment, the shared plate portion 74 can be manufactured using a printed circuit board process such as a copper-clad laminate composed of, for example, a conductor + dielectric + conductor. That is, in the shared plate portion 74 of the sixth embodiment, the top plate portion 72c of the first gate antenna portion 72 is formed of copper foil on the lower surface of the insulating layer 79 formed of resin, and the portion of the coupling through-hole is pattern-deleted in the same shape as in the first embodiment at the top plate portion 72c of this copper foil to form the coupling through-hole 75A.

[0050] Also, the bottom plate portion 73c of the second gate antenna portion 73 is formed of copper foil on the upper surface of the insulating layer 79, and the portion of the coupling through-hole is pattern-deleted in the same shape as in the first embodiment at the bottom plate portion 73c of this copper foil to form the coupling through-hole 75B. Note that the coupling through-hole 75A and the coupling through-hole 75B have the same shape and face each other. Also, through-holes may be formed in the insulating layer 79 in the same shape as the coupling through-holes 75A and 75B.

[0051] In this embodiment, for example, the first gate antenna portion 72 and the second gate antenna portion 73 are square in plan view with a side length of 5.43 mm, and the first opening 2a and the second opening 3a have an opening width (thickness) of 0.5 mm. That is, the first gate antenna portion 72 and the second gate antenna portion 73 have a horizontally long, low-profile, and thin cross-sectional shape. Further, the coupling through-holes 75A and 75B have a width of 0.3 mm and a length of 6.2 mm. Furthermore, the thickness of the shared plate portion 74 is 0.1 mm.

[0052] The directivity of the wireless power relay device 71 of this embodiment is shown in FIG. 19. Note that the directivity graph shown in FIG. 19 is a simulation of the re-radiation with respect to the incident wave (electromagnetic wave to be relayed) λ from the z-axis direction in FIG. 19. As can be seen from this result, in the wireless power relay device 1 of the first embodiment, it was about -40 dBm2, whereas the wireless power relay device 71 of this embodiment is also re-radiated at a level equivalent to that of the wireless power relay device 1.

[0053] As described above, in the wireless power relay device 71 of the sixth embodiment, the shared plate portion 74 is composed of the top plate portion 72c of the first gate antenna portion 72, the bottom plate portion 73c of the second gate antenna portion 73, and the insulating layer 79 formed of a dielectric between the top plate portion 72c of the first gate antenna portion 72 and the bottom plate portion 73c of the second gate antenna portion 73. Therefore, the top plate portion 72c of the first gate antenna portion 72 and the bottom plate portion 73c of the second gate antenna portion 73 that are close to each other with the dielectric sandwiched therebetween are electromagnetically coupled by the respective coupling through-holes 75A and 75B, and characteristics such as the radar cross section (RCS) can be improved. In addition, the shared plate portion 74 can be easily manufactured using a printed circuit board process such as a copper-clad laminate having a three-layer structure of conductor + dielectric + conductor.

[0054] Note that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

[0055] For example, although the wireless power relay device 21 of the second embodiment is manufactured using sheet metal, it may be manufactured by forming copper foil or the like on a multilayer rigid substrate such as PTFE using a dielectric that is an insulating material such as fluororesin instead of sheet metal. For example, as another example of the second embodiment, as shown in FIG. 15, a wireless power relay device 21B in which a lower rigid substrate 27 and an upper rigid substrate 28 are stacked may be used.

[0056] In this wireless power relay device 21B, similar to the sixth embodiment, the shared plate portion 24B is composed of the top plate portion 22c of the first gate antenna portion 22B, the bottom plate portion 23c of the second gate antenna portion 23B, and an insulating layer 29 formed of a dielectric between the top plate portion 22c of the first gate antenna portion 22B and the bottom plate portion 23c of the second gate antenna portion 23B. That is, the shared plate portion 24B functions as an intermediate rigid substrate.

[0057] In this wireless power relay device 21B, a bottom plate portion 22d of the first gate antenna portion 22B is formed on the lower surface of the lower rigid substrate 27 with a conductor film such as a rectangular copper foil, and a top plate portion 23d of the second gate antenna portion 23B is formed on the upper surface of the upper rigid substrate 28 with a rectangular copper foil. Also, a top plate portion 22c of the first gate antenna portion 22 and a bottom plate portion 23c of the second gate antenna portion 23B are formed on the upper surface of the lower rigid substrate 27 and the lower surface of the upper rigid substrate 28 with a conductor film such as a rectangular copper foil in a state sandwiching the insulating layer 29 to constitute the shared plate portion 24B. Slot-shaped coupling through holes 25B are patterned on the top plate portion 22c of the first gate antenna portion 22B and the bottom plate portion 23c of the second gate antenna portion 23B.

