WO2023074699A1 - 受電アンテナ - Google Patents
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- WO2023074699A1 WO2023074699A1 PCT/JP2022/039768 JP2022039768W WO2023074699A1 WO 2023074699 A1 WO2023074699 A1 WO 2023074699A1 JP 2022039768 W JP2022039768 W JP 2022039768W WO 2023074699 A1 WO2023074699 A1 WO 2023074699A1
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- antenna
- conductive plate
- power receiving
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- receiving antenna
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Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q1/00—Details of, or arrangements associated with, antennas
- H01Q1/36—Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewith
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q13/00—Waveguide horns or mouths; Slot antennas; Leaky-waveguide antennas; Equivalent structures causing radiation along the transmission path of a guided wave
- H01Q13/08—Radiating ends of two-conductor microwave transmission lines, e.g. of coaxial lines, of microstrip lines
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q21/00—Antenna arrays or systems
- H01Q21/28—Combinations of substantially independent non-interacting antenna units or systems
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
- H01Q5/30—Arrangements for providing operation on different wavebands
- H01Q5/307—Individual or coupled radiating elements, each element being fed in an unspecified way
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q7/00—Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01Q—ANTENNAS, i.e. RADIO AERIALS
- H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
- H01Q9/04—Resonant antennas
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J50/00—Circuit arrangements or systems for wireless supply or distribution of electric power
- H02J50/20—Circuit arrangements or systems for wireless supply or distribution of electric power using microwaves or radio frequency waves
- H02J50/27—Circuit arrangements or systems for wireless supply or distribution of electric power using microwaves or radio frequency waves characterised by the type of receiving antennas, e.g. rectennas
Definitions
- Patent Literature 1 and Patent Literature 2 disclose configurations of power receiving antennas for wireless power feeding.
- JP 2016-025502 A Japanese Patent Application Laid-Open No. 2020-184718
- an object of the present disclosure is to provide a power receiving antenna that can efficiently receive power transmitted from a power transmitter located at a certain distance, and that can allow a certain range of sizes.
- a power receiving antenna includes a first conductive plate, a second conductive plate facing the first conductive plate, and a first conductive plate.
- a feeder connecting a first end of the conductive plate of the second conductive plate and a second end of the second conductive plate facing the first end; a first other end on the opposite side of the first end; and a conductive member that connects the two ends with a second other end on the opposite side.
- the conductive member may be a plate-like member that connects the first other end of the first conductive plate and the second other end of the second conductive plate.
- the first conductive plate, the second conductive plate, and the plate-like conductive member may be integrally molded.
- the first conductive plate, the second conductive plate, and the plate-like conductive member may be formed by bending one conductive plate.
- one conductive plate may be configured in a state in which a portion within a predetermined distance from the end is notched.
- the first conductive plate has a stepped central portion in the length direction and protrudes toward the second conductive plate, and the second conductive plate has a central portion in the length direction. It may project stepwise toward the first conductive plate.
- the plate-like conductive plate may be configured in a state in which a portion within a predetermined distance from the end is notched.
- slots may be provided in the first conductive plate and the second conductive plate.
- a protrusion may be provided in which a part of the first conductive plate protrudes toward the second conductive plate from a widthwise end near the center of the first conductive plate.
- a gap may be provided between the tip of the projecting portion and the second conductive plate.
- a power receiving antenna used for wireless power supply can efficiently receive power due to its shape and can supply power to a device or the like to which the power receiving antenna is connected.
- FIG. 1 is a diagram showing a configuration example of an antenna according to the present invention.
- FIG. 2 is an example of a graph showing changes in radiation efficiency according to communication frequencies of the antenna shown in FIG.
- FIG. 3 is an example of a graph showing the transition of the S-parameter according to the communication frequency of the antenna shown in FIG.
- FIG. 4 is an example of a graph showing changes in radiation efficiency according to communication frequencies when the substrate size of the antenna shown in FIG. 1 is changed.
- FIG. 5 is an example of a graph showing changes in radiation efficiency according to communication frequencies of an antenna having a size different from that of the antenna shown in FIG.
- FIG. 6 is an example of a graph showing the transition of the S-parameter according to the communication frequency of an antenna having a size different from that of the antenna shown in FIG.
- FIG. 1 is a diagram showing a configuration example of an antenna according to the present invention.
- FIG. 2 is an example of a graph showing changes in radiation efficiency according to communication frequencies of the antenna shown in FIG.
- FIG. 7 is an example of a graph showing the transition of each S-parameter according to the communication frequency of an antenna having a size different from that of the antenna shown in FIG.
- FIG. 8 is an example of a graph showing the transition of each S-parameter in the vertical direction according to the communication frequency of an antenna having a size different from that of the antenna shown in FIG.
- FIG. 9 is an example of a graph showing changes in radiation efficiency according to communication frequencies of an antenna having a size different from that of the antenna shown in FIG.
- FIG. 10 is an example of a graph showing the relationship between the planar size of the antenna and the radiation efficiency.
- FIG. 11 is an example of a diagram showing a configuration example of an antenna having a configuration different from that of FIG. The upper diagram in FIG.
- FIG. 12 is an example of a graph showing changes in radiation efficiency according to communication frequencies when the height of the antenna is changed.
- the lower diagram of FIG. 12 is an example of a graph showing the transition of the radiation efficiency according to the communication frequency when the width of the antenna is changed.
- FIG. 13 is an example of a diagram showing an antenna pattern (directivity) when the height of the antenna is changed.
- FIGS. 14A to 14F are diagrams showing configuration examples of various antennas.
- FIG. 15 is an example of the antenna shown in FIG. 14(f) and a partially enlarged view thereof.
- FIG. 16 is an example of a graph showing changes in radiation efficiency according to the communication frequency of each antenna shown in FIG.
- FIG. 17 is an example of a diagram showing an antenna pattern (directivity) of each antenna shown in FIG.
- FIG. 18 is an example of a diagram showing that the antenna shown in FIG. 14(f) functions as a composite antenna.
- FIG. 19 is an example of a graph showing the radiation efficiency according to the communication frequency of the antenna when the gap between the projecting portion of the antenna and the second conductive plate shown in FIG. 14(f) is changed.
- FIG. 20 is an example of a diagram showing an antenna pattern (directivity) of the antenna when the gap between the projecting portion and the second conductive plate of the antenna shown in FIG. 14(f) is changed.
- FIG. 21 is an example of a diagram showing a configuration example when the antenna is configured in a spherical shape.
- FIG. 22 is an example of a graph showing radiation efficiency of the antenna shown in FIG. 21 according to communication frequencies.
- FIG. 23 is an example of a diagram showing an antenna pattern (directivity) of the antenna shown in FIG.
- FIG. 24 is an example of a diagram showing a configuration example when the antenna is configured in a columnar shape.
- FIG. 25 is an example of a graph showing the radiation efficiency of the antenna shown in FIG. 24 according to the communication frequency.
- FIG. 26 is an example of a diagram showing an antenna pattern (directivity) of the antenna shown in FIG.
- FIG. 27 is an example of a diagram showing a configuration example of an antenna when a power receiving circuit is provided on one of the conductive plates.
- FIG. 28 is an example of a graph showing the radiation efficiency according to the communication frequency of the antenna shown in FIG. 27.
- FIG. FIG. 29 is an example of a diagram showing an antenna pattern (directivity) of the antenna shown in FIG.
- FIG. 30 is an example of a diagram showing one usage form of the antenna according to this embodiment.
- 31 is an example of an exploded perspective view of the package shown in FIG. 30.
- FIG. FIG. 32 is an example of a diagram showing a basic configuration of an antenna according to Example 2 and a core material applicable therein.
- FIG. 33 is an example of a diagram showing a cross-sectional structure of the first conductive plate in FIG. 32(B).
- FIG. 34 is a diagram illustrating a mounting example of an antenna according to the second embodiment;
- FIG. 35 is an example diagram showing a modification of the antenna and core material applicable therein.
- FIG. 36 is an example of a diagram showing a modification of the 2.4 GHz antenna.
- FIG. 37 is an example of a diagram illustrating a mounting example of feeding power to a sensor using the antenna according to the second embodiment.
- FIG. 38 is an example of a diagram showing a simulation result of radio wave efficiency of two antennas.
- FIG. 39 is an example diagram illustrating an implementation of using an antenna to power a sensor located on a device.
- FIG. 40 is an example of a diagram showing simulation results of reception strengths of two antennas.
- FIG. 41 is an example of a diagram showing a conceptual diagram of efficiently manufacturing a plurality of antennas.
- FIG. 42 is an example of a graph showing changes in impedance (Z parameter) according to the communication frequency of the antenna shown in FIG.
- FIG. 43 is an example of a diagram showing simulation results of the electric field of an antenna.
- FIG. 44 is an example of a diagram showing a conceptual diagram representing the relationship between frequency and impedance.
- a power receiving antenna related to wireless power feeding (wireless power feeding) according to this embodiment will be described below with reference to the drawings.
- the antenna 1 As shown in FIG. 1, the antenna 1 according to the present embodiment has a long plate-like first conductive plate 10a and a long plate-like second conductive plate 10b facing each other, and one end thereof is provided with a feeder. 11 (rectifier) and a conductive member 10c (short pin).
- Antenna 1 is an antenna used in the 920 MHz band for wireless power feeding, but the communication band to be used is not limited to the 920 MHz band, and may be 2.4 GHz or 5.7 GHz. good. In this specification, the communication band used is explained as the 920 MHz band.
- the conductive member 10c is shown as a rod-shaped example in FIG. good too.
- the first conductive plate 10a, the second conductive plate 10b, and the conductive member 10c are realized by an arbitrary material such as copper, aluminum, etc., through which current flows well.
- the feeder 11 is a so-called feeder line, and is provided at one end of the antenna 1 so as to connect the first conductive plate 10a and the second conductive plate 10b. That is, the feeder 11 is connected to the end of the first conductive plate 10a and to the end of the second conductive plate 10b facing the first conductive plate 10a.
- FIG. 1 shows an example in which the conductive member 10c is provided near the feeder 11, but the conductive member 10c is provided at the end opposite to the end where the feeder 11 is provided. is preferably provided.
- the end on the opposite side means the longitudinal direction of the first conductive plate 10a and the second conductive plate 10b when viewed from the end of the first conductive plate 10a and the second conductive plate 10b to which the feeder 11 is connected. means the opposite end of the The reason for this will be described below with reference to FIGS. 2 and 3.
- FIG. 1 shows an example in which the conductive member 10c is provided near the feeder 11, but the conductive member 10c is provided at the end opposite to the end where the feeder
- FIG. 2 shows the radiation efficiency of the antenna 1 when the position of the conductive member 10c is arranged at various positions, and shows the radiation efficiency at each frequency.
- FIG. 3 shows the variation of the S-parameters at each frequency of the antenna 1.
- the antenna 1 is an antenna used as a power receiving antenna in wireless power feeding, and the radiation efficiency is an index indicating how efficiently the power radiated from the radiation source can be received as power.
- the radiation efficiency of the antenna 1 does not greatly depend on the position of the conductive member 10c in the 920 MHz band.
- the horizontal axis indicates the communication frequency
- the vertical axis indicates the radiation efficiency.
- d The radiation efficiency when -16.6667 is 0.90653664
- a radiation efficiency of 0.85 or higher can be ensured in the 920 MHz band.
- the conductive member 10c has the first conductive member 10c at the end opposite to the ends of the first conductive plate 10a and the second conductive plate 10b on which the feeder 11 is provided, in the longitudinal direction. It is preferably provided so as to connect the plate 10a and the second conductive plate 10b.
- FIG. 3 is a graph showing the transition of the S parameter, more strictly the S11 parameter, of the antenna 1 for each frequency band according to the arrangement position from the center of the conductive member 10c.
- the horizontal axis indicates the communication frequency
- the vertical axis indicates the decibel value.
- S11 is the input reflection coefficient for antenna 1; However, the smaller the reflection, the better the efficiency, and the lower the decibel value, the better.
- the reflection coefficient for 50 ohms is simulated, and since it is not 50 ohms when matching with the direct circuit side, it differs from the actual value. If the conductive member 10c is brought close to the feeder 11, the S parameter drops in the 920 megahertz band.
- d -23.3333
- S11 -0.12124553
- d -16.6667
- S11 -0.13121938
- the conductive member 10c and the feeder 11 are separated from each other in the length direction of the first conductive plate 10a and the second conductive plate 10b.
- the antenna 1 is configured to connect the first conductive plate 10a and the second conductive plate 10b at opposite ends. Therefore, in the antenna 1, the first conductive plate 10a and the second conductive plate 10b facing the first conductive plate 10a are separated by a predetermined distance and connected at one end by the feeder 11, and at the other end. It can be said that it is preferable to have a configuration in which the connection is made by the conductive member 10c.
- the distance from the power transmission source to the antenna 1 is 1 m.
- FIG. 5 is a graph showing changes in radiation efficiency according to communication frequencies of antennas of sizes different from those shown in FIG.
- d -6
- the S parameter for .6667 is -0.025784824
- the S parameter shown in the graph of FIG. 6 indicates the reflection loss for 50 ⁇ .
- the S-parameter indicates a lower decibel value, which means a lower reflectance, and is therefore preferable. From the graph of FIG. 6, it can be understood that the antenna in this case is not very favorable for the reflection loss to 50 ⁇ in the 920 MHz band, regardless of the position of the conductive member 10c.
- FIG. 8 is a graph showing the transition of each S-parameter in the vertical direction according to the communication frequency of the same antenna when the distance from the power transmission side is 1 m.
- FIG. 7 (S11, S12, S21, S22) in the 920 MHz band respectively indicated (-46.70311, -21.271524, -21.164399, -42.548009).
- FIG. 8 (S11, S12, S21, S22) in the 920 megahertz band respectively indicate (-67.655771, -58.391212, -64.442047, -87.938023).
- the S parameter (S11) of antenna 1 shows a large negative decibel value under matched conditions, and S21 (transmission characteristics) is improved, It shows that power can be supplied without problems at a distance of 1 m.
- the conductive member 10c is replaced with the first conductive plate 10a provided with the feeder 11 and the second conductive plate
- the radiation efficiency is 0.84695073
- the antenna 1 according to the present invention can be said to exhibit a certain level of performance as a power receiving antenna in wireless power feeding.
- FIG. 11 is a diagram showing a configuration example of an antenna having a configuration different from that of FIG.
- An antenna 1A shown in FIG. 11 shows an example in which the conductive member 10c in the antenna 1 is configured as one conductive plate. That is, in the antenna 1A, a first conductive plate 10a and a second conductive plate 10b are connected at one end by a feeder 11, and at the other end by a conductive plate 10c. showing.
- the first conductive plate 10a, the second conductive plate 10b, and the conductive plate 10c may be formed by individual plates and connected to each other so as to be electrically conductive, or may be formed by bending one conductive plate.
- the conductive plates 10a to 10c may be configured.
- the upper diagram in FIG. 12 is a graph showing the transition of the radiation efficiency according to the communication frequency when the height of the antenna is changed.
- the lower diagram of FIG. 12 is a graph showing the transition of the radiation efficiency according to the communication frequency when the width of the antenna is changed.
- the size of the antenna 1A is as small as possible. Therefore, considering both the size and radiation efficiency, it can be said that the height H2 should be about 5 to 10 mm. The same can be said for the height H1 of the antenna 1 in FIG.
- FIG. 13 is a diagram showing an antenna pattern (directivity) when the height of the antenna is changed.
- the center of the antenna 1 is the origin
- the plane parallel to the first conductive plate 10a and the second conductive plate 10b and passing through the origin is the XY plane
- the short direction of the antenna 1 is the XY plane.
- the longitudinal direction of the antenna 1 (L1 direction in FIG.
- FIG. 13 shows the antenna pattern (directivity) when the areas of the first conductive plate 10a and the second conductive plate 10b of the antenna 1A are fixed and the height H1 is set to 2 mm, 4 mm, 6 mm, 8 mm, and 10 mm. showing.
- the distance between the first conductive plate 10a and the second conductive plate 10b, that is, the height of the antenna 1 is preferably about 10 mm. It can be said that it is preferable to connect the first conductive plate 10a and the second conductive plate 10b at a position as far away from the feeder 11 as possible, that is, at the other end opposite to the end where the feeder 11 is arranged. .
- the size of the first conductive plate 10a and the second conductive plate 10b among the various sizes described above, it can be said that a range centered on 15 mm ⁇ 40 mm is preferable, but any size antenna can be used. Even if there is, if the antenna length is close to 1/4 ⁇ of 920 megahertz in the shapes shown in FIGS.
- FIGS. 14(a) to 14(f) show various variations of the antenna according to the present invention, and show configuration examples of various antennas.
- the base includes a first conductive plate 10a, a second conductive plate 10b, and a conductive plate 10c, as shown in FIG.
- the following description is based on the understanding that the first conductive plate 10a and the conductive plate 10c are arranged in a letter shape and the ends of the first conductive plate 10a and the conductive plate 10c are connected by the feeder 11.
- the antenna 1a shown in FIG. 14(a) is the same as the antenna 1A shown in FIG. FIG. 14 shows it for comparison with other embodiments.
- the antenna 1b shown in FIG. 14(b) is a modification of the antenna 1a.
- the antenna 1b shown in FIG. 14(b) is provided with a convex portion projecting toward the second conductive plate 10b at the center of the first conductive plate 10a of the antenna 1a, and a second conductive plate 10b at the center of the second conductive plate 10b. 1 It has a shape provided with a convex portion protruding toward the conductive plate 10a. That is, the antenna 1b includes a first conductive plate 10a, a second conductive plate 10b facing the first conductive plate 10a, a conductive plate 10c, and a feeder 11. The conductive plate 10c is connected to the first conductive plate 10a.
- One end of the second conductive plate 10b is connected to one end of the first conductive plate 10a facing the first conductive plate 10a, and the feeder 11 connects the other end of the first conductive plate 10a and the first conductive plate of the second conductive plate 10b. The other end facing the other end of 10a is connected.
- An antenna 1c shown in FIG. 14(c) is another modification of the antenna 1a.
- the conductive plates 10a to 10c of the antenna 1a have a shape in which the outer edge portions are left.
- the conductive plates 10a to 10c are formed from a single conductive plate, and the conductive plate in a state in which a predetermined distance is cut from the end of each side is shown in FIG. 14(c). It has a configuration in which the ends are connected by a feeder 11 after being bent so as to be in a state.
- the other end of the plate 10b facing the other end of the first conductive plate 10a is connected.
- An antenna 1d shown in FIG. 14(d) is a frame-shaped antenna obtained by cutting out the inside of the conductive plate 10c in the antenna 1a. That is, the antenna 1d includes a first conductive plate 10a, a second conductive plate 10b facing the first conductive plate 10a, a frame-shaped conductive plate 10c, and a feeder 11.
- the conductive plate 10c One end of the conductive plate 10a and one end of the second conductive plate 10b facing one end of the first conductive plate 10a are connected, and the feeder 11 connects the other end of the first conductive plate 10a and the second conductive plate 10b. It is formed by connecting the other end opposite to the other end of one conductive plate 10a.
- the antenna 1e shown in FIG. 14(e) has a configuration in which slots are further provided in the first conductive plate 10a and the second conductive plate 10b in addition to the antenna 1d. That is, the antenna 1e has a first conductive plate 10a provided with a slot extending in the longitudinal direction and a second conductive plate 10b provided with a slot extending in the longitudinal direction facing each other. It is connected by a feeder 11 and connected by a plate-like conductive member 10c at the other end.
- the antenna 1f shown in FIG. 14(f) further has projections 10d near the center in the longitudinal direction of the first conductive plate 10a toward the second conductive plate 10b from both ends in the W2 direction with respect to the antenna 1e. have a configuration. That is, the antenna 1f has a second conductive plate 10b provided with a slot extending in the longitudinal direction, and a slot extending in the longitudinal direction.
- a first conductive plate 10a having a portion 10d faces each other and is connected at one end by a feeder 11 and at the other end by a plate-like conductive member 10c.
- FIG. 15 is the antenna 1f shown in FIG. 14(f) and a partially enlarged view thereof.
- a protruding portion 10d that protrudes from near the center in the length (L) direction at the end in the width (W) direction of the first conductive plate 10a is the second Although it extends from the first conductive plate 10a toward the conductive plate 10b, it is not connected to the second conductive plate 10b. That is, a predetermined gap is provided between the second conductive plate 10b and the projecting portion 10d.
- the performance of the antenna 1f also varies depending on the length of this gap. This point will be described later with reference to FIG.
- FIG. 16 is a graph showing changes in radiation efficiency according to the communication frequency of each antenna shown in FIG.
- antenna 1f, antenna 1a, antenna 1d, antenna 1b, antenna 1e, and antenna 1c exhibit high radiation efficiency in that order. More specifically, the radiation efficiency of the antenna 1f in the 920 MHz band is 0.99010068, the radiation efficiency of the antenna 1a in the 920 MHz band is 0.93002356, and the radiation efficiency of the antenna 1d in the 920 MHz band is 0.90709889.
- the radiation efficiency of antenna 1b in the 920 MHz band is 0.90532426
- the radiation efficiency of antenna 1e in the 920 MHz band is 0.90475959
- the radiation efficiency of antenna 1c in the 920 MHz band is 0.79928906.
- FIG. 17 is a diagram showing an antenna pattern (directivity) of each antenna shown in FIG. 14.
- each antenna pattern has an elliptical shape with a major axis radius in the direction of 90 degrees and a minor axis radius in the directions of 0 degrees and 180 degrees.
- the short axis radius of the antenna pattern of the antenna 1f is the longest, and the antenna pattern drawn by the antenna 1f is closest to a circle.
- the minor axis radius of the antenna pattern is shorter in the order of antenna 1f, antenna 1e, antenna 1c, antenna 1a, and antenna 1b.
- the antenna shown in FIG. 14 is assumed to be used as a power receiving antenna in wireless power feeding as described above, and as an example, is assumed to be mounted on a small sensor or the like as an IoT device. In this case, since it is not known where the IoT device will be installed, it is preferable that the antenna pattern is such that it can receive radio waves from any direction.
- Antenna 1f is the most preferable antenna pattern among the antennas shown in ⁇ Antenna 1f.
- the shape of the antenna 1f is most suitable as a power receiving antenna used for wireless power feeding.
- the reason why the antenna 1f showed high aptitude will be described with reference to FIG.
- FIG. 18 is a diagram showing that the antenna shown in FIG. 14(f) functions as a composite antenna. 16 and 17, the antenna 1f is considered to be efficient as a power receiving antenna. This is because the antenna 1f functions as a composite antenna as shown in FIG.
- antenna 1f is presumed to function as two loop antennas, two slot antennas, and three dipole antennas. That is, the antenna 1f includes a loop antenna 18g formed around the frame of the conductive member 10c, a loop antenna 18f formed by the first conductive plate 10a, the conductive member 10c, the second conductive plate 10b, and the end of the feeder 11, A slot antenna 18d formed by a slot provided in the first conductive plate 10a, a slot antenna 18e formed by a slot provided in the second conductive plate 10b, a feeder 11-to the center of the first conductive plate 10a- It can be regarded as a composite antenna having parts functioning as six types of antennas, dipole antennas 18a and 18c consisting of the protruding part 10d and dipole antenna 18b consisting of the first conductive plate 10a and the feeder 11. As a result, an excellent It was decided to show the performance of the antenna.
- FIG. 19 is a graph showing the radiation efficiency according to the communication frequency of the antenna when the gap between the projecting portion 10d and the second conductive plate 10b of the antenna shown in FIG. 14(f) is changed.
- the horizontal axis represents the frequency and the vertical axis represents the decibel value. The lower the decibel value, the lower the efficiency.
- FIG. 19 shows the radiation efficiency when the distance (gap) between the projecting portion 10d and the second conductive plate 10b is changed in the range of 0 to 2.48 mm.
- the radiation efficiency differs between when there is no gap (0 mm) and when it is not. I can understand being inferior. More specifically, when the gap was other than 0 mm, the radiation efficiency was around 90% regardless of the gap. Therefore, in the antenna 1f, it is better to provide a gap between the protrusion from the first conductive plate 10a and the second conductive plate 10b.
- FIG. 20 is a diagram showing the antenna pattern (directivity) of the antenna when the gap between the protrusion and the second conductive plate of the antenna shown in FIG. 14(f) is changed.
- FIG. 20 shows examples of antenna patterns with gaps of 0.02 mm, 0.13 mm, 0.2 mm, and 0.6 mm.
- the antenna pattern that is closest to a circle is formed. , the shape of which is close to an ellipse.
- the antenna according to the present embodiment is used as a power receiving antenna in wireless power feeding, and since it is not known where it will be installed at the manufacturing stage, the antenna pattern should be an omnidirectional antenna pattern with as wide a range as possible. is desirable.
- the antenna pattern is the closest to a perfect circle, and (ii) even when the gap is narrower than the gap of 2.48 mm where the radiation efficiency was the best.
- the radiation efficiency is not significantly inferior, and (iii) the antenna pattern with the best radiation efficiency with a gap of 0.6 mm is significantly inferior to the antenna pattern with a narrower gap of 0.13 mm or 0.02 mm.
- 19 and 20 in the case of the antenna 1f, it is better to provide a gap between the projecting portion and the second conductive plate 10b. It can be said that the distance of the gap should be as short as possible so that the antenna pattern formed by the antenna 1f becomes nearly omnidirectional.
- FIG. 21 is a diagram showing a configuration example when the antenna is configured in a spherical shape. More specifically, the antenna shown in FIG. 21 shows an example in which the antenna 1f shown in FIG. As shown in FIG. 21, the antenna 1g is composed of a first conductive plate 10a provided with slots and a second conductive plate 10b provided with slots, which are connected to one another by a frame-shaped conductive member 10c having a cutout inside. , and the feeder 11 connects the other end.
- the first conductive plate 10a, the second conductive plate 10b, and the conductive member 10c are curved in a spherical shape as a whole as illustrated. Further, a plate-like protrusion is provided from the middle of the first conductive plate 10a toward the second conductive plate 10b, and as shown in the figure, this protrusion does not come into contact with the second conductive plate 10b.
- FIG. 22 is a graph showing the radiation efficiency of the antenna shown in FIG. 21 according to the communication frequency.
- the antenna 1g having the shape shown in FIG. 21 exhibits a high radiation efficiency of 0.95751033 in the 920 megahertz band, and can be understood to exhibit sufficient performance as a power receiving antenna.
- FIG. 23 is a diagram showing the antenna pattern (directivity) of the antenna shown in FIG.
- the left diagram of FIG. 23 is a diagram showing the antenna pattern when the antenna 1g is viewed from the top direction, that is, the direction of the arrow 21A shown in FIG. That is, it is a diagram showing the antenna pattern when viewed from the direction of arrow 21B shown in FIG. 21, and the right diagram of FIG. is a diagram showing an antenna pattern of .
- the antenna pattern of the antenna 1g is slightly elliptical in the left and right diagrams of FIG. 23, but has a nearly perfect circular shape. It can be understood that the antenna pattern has an almost ideal shape as an omnidirectional antenna.
- the antenna 1g which is formed by bending the antenna 1f as shown in FIG. 21, can also be used as a power receiving antenna.
- FIG. 24 is a diagram showing a configuration example when the antenna is configured in a columnar shape (annular shape). More specifically, the antenna shown in FIG. 21 is an example in which the antenna 1f shown in FIG. 14(f) is configured in a columnar shape. As shown in FIG. 24, the antenna 1h shows an example in which the antenna 1f is curved in the longitudinal direction to form a columnar shape.