[0058] Furthermore, a plurality of via holes P2 in which conductors such as metal connecting the bottom plate portion 22d and the top plate portion 22c of the first gate antenna portion 22B are embedded are provided in the lower rigid substrate 27 to constitute the first wall portion 22b. Also, a plurality of via holes P2 in which conductors such as metal connecting the top plate portion 23d and the bottom plate portion 23c of the second gate antenna portion 23B are embedded are provided as wall conductor pins in the upper rigid substrate 28 to constitute the second wall portion 23b. Thus, in the wireless power relay device 21B which is another example of the second embodiment and the sixth embodiment, a conductor foil such as copper foil is used instead of sheet metal, and a via hole P2 is used as the wall conductor pin P. Similar to the wireless power relay devices 21 and 71 of the second embodiment and the sixth embodiment, a laminated rectangular cylindrical structure having openings at both ends can be configured.

[0059] Further, as another example of the fourth embodiment, a plurality of the wireless power relay devices 21B are installed with the first openings facing the same direction as unit antennas, and as shown in FIG. 16, a plurality of the wireless power relay devices 21B are installed on a plurality of different planes spaced apart in the vertical direction via spacers S, respectively, whereby a wireless power relay device 51B having the same configuration as the wireless power relay device of the fourth embodiment can be obtained. In this wireless power relay device 51B, by using a large-sized lower rigid substrate 57 and an upper rigid substrate 58, a plurality of wireless power relay devices 21B can be formed as unit antennas in the lower rigid substrate 57 and the upper rigid substrate 58.

[0060] Note that the wireless power relay devices of the above embodiments can operate in the same manner even when installed on a floor. Also, although the coupling conductor pins and the wall conductor pins are all formed of metal bars, they may be vias or through holes as long as they are formed in a pin shape of a conductor such as metal.

Description of Reference Numerals

[0061] 1, 21, 21B, 41, 51, 51B, 61, 71... wireless power relay device, 2, 22, 72... first gate antenna section, 2a... first opening, 2b, 22b... first wall section, 3, 23, 73... second gate antenna section, 3a... second opening, 3b, 23b... second wall section, 4, 24B... common plate section, 5, 25B, 75A, 75B... coupling through hole, 41A... unit antenna, first unit antenna, 61A... second unit antenna, P... wall conductor pin, P2... via hole

Claims

1. A first gate antenna part having a pair of first openings at both ends, formed of a conductor, and having a top plate part and a bottom plate part facing each other vertically and a pair of first wall parts facing each other horizontally, with a rectangular cross-section; A second gate antenna part installed on the first gate antenna part, having a pair of second openings at both ends that open in a direction orthogonal to the opening direction of the first opening in a plan view, formed of a conductor, and having a top plate part and a bottom plate part facing each other vertically and a pair of second wall parts facing each other horizontally, with a rectangular cross-section; The top plate part of the first gate antenna part and the bottom plate part of the second gate antenna part are a rectangular shared plate part integrated with each other; A power-free relay device, characterized in that coupling through-holes for electromagnetically coupling the first gate antenna part and the second gate antenna part to each other are formed in the top plate part of the first gate antenna part and the bottom plate part of the second gate antenna part of the shared plate part.

2. In the power-free relay device according to Claim 1, The power-free relay device, characterized in that the shared plate part is a single conductor plate in which the top plate part of the first gate antenna part and the bottom plate part of the second gate antenna part are shared with each other.

3. In the power-free relay device according to Claim 1, The power-free relay device, characterized in that the shared plate part is composed of the top plate part of the first gate antenna part, the bottom plate part of the second gate antenna part, and an insulating layer formed of a dielectric between the top plate part of the first gate antenna part and the bottom plate part of the second gate antenna part.

4. In the power-free relay device according to any one of Claims 1 to 3, The power-free relay device, characterized in that the coupling through-holes are in a slot shape extending along the diagonal line of the shared plate part.

5. In the power-free relay device according to Claim 4, The shared plate part is square-shaped, The power-free relay device, characterized in that the coupling through-holes extend at an angle of 45° with respect to one side of the shared plate part.

6. In the power-free relay device according to any one of Claims 1 to 5, The power-free relay device, characterized in that the first wall part and the second wall part are composed of a plurality of wall conductor pins standing side by side along the edge of the shared plate part.

7. In the power-free relay device according to any one of Claims 1 to 6, A wireless relay device, characterized in that a plurality of unit antennas each composed of the first gate antenna part and the second gate antenna part are installed with the first openings facing the same direction.

8. In the wireless relay device according to claim 7, A wireless relay device, characterized in that a plurality of the unit antennas are respectively installed on a plurality of different planes spaced apart in the vertical direction.

9. In the wireless relay device according to claim 7 or 8, A wireless relay device, characterized in that the plurality of unit antennas are composed of a first unit antenna and a second unit antenna having different operating frequencies from each other.

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