- a plate 10a and a long plate-like second conductive plate 10b curved in the longitudinal direction provided with a slot are each formed into a frame-shaped curved conductive member 10c in which the inside is notched at one end. , and connected by a feeder 11 at the other end.
- FIG. 25 is a graph showing the radiation efficiency of the antenna 1h shown in FIG. 24 according to the communication frequency. As shown in FIG. 25, the antenna 1h having the shape shown in FIG. 24 exhibits a high radiation efficiency of 0.95761551 in the 920 MHz band, and can be understood to exhibit sufficiently high performance as a power receiving antenna.
- FIG. 26 is a diagram showing the antenna pattern (directivity) of the antenna 1h shown in FIG.
- the left diagram of FIG. 26 shows the antenna pattern when the antenna 1h is viewed from the direction of the arrow 24A
- the center diagram of FIG. 26 shows the antenna pattern when the antenna 1h is viewed from the direction of the arrow 24B.
- 26 shows the antenna pattern when the antenna 1h is viewed from the arrow 24C.
- the antenna 1h is circular, it can be said that the antenna 1h is a power receiving antenna that can be used as an omnidirectional power receiving antenna.
- the wireless power supply is more efficient than when the antenna 1f is configured in a box shape as shown in FIG. 14(f). It can be understood that it has a certain aptitude as a power receiving antenna.
- an IoT device equipped with the antenna 1f can be connected to a motion sensor and attached to, for example, a columnar pen holder in a natural manner, in a manner that does not make people conscious of it. can be installed in This IoT device may operate using power received by the antenna 1F, perform sensing, and transmit data obtained by sensing.
- FIG. 27 is a diagram showing a configuration example of an antenna when a power receiving circuit is provided on one of the conductive plates.
- a power receiving circuit is provided on the first conductive plate 10 a , and the power receiving circuit and the second conductive plate 10 b are connected via the feeder 11 .
- FIG. 27 shows an example in which the width of the second conductive plate 10b is narrowed and extended in the direction of the first conductive plate 10a. and the feeder 11 may be connected.
- the antenna 1 By configuring as shown in FIG. 27, the antenna 1 can be easily configured, and the rigidity of the antenna 1 can be improved more than the cases shown in FIGS. 1, 11, and the like.
- the performance of the antenna shown in FIG. 27 will be described with reference to FIGS. 28 and 29.
- FIG. 28 is a graph showing the radiation efficiency of the antenna shown in FIG. 27 according to the communication frequency.
- the radiation efficiency of the antenna shown in FIG. 28 is due to the thinness of the PCB (Printed Circuit Board) including the first conductive plate 10a, power receiving, power storage circuit, sensor, power storage device, and microcontroller.
- Figure 3 shows the radiation efficiency of the corresponding antenna. Specifically, when the combined thickness of the first conductive plate 10a and the PCB is set to 0.3 mm, when the combined thickness of the first conductive plate 10a and the PCB is set to 1 mm, and the first conductive plate 10a and a PCB are bonded together to a thickness of 0.3 mm, three simulations were performed, and the graph showing the radiation efficiency shown in FIG.
- the radiation efficiency of each antenna in the 920 megahertz band is 0.79228273 when the first conductive plate 10a and the PCB are bonded together to a total thickness of 0.3 mm.
- the antenna is 0.62782387 when the combined thickness of the conductive plate 10a and the PCB is 1 mm, and the antenna is 0.3 mm when the first conductive plate 10a and PCB are not bonded and the thickness is 0.3 mm. 59796367, and it can be understood that it was higher in this order.
- FIG. 29 is a diagram showing an antenna pattern (directivity) of the antenna shown in FIG. 27.
- FIG. The antenna pattern shown in FIG. 29 shows the antenna pattern when the antenna shown in FIG. 27 is viewed from the top surface. Therefore, considering FIG. 28 and FIG. 29 together, it is inferred that the first conductive plate 10a of the antenna and the PCB should be adhered together and the thickness should be thin.
- the antenna 1 (1A, 1a to 1h) may be configured as a power receiving antenna for wireless power feeding, and is provided with a capacitor or the like to transmit power from a transmitter. It may be configured as an IoT device that receives and accumulates electric power and supplies it as electric power for operating a sensor or the like. The power received by the antenna 1 may be directly supplied to a sensor or the like, and the sensing data obtained by sensing is transmitted to an external server device or the like using the power received by the antenna 1 from a separate communication circuit. good. At this time, the antenna 1 may be shared as a communication antenna for transmitting and receiving data as long as communication is possible as required.
- FIG. 30 is a schematic diagram showing an example in which the antenna 1 according to this embodiment is casing and formed as an IoT device.
- FIG. 30(a) is an external view of the IoT device
- FIG. 30(b) is an internal perspective view of the IoT device.
- FIG. 31 is an exploded perspective view of the IoT device shown in FIG. 30(a).
- the IoT device may be provided as a box-shaped housing 3000, for example.
- an antenna 1f as an example of the antenna according to the present embodiment and a PCB 3001 provided on the antenna 1f and connected to the antenna 1f are incorporated. showing.
- the housing 3000 is not limited to a box shape as long as the housing 3000 incorporates the antenna 1 and the PCB 3001 inside. It may be spherical.
- FIG. 31 is an exploded perspective view of the housing 3000 exploded.
- a PCB 3001 is provided and connected to the antenna 1f.
- various circuits that implement functions to be implemented as IoT devices such as sensors corresponding to sensing executed as IoT devices, power receiving circuits, power storage circuits, power storage devices, and microcontrollers are mounted.
- the antenna 1f on which the PCB 3001 is mounted is sandwiched between the upper housing 3100 and the lower housing 3101 to form an IoT device.
- the antenna 1 according to this embodiment may be provided as part of an IoT device.
- the antenna 1 When providing it as an IoT device, the antenna 1 with the most appropriate size and high power reception performance according to the size of the IoT device is selected and mounted, thereby realizing the desired function and power from the power transmitter. It is possible to provide an IoT device that can continue to operate as long as it can receive power. In the case of this IoT device, there is no need to install a large battery that is required to operate the IoT device, so the size can be made relatively small and by installing a large battery An accompanying cost increase can be suppressed.
- FIG. 31 shows a mode in which a slot is also provided in the PCB in accordance with the antenna 1f, the PCB may not be provided with the slot.
- the antenna 1 may have a variable structure.
- the antenna length may be changed by a structure in which the conductive member 10c and the feeder 11 are made of an elastic member (for example, a member that can be expanded and contracted by a slide mechanism or the like) to change the length.
- a power receiving antenna according to the present invention efficiently receives power transmitted from a power transmitter at a certain distance (for example, 1 m, but not limited to 1 m, and may be 1 m or more). can.
- the power receiving antenna according to the present invention can have a smaller planar area than a planar loop antenna that is often used for general wireless power feeding, and is provided as a power receiving antenna that is easy to use for IoT devices equipped with a sensor device. be able to.
- the antenna according to the present embodiment is changed to various sizes, it is possible to obtain a certain or more radiation efficiency. However, it can be provided as an antenna having a certain or higher power receiving performance.
- the antenna according to the present embodiment is an antenna having a radiation pattern in which the directivity is approximately 0dbi in all directions. , can receive power and operate anywhere as long as there are no objects interfering with wireless power transmission.
- Antenna 1A shown in FIG. 11 may be treated as an inverted F antenna, for example.
- the first conductive plate 10a becomes the antenna element
- the second conductive plate 10b becomes the ground for the first conductive plate 10a
- the conductive plate 10c becomes the short circuit.
- the first conductive plate 10a is short-circuited to the second conductive plate 10b by the conductive plate 10c.
- the width of the first conductive plate 10a and the width of the second conductive plate 10b as the ground are substantially the same.
- the width of the first conductive plate 10a, the width of the second conductive plate 10b, and the width of the conductive plate 10c are substantially the same.
- the ends of the first conductive plate 10 a and the second conductive plate 10 b opposite to the ends connected by the conductive plate 10 c are connected via the feeder 11 .
- the short-circuit portion and the feeding portion are positioned at a predetermined distance.
- the ends of the first conductive plate 10a and the second conductive plate 10b opposite to the ends connected by the conductive plate 10c are connected through the feeder 11, so that the radiation efficiency, the reflectance, and the directivity are improved. Good simulation results have been obtained for the properties.
- the length L2 of the antenna 1A is, for example, 40 mm to 60 mm, as shown in FIG. This length is, for example, about the same length as 1/4 of the wavelength ⁇ of radio waves in the 920 megahertz band expected to be received by the antenna 1A.
- the equivalent length means, for example, that the numbers have the same number of digits, that is, the difference is less than 10 times.
- the antenna 1A has a length L2 of 40 mm to 60 mm, so that it can efficiently receive radio waves in the 920 megahertz band.
- the characteristic impedance of the first conductive plate 10a, the second conductive plate 10b, and the conductive plate 10c and the characteristic impedance of the feeder 11 are designed to match.
- the characteristic impedance of the first conductive plate 10a, the second conductive plate 10b, and the conductive plate 10c and the characteristic impedance of the feeder 11 are matched using complex conjugate.
- the characteristic impedance of the first conductive plate 10a, the second conductive plate 10b, and the conductive plate 10c is designed to be R+jX.
- the characteristic impedance of the feeder 11 is designed to be R-jX.
- the value of R of the characteristic impedance R+jX of the first conductive plate 10a, the second conductive plate 10b, and the conductive plate 10c is the value of R of the characteristic impedance R ⁇ jX (complex conjugate) of the feeder 11 (such as a rectifier circuit). Ideally equal. Therefore, in order to achieve this, it is necessary to avoid the vicinity of the antenna resonance ( ⁇ /4) and determine the length of the base material that has a common R value at low or high frequencies.
- the antenna 1A Since the antenna 1A has the second conductive plate 10b as a ground, it is possible to prevent the antenna characteristics from being affected by the material of the surface of the member to which it is attached. As a result, the antenna 1A can be placed on a metal surface, the surface of a conductive device or sensor, and usability can be greatly improved.
- FIG. 42 is a diagram showing changes in Z parameter, ie, impedance, at various frequencies of the antenna 1 shown in FIG. FIG. 42 shows simulation results at each frequency of the real part and the imaginary part.
- the upper graph shows the Z parameter according to the communication frequency of the real part
- the lower graph shows the Z parameter according to the communication frequency of the imaginary part.
- the imaginary component is also called reactance.
- the antenna 1 is an antenna that resonates in the 920 MHz band.
- the higher the dB the higher the degree of resonance.
- the antenna length L can be increased by 10 to 30%, preferably by about 20%, to lower the R value and match the desired R value.
- the antenna length L can be shortened by about 10 to 30% from the initial state, and the size of the entire antenna can be reduced. If it falls below the target value specified at this time, that is, the R value is too low and you want to increase it, increase the antenna length L in the low frequency band and increase the antenna length L in the high frequency band. It is possible to adjust the R value by shortening it.
- the ideal length of the antenna is 1/4 wavelength, but it is possible to approach ideal matching by adjusting the antenna length by about ⁇ 20%.
- impedance matching can be achieved with a single component.
- Teflon registered trademark
- the antenna length It is possible to shorten L by about 10 to 30%, preferably about 20%, from the initial state, and it is possible to reduce the size of the entire antenna.
- the conductive member 10c is arranged as far away from the feeder 11 as possible, and if possible, the end opposite to the end where the feeder 11 is provided in the first conductive plate 10a and the second conductive plate 10b It can be said that it is preferable to connect the first conductive plate 10a and the second conductive plate 10b to each other.
- Example 2 In the first embodiment, the power receiving antennas 1, 1A, 1a to 1h of various forms have been described above with reference to FIGS. 1 to 31 and 42. FIG. Next, the antenna 20 according to Example 2 will be described. In the following, to avoid duplication of description, the description of overlapping portions with the antennas 1, 1A, and 1a to 1h according to the first embodiment is omitted.
- FIG. 32 is an example of a diagram showing a basic configuration of an antenna according to Example 2 and a core material applicable therein.
- FIG. 32A there is illustrated a perspective view of the antenna 20 according to Example 2 when viewed from the same direction as the antenna 1A etc. according to Example 1 particularly illustrated in FIG.
- FIG. 32B a perspective view of antenna 20 viewed from the opposite direction is illustrated. From these figures, the basic configuration of the antenna 20 according to the second embodiment can be understood from all sides.
- the antenna 20 illustrated in FIG. 32(A) has a polyhedral shape.
- antenna 20 has a substantially rectangular parallelepiped shape.
- the antenna 20 illustrated in FIG. 32A has a predetermined width direction (X-axis direction) dimension W3, longitudinal direction (Y-axis direction) dimension L3, and height direction (Z-axis direction) dimension H3. have.
- Appropriate adjustments can be made to each dimension, depending on the implementation.
- the dimension H3 in the height direction may be kept relatively small so that the overall posture is low.
- the area obtained from the product of the dimension W3 in the width direction and the dimension L3 in the longitudinal direction may be kept small to minimize the installation area as a whole.
- the antenna 20 exemplified in FIG. 32A has a first conductive plate (conductive member) 21 and a second conductive plate (conductive member) 22, as in Example 1 particularly illustrated in FIG. They are arranged so as to face each other, and are connected to each other via a feeder (rectifier) 25 at one end of each, and via a third conductive plate (conductive member) 23 at the opposite end. connected to each other.
- the first conductive plate 21, the second conductive plate 22, and the third conductive plate 23 are made of any material such as copper, aluminum, etc., through which current flows well. Therefore, a closed current path is formed by the first conductive plate 21, the third conductive plate 23, the second conductive plate 22 and the feeder 25 as indicated by the arrows in FIGS. As illustrated, a loop antenna 50 is formed.
- the loop antenna 50 referred to here is different from a general "loop antenna", but since a loop is formed by the three conductive plates and the feeder 25, it is called a "loop antenna” in this embodiment. call.
- This antenna functions, for example, as a feeding antenna.
- the loop antenna 18f formed by the first conductive plate 10a, the conductive member 10c, the second conductive plate 10b, and the end of the feeder 11 illustrated in FIG. 18 of the first embodiment is a general loop.
- the principle is slightly different from that of an antenna, it is called a "loop antenna” because it forms a loop.
- the directions of the arrows of the loop antenna 50 illustrated in FIGS. 32A and 32B may be reversed.
- the first conductive plate 21 and the second conductive plate 22 are separated from each other by a predetermined distance and extend substantially parallel in substantially the same direction.
- the first conductive plate 21 and the second conductive plate 22 are not limited to being parallel to each other.
- each of the first conductive plate 21, the second conductive plate 22 and the third conductive plate 23 is formed in a long plate shape.
- the first conductive plate 21, the second conductive plate 22, and the third conductive plate 23 can be modified in various lengths and directions of the four sides of the long plate.
- the first conductive plate 21, the second conductive plate 22, and the third conductive plate 23 may be wholly or partially flat, curved, or a combination thereof.
- the third conductive plate 23 is connected to the first conductive plate 21 and the second conductive plate 22 so as to be substantially orthogonal.
- the connection angle of the third conductive plate 23 is not limited to 90 degrees, particularly from the viewpoint of efficiency of the loop antenna 50 .
- Example 2 at least one of the first conductive plate 21, the second conductive plate 22, and the third conductive plate 23 is punched to define a hollow space 24 of a predetermined size. be able to.
- the third conductive member 23 may be stamped to define the substantially rectangular hollow space 24 at an arbitrary location. This hollow space can be sized and shaped so that an inverted-F antenna 60 can be mounted therein.
- the antenna 1d illustrated in FIGS. 14(d) and 18 constitutes a loop antenna 18g made up of the periphery of the frame by notching the inside of the conductive plate 10c.
- the inside of the conductive plate 23 is similarly notched, but the main purpose of the punching process is not to form a loop antenna. Therefore, in the second embodiment, the size of the surrounding frame defining the hollow space 24 (also referred to as a cutout or notch), the thickness of the frame, and the like may be different from those in the first embodiment.
- the antenna 20 illustrated in FIGS. 32A and 32B includes a loop antenna 50 composed of a first conductive plate 21, a second conductive plate 22, a third conductive plate 23 and a feeder 25, and a third and an inverted-F antenna 60 positioned within the hollow space 24 of the conductive plate 23 of the .
- the loop antenna 50 and the inverted F-type antenna 60 make it possible to use antenna patterns of two mutually different frequencies. Therefore, the loop antenna 50 and the inverted F-type antenna 60 can be used for different purposes.
- the loop antenna 50 can be used as a power receiving antenna
- the inverted F antenna 60 can be used as a data communication antenna.
- the antenna 20 exemplified in FIGS. 32A and 32B enables the use of two different types of antennas 50 and 60, thereby expanding the range of applications and contributing to the reduction of the antenna design load on the user side. be able to.
- the antenna 20 is suitable for applications based on wireless power transfer.
- Wireless sensor networks require power receiving antennas and data communication antennas. For example, in IoT sensing using wireless power supply, it may be required to simultaneously use two bands, a 920 MHz band for wireless power supply and a 2.4 GHz band for data communication.
- the antenna illustrated in FIGS. 32A and 32B is suitable for application in this field because it can provide these two antennas.
- the antenna 20 according to the second embodiment can integrate these two antennas and can be miniaturized, the antenna, the rectenna and/or the module can be miniaturized. Therefore, it can be widely applied in various fields.
- the first conductive plate 21 and the second conductive plate 22 each have a predetermined width dimension W3 and a predetermined longitudinal dimension. It has a dimension L3 and secures a predetermined area A3 in two-dimensional directions. Using this area A3, it is possible to mount an electronic circuit or the like on the surface of the first conductive plate 21 .
- a printed circuit board may be mounted on the surface of the first conductive plate 21 .
- PCB is a type of substrate, and refers to a printed wiring board (PWB) on which electronic components are attached to make it operable as an electronic circuit.
- PWB printed wiring board
- a specific configuration of the electronic circuit can be arbitrarily selected according to the embodiment.
- the electronic circuit can include, but is not limited to, a power receiving circuit, a power storage circuit, a sensor, a power storage device, and a microcontroller (microcomputer).
- 34A and 34B are diagrams showing examples of mounting the antenna according to the second embodiment.
- 34A and 34B in particular, the electronic circuit layer 44 (see FIG. 33) arranged above the first conductive plate 21 is illustrated more specifically.
- the configuration illustrated in FIGS. 32A and 32B and the configuration illustrated in FIGS. 34A and 34B do not necessarily have to correspond exactly.
- the coverlay 45 illustrated in FIG. 33 can be partially omitted.
- the electronic circuit may be arranged using not only the upper surface of the first conductive plate 21 but also a part of the third conductive plate 23 and/or the second conductive plate 22 (not shown). The description of the coverlay 45 and the like will be given later.
- the antenna 20 exemplified in FIG. 34(A) can be made relatively small due to the wavelength shortening effect when the core material is inserted. can be done. Description of the core material and the like will be given later.
- the antenna 20 can have a size of about 40 mm to about 60 mm with respect to the longitudinal dimension L3 illustrated in FIG. 32(A).
- the thickness of each conductive plate of the antenna 20 can be several millimeters, or about 5 mm to about 8 mm.
- each dimension of the antenna 20 is not limited to the illustrated numerical range.
- the electronic circuitry on top of the antenna 20 can include, for example, a power supply, sensor driving circuitry and/or wireless communication circuitry.
- the power supply voltage is received from the loop antenna 50 (eg, 920 MHz), and the data acquired by the sensor is transmitted by radio waves from the inverted F-type antenna 60 (eg, 2.4 GHz).
- the connection must be made with a wire.
- a PCB electronic circuit
- antenna 20 when constructing the antenna 20, a flexible printed circuit board (FPC: Flexible Printed Circuits) can be used instead of the PCB.
- the FPC is flexible and can be formed using, for example, a thin insulating material (plastic film).
- antenna 20 may be constructed using a two-layer FPC.
- the first layer is configured as a 920 MHz band antenna (loop antenna 50)
- the second layer is configured as a rectifier circuit, power supply, sensor control circuit, wireless communication circuit, and 2.4 GHz band antenna (inverted F type antenna 60).
- PCB or FPC are optionally used to construct antenna 20 that is relatively small and low-profile (reduced height).
- Example 1 As illustrated in FIG. 11 and the like, the first conductive plate 10a, the second conductive plate 10b, and the third conductive plate 10c are configured in a substantially U-shape in cross section, and the inside thereof is hollow. rice field. For this reason, there are advantages in terms of reducing product weight, the number of product parts, product cost, and labor for product processing.
- Example 2 as illustrated in FIGS. It is shaped like a letter and can be hollow inside. In this case, similarly, there is an advantage in that the weight of the product can be suppressed and the performance of the loop antenna 50 can be ensured.
- a rigid core material 30 made of a dielectric material is further inserted between the two parallel conductive plates 21 and 22 to improve the shape and strength of the product, and to achieve the effect of shortening the wavelength.
- the size of the loop antenna 50 is reduced.
- FIGS. 32(A) and (B) illustrate a core material 30 that can be inserted into the antenna-shaped interior illustrated in FIGS. 32(A) and (B).
- Core material 30 may have an external shape that corresponds to the internal shape of antenna 20 .
- the antenna 20 exemplified in FIG. 32(A) is formed as a substantially rectangular parallelepiped as a whole and has a predetermined width dimension W3, longitudinal dimension L3, and height dimension H3.
- the core material 30 illustrated in FIG. 32(C) has a main body 31 that is generally rectangular parallelepiped as a whole and has a predetermined width dimension W4, longitudinal dimension L4 and height dimension H4. have.
- Each dimension W4, L4 and H4 of the core material 30 can be arbitrarily determined so that the inside of the antenna 20 can be filled with the core material 40.
- FIG. In general, when the dielectric constant ( ⁇ , epsilon) of the core material 30 is high, the size of the antenna 20 (out of W3, L3 and H3 is ) can be shortened, and the size of the antenna 20 can be reduced. The effect of this miniaturization is not limited to the dual-band antenna, but is the same for the antenna 20 configured as a single-band antenna. Note that the main body 31 of the core material 30 does not need to be provided over the entire internal shape of the antenna 20 . If necessary, only part of the internal shape of the antenna 20 may be filled with the core material 30 .
- the main body 31 of the core material 30 is not limited to a solid shape. It is possible to perforate the body 31 if desired. A hollow space may be provided inside the main body 31 if necessary. By providing the hollow, the overall weight can be reduced and the power receiving efficiency, that is, the radiation efficiency is improved. Furthermore, the efficiency is improved by devising the shape of the hollow, securing a wide space in the central portion and a narrow space in the tip portion of the antenna. Also, the body 31 of the core material 30 is not limited to a single piece. It may consist of two or more parts, if desired.
- the core material 30 can be configured using acrylic.
- Acrylic is a kind of plastic, and refers to acrylic resin and acrylic fiber. Also called acrylic glass. Acrylic is not only highly transparent and aesthetically pleasing, but also relatively hard. Acrylic is said to be relatively weak against impact, but impact resistance can be increased by increasing the thickness of acrylic.
- the core material 30 can be constructed using polycarbonate.
- Polycarbonate is a kind of plastic, and particularly a material using polycarbonate resin as a raw material.
- the core material 30 can be constructed using polytetrafluoroethylene (PTFE; fluororesin).
- PTFE polytetrafluoroethylene
- Teflon registered trademark
- the material of the core material is not limited to plastic, acrylic, polycarbonate, PTFE, etc. It is possible to use another material having a high dielectric constant. Since Teflon has a low dielectric loss, the use of Teflon improves radiation efficiency compared to other core materials.
- the antennas 20 By forming the antennas 20 uniformly in the width direction, for example, when manufacturing a large number of antennas 20 as illustrated in FIG. 41, production efficiency can be improved.
- a plurality of sets of antennas and circuit boards are formed in parallel on an FPC (see reference numeral 20 of three solid and dashed lines), and the FPC on which these sets of antennas and circuit boards are mounted is wound around a long core material, After that, by cutting the FPC together with the core material for each set of antennas and circuit boards (see one symbol 20 of the solid line), a plurality of antennas 20 can be efficiently manufactured.
- the core material 30 By inserting the core material 30 between the two conductive plates 21 and 22 which are spaced apart from each other in this way, it is possible to improve the maintenance of the shape of the product and the securing of the strength of the product. Furthermore, by inserting the core material 30 inside the antenna 20, the size of the loop antenna 50 can be reduced due to the wavelength shortening effect based on the characteristics of the dielectric. However, inserting the core material 30 inside the antenna 20 may reduce the power reception efficiency of the loop antenna 50 due to dielectric loss caused by the material.
- FIG. 33 is an example of a diagram showing a cross-sectional configuration of the side surface 26 of the first conductive plate 21 of FIG. 32(B).
- the first conductive plate 21 has a multi-layer structure consisting of a plurality of layers 41-45, such as a two-layer FPC.
- a two-layer FPC means that the copper foil used for the circuit has two layers.
- the multilayer structure of the first conductive plate 21 is not limited to the illustrated five layers. Fewer or more multilayer structures are possible.
- the second conductive plate 22 and the third conductive plate 23 can also have a multilayer structure, but their structures can be different from the case of the first conductive plate 21 .
- the third lowest layer 43 of the first conductive plate 21 is an insulating layer.
- the insulating layer is made of a material having particularly excellent electrical insulation, preferably polyimide.
- the fourth bottommost layer 44 of the first conductive plate 21 is a conductive layer.
- This conductive layer is formed of copper foil, for example.
- An electronic circuit is formed by this copper foil, or an electronic circuit, a battery, a sensor, etc. separately molded in this copper thin film is conducted.
- An inverted F antenna 60 can also be molded from the copper foil of layer 44 in a manner connected to this electronic circuit.
- the fifth layer 45 from the bottom of the first conductive plate 21 is a coverlay. Note that the material of the layers 42 and 44 is not limited to copper, and may be other conductive members.
- the layer 44 of the electronic circuit arranged above the first conductive plate 21 and the layer 42 of the loop antenna 50 arranged below it are insulated from each other by the insulating layer 43 except for some contact points. there is Therefore, even if the electronic circuit is laminated above the first conductive plate 21, the function of the loop antenna 50 formed by the same first conductive plate 21 is not impaired.
- a loop antenna 50 is formed by the copper foil of the layer 42 of the two-layer FPC, and an inverted F antenna 60 is formed by the copper foil of the layer 44, and the layers 43 of polyimide are insulated between them. The antennas can be driven independently, and the performance of each antenna is maintained.
- the antenna for wireless communication can be configured as a pattern antenna on the PCB.
- a large area is required in two dimensions.
- the antenna 20 when configuring the loop antenna 50 along the side surfaces of the conductive plates 21, 22 and 23 extending in a substantially U-shape, the conductive plates 21, 22 and 23 By using a part of the area to configure an antenna for a data communication band (for example, the inverted F-type antenna 60), the overall size of the antenna is reduced. As a result, since the pattern antenna on the same plane as the circuit board is not required, the upper surface of the first conductive plate 21 can be used more widely.
- FIG. 35 is an example diagram showing a modification of the antenna and core material applicable therein.
- the shape of the loop antenna 50 is based on the external shape of the conductive plates composed of the first conductive plate 21 , the second conductive plate 22 and the third conductive plate 23 .
- the first conductive plate 21 and the second conductive plate 22 extend substantially parallel to each other, and are substantially separated from each other by the third conductive plate 23 on the end side. They were connected at an angle of 90 degrees. A loop antenna's performance can be affected by this shape.
- the first conductive plate 21 and the second conductive plate 22 are separated from each other by 90 degrees by the third conductive plate 23 on the end side. are connected at large angles and to have more angles.
- the third conductive plate 23 is bent into a polygonal shape, as indicated by reference numerals 26 and 27.
- FIG. At opposite ends, the first conductive plate 21 and the second conductive plate 22 are likewise bent into polygonal shapes, as illustrated at 28 and 29 . Therefore, the antenna 20 as a whole has a substantially octagonal body when viewed in cross section. Therefore, the shape of the loop antenna 50 is changed from the substantially rectangular shape illustrated in FIGS. 32A and 32B to the substantially octagonal shape illustrated in FIGS. 35A and 35B.
- the first conductive plate 21 and the second conductive plate 22 extend substantially parallel to each other, and are separated from each other by the third conductive plate 23 on the end side. It is connected in a curved shape (or an arc shape).
- the third conductive plate 23 may extend in a curved shape (an arc shape) as a whole.
- the third conductive plate 23 extends partially curved at both ends and partially straight at the center. may
- the surface be flat.
- the bottom surface of the second conductive plate 22 is used as an installation surface for the antenna 20, it is preferable that the surface be flat.
- the third conductive plate 23 has a relatively high degree of freedom in shape, it is possible to change the shape of the loop antenna 50 by modifying its shape.
- the third conductive plate 23 can have any shape to ensure suitable loop antenna 50 performance.
- the third conductive plate 23 may extend entirely straight as illustrated in FIGS. 35(A) and 35(B), it may extend in a polygonal shape as a whole.
- FIGS. 36A to 36D show modifications of the inverted F antenna 60 shown in FIGS. 32A and 32B.
- the inverted F-shaped antenna 60 is mainly composed of a feeder line 61, a short-circuit line 62, and a body portion 63.
- the power supply line 61, the short-circuit line 62, and the body portion 63 are each adjustable in thickness, length, position, shape, etc. according to the embodiment.
- the thicknesses of the feeder line 61, the short-circuit line 62, and the body portion 63 may be adjusted.
- the length of the body portion 63 may be adjusted.
- the height of the body portion 63 may be adjusted.
- the relative position of the short-circuit wire 62 with respect to the feeder wire 61 may be adjusted.
- an inverted F-shaped antenna 60 can have a main body 63 formed in a simple line shape (monopole antenna shape).
- an inverted F-shaped antenna 60 has a body portion 63 that is bent inward at approximately 90 degrees from the state shown in FIG. (see reference numeral 64).
- the inverted F-shaped antenna 60 can be configured such that the body portion 63 is further bent inward at approximately 90 degrees from the state shown in FIG. 36(B) (reference numeral 65 reference).
- the inverted F-shaped antenna 60 can be configured such that the main body portion 63 is bent in a meander line shape instead of forming the main body portion 63 in a simple line shape (not shown). In this way, the inverted F-type antenna 60 can adjust the body portion 63 into various shapes. At that time, the body portion 63 may extend straight, may be bent inward once or a plurality of times, or may be bent inward and outward once or a plurality of times (for example, in a meandering shape). fold). The angle at which the body portion 63 is bent is not limited to 90 degrees.
- the inverted F-shaped antenna 60 may be arranged in a hollow space provided on the bottom surface (second conductive plate 22) of the rectangular parallelepiped antenna shape (not shown). Further, the inverted-F antenna 60 may similarly be placed on any face when the antenna 20 is formed in the shape of a polyhedron having more sides than a rectangular parallelepiped. It should be noted that in the illustrated embodiment, the hollow space 24 has the shape of a square frame. However, the hollow space 24 is not limited to a rectangular shape and can have any shape as long as an inverted F antenna can be mounted therein and the characteristics of the loop antenna 50 can be maintained.
- the antenna 20 may be a chip antenna (not shown) instead of installing the inverted F-type antenna 60 at an arbitrary location.
- a chip antenna is a chip-type component that has the function of transmitting and receiving a required frequency signal, and can be configured particularly small and thin.
- the antenna 20 according to Example 2 can be configured as a dual band antenna including the loop antenna 50 and the chip antenna.
- the antenna 20 can also use other antennas of any shape having similar characteristics.
- the inverted F-type antenna 60 or chip antenna can be mounted anywhere on the side or top of the antenna 20 .
- the top surface of the antenna 20 should have a footprint for the electronic circuitry (PCB or FPC) as described above. Therefore, when the inverted F-shaped antenna is attached to the upper surface of the antenna 20, the size of the upper surface may be increased by that amount compared to the case of attaching to the side surface.
- the area of A3 can be approximated as L3 ⁇ W3.
- the rectangular parallelepiped antenna shape when an inverted F-shaped antenna or a chip antenna is attached to the upper surface of a rectangular parallelepiped antenna, the rectangular parallelepiped antenna shape is more preferable in order to secure the installation area for the electronic circuit (see area A5). It is elongated.
- the rectangular parallelepiped antenna shape has dimensions of length L5, width W5, and height H5. I am letting Note that the value of width W3 may be increased to W5.
- the value of A5 is approximately the same as the value of A3.
- the antenna 20 preferably has a substantially rectangular parallelepiped main body and has a substantially U-shaped cross section.
- This substantially U-shaped shape can include any mode in which the first conductive plate 21 and the second conductive plate 22 are connected by the third conductive plate 23 .
- this substantially U-shaped form includes a straight form of the third conductive plate 23 connecting the first conductive plate 21 and the second conductive plate 22 (see FIG. 32(A)), A substantially polygonal shape (see FIG. 35A) and a substantially curved shape (arc shape) shape (see FIG. 34A) are included.
- antenna 20 may be configured as a dual band antenna including loop antenna 50 and a chip antenna. Furthermore, it is also possible to configure the antenna 20 according to the second embodiment as a single band antenna. In this case, the antenna 20 may be configured to include only the loop antenna 50 .
- the antenna 20 according to the second embodiment may be configured as a multi-band antenna to achieve three or more bands simultaneously.
- slot antennas 18d and 18e may be added to the loop antenna 50 and the inverted F-type antenna 60.
- FIG. Alternatively, other loop antennas may be added to the loop antenna 50 and the inverted F-type antenna 60 .
- linear antennas such as monopole antennas and dipole antennas may be added to the loop antenna 50 and the inverted F-type antenna 60 .
- the antenna 20 can receive one or more bands, and can be configured as an antenna, rectenna, or circuit module (eg, antenna module, sensor module, etc.).
- circuit module eg, antenna module, sensor module, etc.
- FIG. 37 is a diagram illustrating a mounting example of feeding power to a sensor using the antenna according to the second embodiment;
- the left side shows a transmitter 70 with a transmitting function surrounded by a dotted line
- the right side shows a receiver 80 with a receiving function surrounded by a dotted line.
- the transmitter 70 and the receiver 80 are separated from each other by a predetermined distance.
- transmitter 70 and receiver 80 are separated from each other by a distance of about 1 m.
- the charge is about 1 mW to 3 mW, or the charge is about 1 mW to 2 mW.
- this numerical range is exemplary only.
- the transmitter 70 functions as a device on the power transmission side during wireless power supply.
- Oscillator 71 oscillates a signal at a predetermined frequency. This signal may be amplified to remove unwanted frequency components, if desired.
- the transmitting antenna 72 radiates radio waves to the outside.
- the transmitting antenna 72 is controlled by a microcomputer (controller) 73 .
- a microcomputer (controller) 73 controls transmission of the transmitting antenna 2 based on the data received via the data transmitting/receiving antenna 75 and the feedback signal from the data transmitting/receiving device 74 .
- the receiver 80 functions as a device on the power receiving side during wireless power feeding.
- the antenna 20 illustrated in FIGS. 32 to 36 can be used.
- the receiving antenna 81 (for example, the loop antenna 50 of the antenna 20) receives microwaves for power feeding transmitted from the transmitting antenna 72 to the outside.
- loop antenna 50 can function as a power receiving antenna for the 920 MHz band.
- a rectifier 82 (for example, part of PCB or FPC) rectifies the received radio wave and converts it into a rectified voltage.
- a power manager 83 eg, part of the PCB or FPC controls the charging voltage based on the rectified voltage.
- the charging voltage charges, for example, a battery mounted on a part of a PCB or FPC.
- the status of the power management unit 83, the status of the sensor 86, the information acquired by the sensor 86, and the like are continuously or intermittently monitored by the microcomputer 85, and the signal indicating the status and the information acquired by the sensor 86 are stored as data.
- the signal is transmitted by the transmitter 87 to the external transmitter 70 via the transmitting/receiving antenna 88 (eg, the inverted F antenna 60 of the antenna 20).
- the inverted F antenna 60 can function as a data communication antenna for the 2.4 GHz band. Note that power (microwaves) for wireless power supply (920 MHz) is sent in one direction, whereas radio waves for data communication (2.4 GHz) can be sent in both directions.
- the antenna 20 is configured as a dual band antenna in which a plurality of antennas are arranged three-dimensionally. At this time, it was confirmed that even if the single band was changed to the dual band, an antenna shape in which the characteristics of both antennas were less deteriorated could be obtained. Therefore, it can be expected that the antenna 20 achieves overall miniaturization and exhibits good antenna performance.
- FIG. 39 is a diagram illustrating an implementation of using an antenna to power a sensor located on a device.
- an antenna 20 is attached to one side of a device 90 indicated by a dotted line so that power can be supplied to a sensor installed on the device 90 .
- This device 90 can be used in place of the sensor 86 illustrated in FIG.
- the loop antenna 50 of the antenna 20 is formed inside the antenna 20, it is devised so that the performance of the antenna is not impaired by the material of the installation surface. Therefore, even if the antenna 20 is attached directly to the metal surface of the device 90, the loop antenna 50 can continue to function.
- the antenna 20 constitutes a power transmission antenna of the first frequency (for example, 918 MHz) by the loop antenna 50 consisting of the first conductive plate 21, the second conductive plate 22 and the third conductive plate 23. ing.
- loop antenna 50 allows power to be supplied to device 90 .
- the antenna 20 constitutes a data communication antenna of a second frequency (for example, 2.45 G) with the inverted F-type antenna 60 .
- the inverted F-type antenna 60 enables transmission of information indicating the state of the device 90 and information measured by a sensor to the outside.
- FIG. 40 is an example of a diagram showing simulation results of reception strengths of two antennas.
- 40(A) and (B) show the device 90 in FIG. 39 with the x-axis direction up and the yz-plane down (that is, the device 90 in FIG. 3 shows the simulation results of the power reception status of each antenna in a three-dimensional space in a rotated state).
- this simulation result corresponds to the electromagnetic field simulation result under ideal conditions (under conditions where there are no obstacles that block the reception of energy), with the distance from the power transmission source to the antenna 20 being 1 m.
- the darker the color the closer the color is from gray to black
- the more favorable the power reception status is.
- the loop antenna 50 could receive energy relatively evenly along the entire length of the antenna 20 composed of the conductive plates 21 , 22 , 23 .
- simulation results are shown for the power reception status of the inverted F-shaped antenna 60 in a three-dimensional space. Note that this simulation result corresponds to the electromagnetic field simulation result under ideal conditions (under conditions where there are no obstacles that block the reception of energy), with the distance from the power transmission source to the antenna 20 being 1 m. In FIG. 40B, similarly, the darker the color (the closer the color is from gray to black), the more favorable the power reception status is. As can be understood from the figure, the inverted F-type antenna 60 is biased toward one end of the antenna 20, and therefore transmits energy over the entire device 90, although it is biased toward one end of its entire length. Confirmed to be able to receive calls.
- the antenna 20 realizes a dual-band antenna of the loop antenna 50 (eg, 918 MHz) and the inverted F-type antenna 60 (eg, 2.45 GHz) by combining the antenna patterns of two frequency bands. ing. Furthermore, the antenna 20 can be configured not only for dual bands, but also for transmitting and receiving radio waves of other frequencies, and configured as a multi-band antenna with three or more bands.
- the antenna 20 integrates two frequency antennas, the loop antenna 50 and the inverted F-type antenna 60 .
- these two antennas are integrally constructed, they function so that the performance of each antenna is not greatly hindered during use.
- the dual-band antenna of this embodiment which is a combination of the loop antenna 50 and the inverted F-type antenna 60, may have higher reception efficiency than the loop antenna 50 and the inverted F-type antenna 60 alone for the following reasons.
- the loop antenna 50 is common to the ground of the power receiving antenna itself, the size of the antenna is increased and the efficiency is improved.
- the antenna 20 by devising the attachment positions of the loop antenna 50 and the inverted F-type antenna 60, the influence of mutual interference between the antennas may be reduced, and the decrease in efficiency of each antenna may be suppressed.
- the efficiency of each antenna can be improved by, for example, adjusting the impedance of each antenna or matching each antenna so that the efficiency of each antenna is appropriate.
- U.S.C. An FL connector, an arbitrary matching circuit, or the like may be used.
- the inverted F-type antenna 60 By installing the inverted F-type antenna 60 at a position far from the feeder 25, the influence of interference can be reduced.
- the power receiving antenna 50 is installed at a position where the current of the power receiving antenna 50 is small (the position of the ⁇ /4 resonance node), the influence of interference can be reduced.
- Antenna 20 can be configured as an antenna including at least a loop antenna 50 in its simplest implementation.
- Antenna 20 may be configured as a single band antenna consisting of loop antenna 50 .
- loop antenna 50 may be further combined with a rectifier (or rectifier circuit 82, etc.).
- An implementation of the antenna 20 may include at least a loop antenna 50 and a rectifier (or rectifier circuit 82) in combination, and the impedance of the antenna may be adjusted for high efficiency. At this time, matching may be performed according to variations in the size and shape of the antenna 20, frequency may be handled, and the like.
- the antenna 20 can be implemented by combining at least the loop antenna 50, the rectifier (or the rectifier circuit 82), the power supply circuit (or the power management 83), and the data communication circuit board (or the microcomputer 85, etc.). . In this case, it can be provided as an antenna module.
- Aspect 5 Furthermore, as a mounting mode of the antenna 20, at least a loop antenna 50, a rectifier (or rectifier circuit 82), a power supply circuit (or power management 83), a data communication circuit board (or microcomputer 85, inverted F antenna 60) , sensors 86 (see FIG. 37) may be constructed. A device 90 or the like may be used instead of the sensor 86 (see FIG. 39).
- a core material 30 may be further combined inside the antenna 20 .
- the size, shape, and characteristics of each antenna may be adjusted in various ways by adjusting the material, size, shape, and the like of the core material.
- the antenna 20 may utilize FPC.
- the present invention provides an antenna, a rectenna, and a circuit module that are capable of receiving one or more bands, are compact and low-profile, and have few restrictions on the installation position. Therefore, it is possible to provide antenna modules, sensor modules, etc. that are compatible with a wide range of small sensing applications.
- Example 1 and Example 2 may be implemented independently of each other, or may be implemented in combination with each other.
- the core material 30, the inverted F-shaped antenna 60, etc. according to the second embodiment can be applied to the power receiving antennas 1, 1A, 1a to 1h according to the first embodiment.
- the description of Example 1 is applicable to Example 2.
- the communication band used for power supply is not limited to the 920 MHz band, and may be, for example, the UHF band. In Europe, the 868 MHz band may be used, and in the United States, the 915 MHz band may be used. . Also, other frequency bands belonging to the UHF band may be used. Also, the communication band for data communication is not limited to the 2.4 GHz band, and a frequency band in the vicinity of 2.4 GHz ( ⁇ 10%) may be used. For example, a band of 2.45 GHz can also be used. Also, a communication band near 5.7 GHz may be used. While a high frequency band is required for high-speed data communication, it is possible to use a low frequency band for power supply compared to data communication.
- the present invention is not limited to the above-described embodiments, and includes various modifications.
- the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations.
- it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment and it is also possible to add the configuration of another embodiment to the configuration of one embodiment.
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Abstract
Description
本出願は、2021年10月26日に出願された「受電アンテナ」と題する国際特許出願PCT/JP2021/039559号の優先権を主張し、その開示はその全体が参照により本明細書に取り込まれる。
本開示は、ワイヤレス給電による電力を受電するための受電アンテナに関する。
本願は上記課題を解決する手段を複数含んでいるが、その一例を挙げるならば、受電アンテナは、第1の導電板と、第1の導電板に対向する第2の導電板と、第1の導電板の第1端部と、第1端部に対向する第2の導電板の第2端部とを接続するフィーダーと、第1端部の反対側の第1他端部と、第2端部の反対側の第2他端部とを接続する導電性部材と、を備える。
本実施形態に係るアンテナ1は、図1に示すように、長尺板状の第1導電板10aと、長尺板状の第2導電板10bとが互いに対向し、その一端部において、フィーダー11(整流器)を介して互いに接続されるとともに、導電性部材10c(ショートピン)により接続されてなる無線給電における受電側の装置に用いられるアンテナである。アンテナ1は、無線給電に係る920メガヘルツ帯にて利用されるアンテナであるが、使用する通信帯域は、920メガヘルツ帯に限定するものではなく、2.4ギガヘルツ、5.7ギガヘルツであってもよい。本明細書においては使用する通信帯域を920メガヘルツ帯として説明する。
第1導電板10aと第2導電板10bは、共に、長さL1、幅W1の平板状の薄板である。図1では、幅W1=15mm、長さL1=40mm、薄板間距離H1=10mmである場合を例に示している。
図12上図は、第1導電板10aと第2導電板10bの長さと幅を固定(例えば、L2=60mm、W2=30mm)し、H2を変動させていった場合のアンテナ1Aの放射効率の推移を示している。図12上図に示されるように、アンテナ1Aにおいて高さH2を長くしていくほど放射効率が高くなっていることが理解できる。ただ、図12上図に示されるように、高さH2が5mmを超えたあたりから、放射効率は横ばいになっていっており、10mm付近では大きな放射効率の向上は望めないことも理解できる。アンテナ1Aとしては、小型の装置にも搭載することを考慮すると、可能であればそのサイズは小さいことが望ましいと言える。そのため、サイズと放射効率との双方を考慮すると、高さH2は、5~10mm程度にするのがよいと言える。なお、この点は、図1のアンテナ1における高さH1についても同様のことが言える。
図17の右側のアンテナパターンは、図14に示す各アンテナを、天面(第1導電板10a側)から見て、上端にフィーダー11が位置するようにして測定したアンテナパターンを示している。即ち、θ=90°としたときのXY平面上のアンテナパターンを示している。天面から見たアンテナパターンは、図14に示す各アンテナのいずれの場合もほぼ真円に近い円を描くことがシミュレーションによりわかった。したがって、天面から見たアンテナパターンについては、いずれのアンテナにも大きな差異はないと言える。
図29は、図27に示すアンテナのアンテナパターン(指向性)を示す図である。図29に示すアンテナパターンは、図27に示すアンテナを天面から見たときのアンテナパターンを示しており、図示するようにいずれの場合も楕円形状をしており、大きな差異はないと言える。
したがって、図28、図29を総合すると、アンテナの第1導電板10aとPCBとは接着した方がよく、厚みは薄い方がよいと推察される。
図42は、図1に示すアンテナ1の各種周波数におけるZパラメータ、即ち、インピーダンスの変化を示す図である。図42は、実部と虚部のそれぞれの各周波数におけるシミュレーション結果を示している。図42において上側のグラフが実部の通信周波数に応じたZパラメータを示しており、下側のグラフが虚部の通信周波数に応じたZパラメータを示している。虚部の成分はリアクタンスとも呼称される。
このときに指定されたターゲット値を下回った場合、すなわちR値が低くなりすぎており、これを高くしたい場合には、低い周波数帯ではアンテナ長Lを長くし、高い周波数帯ではアンテナ長Lを短くすることでR値を調整することが可能である。アンテナの理想の長さは1/4波長であるが、これに対してアンテナ長を±20%程度調整することで理想的なマッチングに近づけることが可能となる。
受信を想定する電波の周波数帯を共振周波数とする長さ、すなわち例えば受信波長λの1/4の長さをアンテナの初期状態とした場合に、低い周波数でインピーダンスマッチングを行うことで、アンテナ長Lを初期状態から10~30%程度、好ましくは20%程度短くすることが可能となり、アンテナ全体の小型化を行うことが可能である。
以上、実施例1では、図1~図31、図42を参照して、様々な形態の受電アンテナ1、1A、1a~1hについて説明した。
次に、実施例2に係るアンテナ20について説明する。
以下、記載の重複を避けるため、実施例1に係るアンテナ1、1A、1a~1hとの重複部分については、その説明を割愛する。
即ち、実施例2に係るアンテナ20は、WPT(ワイヤレス電力伝送:Wireless Power Transmission又はWireless Power Transfer)に基づいて、3次元空間内でワイヤレスに送電されるエネルギーを受電する受電装置として用いることができる。
実施例2に係るアンテナ20は、受電したエネルギーを、センサ、ロボット、機器、PC等の任意の対象物に対して、エネルギーを送電することができる。
実施例2に係るアンテナ20は、アンテナ又はレクテナとして実装することができる。
実施例2に係るアンテナ20は、アンテナ又はレクテナと、関連する電子部品と一体化されたモジュール(アンテナ・モジュール等)として実装することができる。
実施例2に係るアンテナ20は、アンテナ又はレクテナと、関連する電子部品と、送電対象であるセンサ等と一体化されたモジュール(センサ・モジュール等)として実装することができる。
図32は、実施例2に係るアンテナの基本構成及び、その中に適用可能なコア材を示す図の例である。
図32(A)を参照すると、特に図11に例示した実施例1に係るアンテナ1A等と同様の方向から眺めたときの、実施例2に係るアンテナ20の斜視図が例示されている。
図32(B)を参照すると、反対側の方向から眺めたアンテナ20の斜視図が例示されている。これら図によって、実施例2に係るアンテナ20の基本構成が、全周囲から理解できるようになっている。
なお、実施例1に係る受電アンテナ1、1A、1a~1hでは、板厚を省略して、構造が概略的に例示されていた(例えば、図11及び図14(a)~(f)参照)。図32(A)、(B)では、アンテナ20の板厚についてより具体的に例示している。
実施態様に応じて、各寸法には適当な調整をすることができる。例えば、高さ方向の寸法H3を比較的小さく抑えて、全体として低姿勢にしてもよい。また、幅方向の寸法W3と長手方向の寸法L3との積から求められる面積を小さく抑えて、全体として設置面積を最小にしてもよい。
第1の導電板21、第2の導電板22及び第3の導電板23は、銅、アルミ等、電流をよく流す任意の素材から構成されている。
従って、第1の導電板21、第3の導電板23、第2の導電板22及びフィーダー25により、閉じた電流の経路がつくられていて、図32(A)、(B)の矢印に例示するように、ループアンテナ50が形成されている。
好適には、第1の導電板21、第2の導電板22及び第3の導電板23は、それぞれ長尺板状に形成される。なお、第1の導電板21、第2の導電板22及び第3の導電板23は、長尺板状の四辺の長さや方向を様々に修正することは可能である。また、第1の導電板21、第2の導電板22及び第3の導電板23は、全体的又は部分的に、平ら状であってもよく、湾曲状であってもよく、それらの組み合わせであってもよい。
例示した実施例では、第3の導電板23は、第1の導電板21及び第2の導電板22に対して、略直交するようにつなげられている。しかしながら、以下に詳述するように、特にループアンテナ50の効率の観点から、第3導電板23の接続角度は90度に限定されない。
ただし、第1の導電板21、第2の導電板22及び第3の導電板23は、それぞれ個別の導電板により形成されて、互いに通電可能に接続されてもよい。
特に、アンテナ20は、ワイヤレス電力伝送に基づくアプリケーションへの適用に適している。無線センサネットワークでは、電力受信アンテナとデータ通信アンテナとが必要とされている。例えば、無線給電を利用したIoTのセンシングでは、無線給電用の帯域920MHzとデータ通信用の帯域2.4GHzの2つの帯域を同時に利用することが求められることがある。図32(A)、(B)に例示したアンテナは、これら2つのアンテナを提供することができるため、この分野への適用に適している。
例えば、図32(A)、(B)に例示したアンテナ20は、第1の導電板21と第2の導電板22とは、それぞれ、所定の幅方向の寸法W3と、所定の長手方向の寸法L3を有し、2次元方向に所定の面積A3を確保している。この面積A3を利用して、第1の導電板21の表面上に、電子回路等を搭載することを可能にしている。
電子回路の具体的な構成は、実施形態に応じて任意に選択することができる。例えば、電子回路は、受電回路、蓄電回路、センサ、蓄電装置、マイクロコントローラ(マイコン)を含むことができるが、これに限定されない。
以上、図32(A)、(B)を参照して、アンテナ20の基本構造について、概念的に例示した。
図34(A)、(B)の図では、特に、第1の導電板21の上方に配置される電子回路の層44(図33参照)についてより具体的に例示されている。
図32(A)、(B)に例示した構成と、図34(A)、(B)に例示した構成は、必ずしも厳密に対応しなくてもよい。例えば、電子回路の立体的な形状によっては、図33に例示したカバーレイ45は、部分的に省略することができる。また、電子回路は、第1の導電板21の上面だけでなく、第3の導電板23及び/又は第2の導電板22の一部を利用して配置されてもよい(図示略)。カバーレイ45等の説明については、後述される。
例えば、アンテナ20は、図32(A)に例示した長手方向の寸法L3について、凡そ、40mm付近~60mm付近の大きさを有することができる。
また、アンテナ20は、各導電板の板厚として、数mmの大きさ、又は5mm付近~8mm付近の大きさを有することができる。
ただし、アンテナ20の各寸法は、例示した数値範囲に限定されない。
デュアル・バンド・アンテナとしてアンテナ20を構成する場合、ループアンテナ50(例えば、920MHz)から電源電圧を受信し、逆F型アンテナ60(例えば、2.4GHz)からセンサによる取得データの電波送信を行うことが考えられる。この際、接続はワイヤーで行う必要がある。このように、アンテナ20の上にPCB(電子回路)を設ける場合、その厚みの分、高さ方向の寸法の増加が想定できる。
例えば、アンテナ20は、2層FPCを用いて構成されてもよい。このうち、第一層を920MHz帯アンテナ(ループアンテナ50)とし、第二層を整流回路、電源、センサ制御回路、無線通信回路、2.4GHz帯アンテナ(逆F型アンテナ60)として構成することができる。
PCB又はFPCを任意に用いることで、比較的に小型で、かつ低姿勢(高さを抑えた)アンテナ20を構成するのが好ましい。
実施例1では、図11等に例示したように、第1導電板10a、第2導電板10b及び第3導電板10cは、断面視で略コ字状に構成され、その内部を中空にしていた。このため、製品の重量、製品の部品点数、製品のコスト及び製品の加工の手間の抑制という観点からは長所があった。
実施例2においても同様に、図32(A)、(B)に例示したように、第1の導電板21、第2の導電板22及び第3の導電板23は、断面視で略コ字状に構成され、その内部を中空にすることができる。この場合、同様に、製品の重量等の抑制の他、ループアンテナ50の性能の確保の面で、利点がある。
そこで、実施例2では、さらに、2つの並行の導電板21、22間に誘電体から成る剛性のコア材30を挿入することで、製品の形状や強度の向上を図るとともに、波長短縮効果によるループアンテナ50の小型化を図っている。
例えば、図32(A)に例示したアンテナ20は、全体として略直方体に形成され、所定の幅方向の寸法W3、長手方向の寸法L3及び高さ方向の寸法H3を有している。
図32(C)に例示したコア材30は、同様に、その本体31を全体として略直方体に形成して、所定の幅方向の寸法W4、長手方向の寸法L4及び高さ方向の寸法H4を有している。
なお、コア材30の本体31は、アンテナ20の内部形状の全域にわたって設けられる必要はない。必要に応じて、アンテナ20の内部形状の一部にのみコア材30が充填されるようにしてもよい。
また、コア材30の本体31は、単一部品に限定されない。必要に応じて、2つ又は複数の部品から構成されていてもよい。
例えば、コア材30は、プラスチックを用いて構成することができる。プラスチックとは、誘電体の一種である。プラスチックは、可塑性のある有機高分子物質のことであり、合成樹脂と呼ばれることもある。プラスチックは、複雑な形に加工しやすく、かつコストが安い為、大量生産に有利な素材である。
他には、コア材30は、ポリテトラフルオロエチレン(PTFE;フッ素樹脂)を用いて構成することができる。例えば、コア材30は、テフロン(登録商標)を用いて構成することができる。
他には、コア材の素材はプラスチック、アクリル、ポリカーボネート、PTFE等に限定されず、高い誘電率を有する別の素材を用いることが可能である。
なお、テフロンは誘電損失が少ないため、他のコア材と比べてテフロンを用いると、放射効率が向上する。
さらに、アンテナ20の内部にコア材30を挿入することで、その誘電体の特性に基づいて、波長短縮効果によって、ループアンテナ50のサイズの小型化を図ることができる。ただし、アンテナ20の内部にコア材30を挿入すると、その物質による誘電損により、ループアンテナ50の電力受信効率が低下する可能性がある。
図33から理解できるように、第1の導電板21は、複数の層41~45から成る多層構造を有し、例えば2層FPCである。2層FPCとは、回路に用いる銅箔が2層という意味である。
なお、第1の導電板21の多層構造は、例示した5層に限定されない。これより少ない数又はこれより多い数の多層構造とすることは可能である。また、第2の導電板22と第3の導電板23についても多層構造とすることができるが、それらの構成は、第1の導電板21の場合とは相違させることができる。
例えば、第1の導電板21の一番下から2番目の層42は、導電層である。この導電層は、例えば銅箔で形成される。銅箔は、第1の導電板21を形成し、ループアンテナを構成するために用いられる。
例えば、第1の導電板21の一番下から4番目の層44は、導電層である。この導電層は、例えば銅箔で形成される。この銅箔により電子回路が形成され、若しくは、この銅薄に別に成型した電子回路やバッテリー、センサ等が導通される。また、この電子回路に接続される形で、層44の銅箔により逆Fアンテナ60を成型することができる。
例えば、第1の導電板21の一番下から5番目の層45は、カバーレイである。
なお、層42及び層44の材料は、銅に限られず、その他の導電性部材であってよい。
このように、FPCにより、導電板21、23、22と、逆Fアンテナ60と、回路を一体成型し、コア材に巻き付けてループアンテナ50と逆Fアンテナ60を有するデュアルアンテナを形成することで、本実施例のアンテナ20を容易に製造することができる。
また、2層FPCの層42の銅箔でループアンテナ50を形成し、層44の銅箔で逆Fアンテナ60を形成し、それぞれの間がポリイミドの層43で絶縁されているため、それぞれのアンテナが独立して駆動でき、それぞれのアンテナのパフォーマンスが維持されるように工夫している。
図43は、アンテナ20の電界のシミュレーション結果を示す図の例である。同図から理解できるように、導電板21と22の間に垂直方向の電界が生じる。ここで、ループアンテナ50は、保護層45によって外部環境から保護することができる。このため、図32(A)、(B)に例示したアンテナは、例えば、第1の導電板21を上とし、第2の導電板22を下にして配置された場合、その設置面の物質にかかわらず、ループアンテナ50の機能が損なわれることはない。上下を逆にした場合も同様である。
しかしながら、第1の導電板21の上に電子回路のパターンアンテナを構成する場合、その分、2次元方向に大きな面積をとることになる。
例えば、図34(A)、(B)は、図32に対応する実装である。これを参照すると、アンテナ20のうち、第3の導電板23に中空のスペース24を画定して、その中に逆F型アンテナ60を配置している。
いずれの場合であっても、アンテナ20の大きさを小型に保ちながら、第1の導電板21の上面に電子回路(PCB又はFPC)を設けることを可能にしている。特に、1つのFPCにアンテナを一体化する場合、アンテナ20の小型化、組立て工数軽減が可能になる。
図35は、アンテナの変更例及び、その中に適用可能なコア材を示す図の例である。
ループアンテナ50の形状は、第1の導電板21、第2の導電板22及び第3の導電板23から成る導電板の外部形状が基準となっている。図32(A)、(B)に例示した場合では、第1の導電板21と第2の導電板22とは互いに略平行に延在し、端部側で第3の導電板23によって略90度の角度でつなげられていた。ループアンテナの性能は、この形状によって影響を受け得る。
これに対して、図35(A)、(B)に例示した場合では、第1の導電板21と第2の導電板22とは、端部側で第3の導電板23によって90度よりも大きな角度で、かつより多い角を有するようにつなげられている。
従って、ループアンテナ50の形状は、図32(A)、(B)に例示した略四角形状から、図35(A)、(B)に例示した略八角形状へと変えられている。ループアンテナ50の形状を、より円形(又は楕円形)に近づけることで、意匠の幅を広げたり、アンテナの性能向上を期待することができる。
この際、第3の導電板23は、全体的に湾曲状(円弧状)に延在してもよい。又は、特に図34(A)、(B)に例示したように、第3の導電板23は、両端側で部分的に湾曲状に延在し、その中央では部分的にまっすぐに延在してもよい。
このように、実施形態に応じて、好適なループアンテナ50の性能が確保できるように、第3の導電板23は任意の形状を有することができる。例えば、第3の導電板23は、図32(A)、(B)に例示したように、全体的にまっすぐに延在してもよく、図34(A)、(B)に例示したように、全体的又は部分的に湾曲状に延在してもよく、図35(A)、(B)に例示したように、全体的に多角形状に延在してもよい。
例えば、図35(A)、(B)に例示した場合、第1導電板21、第2導電板22及び第3導電板23は全体で略八角形状を有している。この際、第3導電板23は、多段階に曲げ加工されている(符号26、27参照)。これに対応して、第1導電板21と第2導電板22とはそれぞれ端部を内側に向って折り返している(符号28、29参照)。
さらに、第1の導電板21、第2の導電板22及び第3の導電板23は、任意の場所に凸部又は凹部を設けるとともに、それと対応してコア材30の本体31に凹部又は凸部を設けることで、その場所でコア材を係止させるようにして、コア材の保持力を高めてもよい。
図36(A)~(D)は、図32(A)、(B)に例示した逆F型アンテナ60の変形例を示す。
図36(A)に例示するように、逆F型アンテナ60は、主に、給電線61、短絡線62及び本体部63から構成されている。給電線61、短絡線62及び本体部63は、それぞれ、太さ、長さ、位置、形状等について、実施形態に応じて調整可能となっている。
例えば、給電線61、短絡線62及び本体部63の太さを調整してもよい。
例えば、本体部63の長さを調整してもよい。
例えば、本体部63の高さを調整してもよい。
例えば、給電線61に対する短絡線62の相対的な位置を調整してもよい。
例えば、図36(A)に例示するように、逆F型アンテナ60は、本体部63を単純なライン状(モノポールアンテナ状)に構成することができる。
例えば、図36(B)に例示するように、逆F型アンテナ60は、本体部63を単純なライン状に構成する替わりに、図36(A)の状態からさらに内側に略90度で折り曲げるように構成することができる(符号64参照)。
例えば、図36(C)に例示するように、逆F型アンテナ60は、図36(B)の状態からさらに本体部63を内側に略90度で折り曲げるように構成することができる(符号65参照)。
このように、逆F型アンテナ60は、本体部63を様々な形状に調整することができる。その際、本体部63をまっすぐに延在させてもよく、一回又は複数回にわたって内側に折り曲げてもよく、一回又は複数回にわたって内側と外側とに折り曲げてもよい(例えば、メアンダ状に折り曲げる)。本体部63を折り曲げる角度は、90度に限定されない。
図34(A)、(B)、図36(A)~(C)等を参照すると、逆F型アンテナ60は、直方体のアンテナ形状の側面(第3の導電板23)に中空のスペース24を設け、その中に配置されている。
図36(D)等を参照すると、逆F型アンテナ60は、直方体のアンテナ形状の上面(第1の導電板21)に中空のスペース24を設け、その中に配置されている。
さらに、逆F型アンテナ60は、アンテナ20が直方体よりも側面の数が多い多面体形状に形成されるとき、その任意の面に同様に配置されてもよい。
なお、例示した実施形態では、中空のスペース24は、四角形状の枠の形状を有している。しかしながら、中空のスペース24は、その中に逆F型アンテナを取付けることができ、ループアンテナ50の特性を維持できれば、四角形状に限定されず、任意の形状を有することができる。
チップアンテナは、必要な周波数信号を送信・受信する機能を有するチップ型コンポーネントであって、特に、小型かつ薄型に構成することができる。
この場合、実施例2に係るアンテナ20は、ループアンテナ50とチップアンテナとを含むデュアル・バンド・アンテナとして構成することができる。
さらに、アンテナ20は、逆F型アンテナ60、チップアンテナの替わりに、他、同様の特性を有する任意の形状の他のアンテナを用いることも可能である。
例えば、図36(C)を参照すると、長さL3、幅W3、高さH3の各寸法を有する直方体のアンテナ形状の上面のほぼ全域(領域A3参照)が電子回路の設置面積として確保されている。この場合、A3の面積は、L3×W3として近似することができる。
例えば、アンテナ20は、図21に例示した実施例1に係るアンテナ1fと同様に、球状に構成することも可能である。
例えば、アンテナ20は、図24に例示した実施例1に係るアンテナ1fと同様に、柱状に構成することも可能である。
例えば、アンテナ20は、他、多面体形状、三角柱状、多角柱状、円柱状、楕円柱状等、任意の形状に構成することも可能である。
しかしながら、実施例2に係るアンテナ20の形状は、この形状に限定されない。
例えば、アンテナ20は、図14(e)に例示した実施例1に係るアンテナ1eと同様に、第1導電板10a及び/又は第2導電板10bにスロットを設けた構成にすることも可能である。
この際、図18に例示したように、第1導電板10aに設けられているスロットにより形成されるスロットアンテナ18d及び/又は第2導電板10bに設けられているスロットにより形成されるスロットアンテナ18eを備えることも可能である。
実施例2に係るアンテナ20は、デュアル・バンド・アンテナとして構成され、好適には、ループアンテナ50と逆F型アンテナ60とを含む。この場合、ループアンテナ50によって、第1の周波数(例えば920MHz)の電力受信アンテナを構成可能にするとともに、逆F型アンテナ60によって、第2の周波数(例えば2.4GHz)のデータ通信アンテナを構成可能にするのが好ましい。
さらに、実施例2に係るアンテナ20を、シングル・バンド・アンテナとして構成することも可能である。この場合、ループアンテナ50のみを含むようにアンテナ20を構成してもよい。
次に、図37、図38を参照して、上記アンテナ20を用いて、特にセンサに給電して、稼働させる実装例について説明する。
左側に点線で囲んだ送信機能を有する送信機70を示すとともに、右側に点線で囲んだ受信機能を有する受信機80を示している。送信機70と受信機80とは、互いに所定間隔で離間する。例えば、送信機70と受信機80とは、互いに約1mの距離で離間する。
なお、この例では、送受信間距離を1mとしたとき、1mW~3mW程度の充電、又は1mW~2mW程度の充電を想定している。しかしながら、この数値範囲は例示に過ぎない。
受信アンテナ81(例えば、アンテナ20のループアンテナ50)は、送信アンテナ72から外部に送信された給電用のマイクロ波を受信する。例えば、ループアンテナ50は、920MHz帯の電力受信アンテナとして機能することができる。整流器82(例えば、PCB又はFPCの一部)は、受信電波を整流し、整流電圧に変換する。電力管理部83(例えば、PCB又はFPCの一部)は、整流電圧に基づいて充電電圧を制御する。充電電圧により、例えば、PCB又はFPCの一部に実装されているバッテリーが充電される。
なお、センサ86は、PCB又はFPCの一部として回路整形されてもよい。あるいは、センサ86は、PCB又はFPCに外付けして接続されていてもよい。センサ86の種類は、任意であるが、例えば熱センサ、温度センサ、光センサ、湿度センサ、振動センサ、等を用いることができる。
なお、ワイヤレス給電(920MHz)のパワー(マイクロ波)は一方向に送られるのに対して、データ通信(2.4GHz)の電波は双方向に送られることが可能である。
アンテナ20は、金属面に設置して使用できる利点を生かしながら、2つの周波数帯域に対応することができる。従って、設置面の物質の制約を受けづらく、場所を選ばずに使用することが可能なため、特に、センサ・モジュールの小型化への対応を可能にしている。
図38は、図37に例示した使用状況下で、後述する図39で示す、2450MHz(2.45GHz)のデータ用アンテナと、918MHzの給電用アンテナを設ける図39で示す受信アンテナ20の電波効率のシミュレーション結果が例示されている。
図38では、横軸に周波数を示すとともに、縦軸に効率(1を100パーセントとする)を示している。図38の上方には、ループアンテナ50のシミュレーション結果が示され、下方に逆F型アンテナ60のシミュレーション結果が示されている。なお、このシミュレーション結果は、電力の送電元から、上記のように、アンテナ1までの距離を1mとして、理想的な状況下(エネルギの受電を遮る障害物がない状況下)での電磁界シミュレーション結果に相当する。
特に、FA(Factory Automation)への適用時には、センサ86の替わりに機器に対してアンテナ20を適用してもよい。さらには、ビルマネジメントへの適用も可能であって、その場合、社員証等、人体に近い場所に用いられる任意の部材に対してアンテナ20を適用してもよい。
さらに、送電のターゲットは、他、携帯電話、PDA(携帯情報端末)、ワイヤレス・マイク、ワイヤレスUSB、ワイヤレス・シアター、ワイヤレス・テレビ、ワイヤレス・カメラ、ワイヤレス・ヘッドフォン、ワイヤレス・マウス、ワイヤレス・キーボード、ワイヤレス・ルータ、ワイヤレス・プリンタ等でもよい。
図39は、アンテナを用いて、機器に配置されたセンサに給電する実装例を示す図である。
図39を参照すると、点線で示す機器90の一側面に対してアンテナ20を取付けて、機器90に設置されたセンサへの給電を可能にした場合が概念的に例示されている。この機器90は、図38に例示したセンサ86の替わりに用いることができる。
上述したように、アンテナ20のループアンテナ50は、アンテナ20の内側に形成されるため、設置面の物質によってアンテナの性能が損なわれないように工夫されている。このため、機器90の金属面に対して、直接、アンテナ20を取付けた場合であっても、ループアンテナ50は継続して機能することができる。
また、アンテナ20は、逆F型アンテナ60によって、第2の周波数(例えば2.45G)のデータ通信アンテナを構成している。例えば、逆F型アンテナ60によって、機器90に関する状態を示す情報や、センサにより計測された情報を外部に送信可能にしている。
図40(A)及び(B)は、図39における機器90のx軸の方向を上にし、yz面を下に配置した状態(すなわち図39の機器90をy軸周りに90度時計回りに回転させた状態)での、3次元空間内での各アンテナの受電状況についての、シミュレーション結果を示す。なお、このシミュレーション結果は、電力の送電元から、アンテナ20までの距離を1mとして、理想的な状況下(エネルギの受電を遮る障害物がない状況下)での電磁界シミュレーション結果に相当する。
図40(A)では、色が濃くなる程(灰色から黒色に近づく程)受電状況が好適であることを示している。同図から理解できるように、ループアンテナ50は、導電板21、22、23により構成されるアンテナ20の全長に沿って、比較的偏りなく、エネルギーを受電できていることが確認された。
図40(B)では、同様に、色が濃くなる程(灰色から黒色に近づく程)受電状況が好適であることを示している。同図から理解できるように、逆F型アンテナ60は、アンテナ20の一端部側に偏って設けられているため、その全長の一端部側に偏っているものの、機器90の全域にわたってエネルギーを送受電できることが確認された。
なお、本シミュレーションで用いたアンテナの受電パワーの見積もりを行うと、電力送信出力1W、送電距離1mの条件においては、7.26mW、-21.39dB程度の給電が可能であり、バッテリーに対して3.5mW程度の充電が可能であることが推定できた。ただし、この数値は例示に過ぎず、限定的ではないことを理解されたい。
なお、ループアンテナ50単体と逆F型アンテナ60単体よりも、それらを組み合わせた本実施例のデュアル・バンドのアンテナの方が、以下の理由により受信効率が高まる場合がある。
・ループアンテナ50は、受電用アンテナ自身のグランドと共通なので、アンテナサイズが大きくなり効率が改善される。
・また、逆Fアンテナ60については、ループアンテナ50用のために設けた中空のスペース24があり、その切り抜かれたウィンドウの両サイドを電流が通り抜けることにより、放射パターンの改善とわずかな放射効率向上に寄与する。
逆F型アンテナ60は、フィーダー25から遠い位置に設置することで、干渉の影響が低減できる。また、受電アンテナ50の電流が小さくなる位置(λ/4の共振の節の位置)に設置すると、干渉の影響が低減できる。
実施例2に係るアンテナ20は、様々な態様で実装することができる。
態様1
アンテナ20は、その最もシンプルな実装態様として、少なくともループアンテナ50を含むアンテナとして構成することができる。アンテナ20は、ループアンテナ50から成るシングル・バンド・アンテナとして構成することができる。実装態様によっては、ループアンテナ50は、さらに、整流器(又は整流回路82等)と組み合わされてもよい。
アンテナ20の実装態様として、少なくともループアンテナ50と、整流器(又は整流回路82)とを組み合わせて含むとともに、高い効率を得るためには、アンテナのインピーダンスの調整を行うことができる。この際、アンテナ20の寸法、形状のバリエーションによるマッチングの対応や、周波数対応等を行ってもよい。
アンテナ20の実装態様として、少なくともループアンテナ50と、整流器(又は整流回路82)と、電源回路(又は電力管理83)と、データ通信回路基板(又はマイコン85等)を組み合わせて構成することができる。この場合、アンテナ・モジュールとして提供することができる。
実施例3に対して、さらに逆F型アンテナ60を追加してもよい。この際、逆F型アンテナ60は、特に高周波への適用を可能とし、例えば、2.4GHz帯への適用を可能とする。その際、逆F型アンテナ60のアンテナパターン部分を様々に調整してもよい(図36(A)~(C)参照)。また、逆F型アンテナ60の取付け位置を様々に調整してもよい(図36(B)、(D)参照)。逆F型アンテナ60のアンテナパターン部分が適当な形状をとり得るように、任意の様々な調整を行うことができる。
さらに、アンテナ20の実装態様として、少なくともループアンテナ50と、整流器(又は整流回路82)と、電源回路(又は電力管理83)と、データ通信回路基板(又はマイコン85、逆F型アンテナ60)と、センサ86(図37参照)を組み合わせて含む、センサネットワークシステム(又はセンサ・モジュール)を構築してもよい。センサ86の替わりに、機器90等を用いてもよい(図39参照)。
態様1~態様5の各場合で、アンテナ20の内部にさらにコア材30を組み合わせてもよい。その際、コア材の素材、大きさ、形状等を様々に調整することで、各アンテナの大きさ、形状、特性を様々に調整してもよい。その際、アンテナ20は、FPCを利用してもよい。
また、実施例2では、図32~図41、図43を参照して、様々な形態の受電アンテナ20について説明した。
実施例1と実施例2とは、互いに独立して実装されてもよく、又は、互いに組み合わせて実装されてもよい。例えば、実施例2に係るコア材30や、逆F型アンテナ60等は、実施例1に係る受電アンテナ1、1A、1a~1hに適用することができる。同様に、実施例1の説明は、実施例2に対して適用可能である。
また、データ通信用の通信帯域は、2.4GHz帯に限定するものでは無く、2.4GHzの近傍の(±10%)の範囲の周波数帯を用いてもかまわない。例えば2.45GHzの帯域を用いることもできる。また、5.7GHzの近傍の通信帯域を用いても構わない。高速データ通信のために高い周波数帯域が求められる一方、給電には、データ通信と比較して低い周波数帯域を用いることが可能である。
なお、上述の実施例は少なくとも特許請求の範囲に記載の構成を開示している。
10a・・・第1導電板
10b・・・第2導電板
10c・・・導電性部材
10d・・・突出部
11・・・フィーダー
20・・・アンテナ
21・・・第1の導電板
22・・・第2の導電板
23・・・第3の導電板
30・・・コア材
50・・・ループアンテナ
60・・・逆F型アンテナ
Claims (24)
- 第1の導電板と、
前記第1の導電板に対向する第2の導電板と、
前記第1の導電板の第1端部と、前記第1端部に対向する前記第2の導電板の第2端部とを接続するフィーダーと、
前記第1端部の反対側の第1他端部と、前記第2端部の反対側の第2他端部とを接続する導電性部材と、
を備える第1のアンテナ、
を備える無線給電に用いられる受電アンテナ。 - 前記導電性部材は、前記第1の導電板の第1他端部と、前記第2の導電板の第2他端部と、を接続する板状の部材であることを特徴とする請求項1に記載の受電アンテナ。
- 前記第1の導電板と、前記第2の導電板と、板状の前記導電性部材と、は一体成型されていることを特徴とする請求項2に記載の受電アンテナ。
- 前記第1の導電板と、前記第2の導電板と、板状の前記導電性部材とは、1枚の導電板を折り曲げた状態で構成されていることを特徴とする請求項2に記載の受電アンテナ。
- 前記1枚の導電板を、端部から所定距離内を切り欠いた状態で構成されていることを特徴とする請求項4に記載の受電アンテナ。
- 前記第1の導電板は、長さ方向において中央部が段状に、前記第2の導電板に向けて突出しているとともに、
前記第2の導電板は、長さ方向において中央部が段状に、前記第1の導電板に向けて突出している
ことを特徴とする請求項1に記載の受電アンテナ。 - 板状の前記導電板は、端部から所定距離内を切り欠いた状態で構成されていることを特徴とする請求項4に記載の受電アンテナ。
- 前記第1の導電板と前記第2の導電板には、スロットが設けられていることを特徴とする請求項7に記載の受電アンテナ。
- 前記第1の導電板の中央近傍の幅方向の端部から、前記第2の導電板に向けて、前記第1の導電板の一部が突出した突出部を備えることを特徴とする請求項8に記載の受電アンテナ。
- 前記突出部の先端と、前記第2の導電板との間にはギャップが設けられていることを特徴とする請求項9に記載の受電アンテナ。
- 前記第1の導電板と前記第2の導電板との間に誘電体のコア材を充填した、請求項1~10のいずれか1項に記載の受電アンテナ。
- 前記第1の導電板、前記導電性部材、及び前記第2の導電板のうちの少なくとも一つに中空のスペースを設け、その中に第2のアンテナを配置した、
請求項1~10のいずれか1項に記載の受電アンテナ。 - 前記第1のアンテナは、ループアンテナとして機能する、
請求項1~10のいずれか1項に記載の受電アンテナ。 - 前記第1の導電板、前記導電性部材、及び前記第2の導電板は、断面視で略コ字状の形状を有し、前記コの字の内側に前記ループアンテナの電界を生じさせるようにした、
請求項13に記載の受電アンテナ。 - 前記第1のアンテナは、電力受信用のアンテナである、
請求項1~10のいずれか1項に記載の受電アンテナ。 - 前記第1のアンテナは、約920MHzの周波数領域で駆動する、
請求項1~10に記載の受電アンテナ。 - 前記第2のアンテナは、逆Fアンテナ又はチップアンテナのいずれかである、
請求項12に記載の受電アンテナ。 - 前記第2のアンテナは、データの送受信用のアンテナである、
請求項12に記載の受電アンテナ。 - 前記第2のアンテナは、約2.4GHzの周波数領域で駆動する、
請求項12に記載の受電アンテナ。 - 前記第1の導電板と前記第2の導電板との間に誘電体のコア材を充填した、請求項12に記載の受電アンテナ。
- 前記第1の導電板、前記導電性部材、及び前記第2の導電板は、フレキシブルプリント基板(FPC)の第1の導電層により構成され、前記第2のアンテナは逆F型アンテナであり、かつ、前記逆F型アンテナは、前記FPCの第2の導電層により構成される、
請求項12に記載の受電アンテナ。 - 前記第1のアンテナは、逆Fアンテナとして機能する、
請求項1に記載の受電アンテナ。 - 前記第1の導電板の幅と、前記第2の導電板の幅とは、略同一であり、
前記第1の導電板の長さと、前記第2の導電板の長さとは、受信を想定する電波の周波数帯を共振周波数とする長さよりも、10~30%好ましくは20%程度長い、
請求項22に記載の受電アンテナ。 - 前記第1の導電板の幅と、前記第2の導電板の幅とは、略同一であり、
前記第1の導電板の長さと、前記第2の導電板の長さとは、受信を想定する電波の周波数帯を共振周波数とする長さよりも、10~30%好ましくは20%程度短い、
請求項22に記載の受電アンテナ。
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Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6234405A (ja) * | 1985-08-07 | 1987-02-14 | Fujitsu Ltd | 無線機用アンテナ |
JP2001251128A (ja) * | 2000-03-03 | 2001-09-14 | Matsushita Electric Ind Co Ltd | 多周波アンテナ |
JP2003158419A (ja) * | 2001-09-07 | 2003-05-30 | Tdk Corp | 逆fアンテナ及びその給電方法並びにそのアンテナ調整方法 |
JP2007097358A (ja) * | 2005-09-30 | 2007-04-12 | Toshiba Corp | 情報収集装置及び方法 |
WO2013031518A1 (ja) * | 2011-08-26 | 2013-03-07 | エスアイアイ移動通信株式会社 | 板状逆fアンテナ |
JP2016025502A (ja) | 2014-07-22 | 2016-02-08 | 住友電工プリントサーキット株式会社 | ワイヤレス受電用アンテナ及びウエアラブルデバイス |
WO2016129542A1 (ja) * | 2015-02-10 | 2016-08-18 | 株式会社 フェニックスソリューション | Rfタグ用アンテナ及びその製造方法、並びにrfタグ |
JP2020184718A (ja) | 2019-05-09 | 2020-11-12 | パナソニック株式会社 | アンテナ装置 |
-
2021
- 2021-10-26 WO PCT/JP2021/039559 patent/WO2023073817A1/ja unknown
-
2022
- 2022-10-25 WO PCT/JP2022/039768 patent/WO2023074699A1/ja active Application Filing
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6234405A (ja) * | 1985-08-07 | 1987-02-14 | Fujitsu Ltd | 無線機用アンテナ |
JP2001251128A (ja) * | 2000-03-03 | 2001-09-14 | Matsushita Electric Ind Co Ltd | 多周波アンテナ |
JP2003158419A (ja) * | 2001-09-07 | 2003-05-30 | Tdk Corp | 逆fアンテナ及びその給電方法並びにそのアンテナ調整方法 |
JP2007097358A (ja) * | 2005-09-30 | 2007-04-12 | Toshiba Corp | 情報収集装置及び方法 |
WO2013031518A1 (ja) * | 2011-08-26 | 2013-03-07 | エスアイアイ移動通信株式会社 | 板状逆fアンテナ |
JP2016025502A (ja) | 2014-07-22 | 2016-02-08 | 住友電工プリントサーキット株式会社 | ワイヤレス受電用アンテナ及びウエアラブルデバイス |
WO2016129542A1 (ja) * | 2015-02-10 | 2016-08-18 | 株式会社 フェニックスソリューション | Rfタグ用アンテナ及びその製造方法、並びにrfタグ |
JP2020184718A (ja) | 2019-05-09 | 2020-11-12 | パナソニック株式会社 | アンテナ装置 |
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