JP2014165561A - Antenna, communication device, and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an antenna for a circular polarized wave which is small, has wide directivity, enables impedance matching at the antenna side, and to provide a communication device using the antenna and an electronic apparatus.SOLUTION: An antenna 1 includes: a dielectric substrate 10; a first electrode 20; and a second electrode 30. The dielectric substrate 10 includes a first surface 10A and a second surface 10B which face each other. The first electrode 20 has a belt like shape and is formed on the first surface 10A. The second electrode 30 has a belt like shape and is formed on the second surface 10B. When the dielectric substrate 10 is planarly viewed, the first electrode 20 intersects with the second electrode 30. Electric power is supplied to the first electrode 20 and the second electrode 30 in a region where the first electrode 20 and the second electrode 30 are overlapped.

Description

  The present invention relates to an antenna, a communication device, and an electronic device.

  For example, in a navigation device using a satellite mobile phone or GPS (Global Positioning System), wireless communication using circular polarization is performed. Although circularly polarized waves can be received with a linearly polarized antenna, it is desirable to use a circularly polarized antenna because the gain is halved. For example, in a circularly polarized patch antenna having a substantially square radiating electrode and a ground electrode facing each other across a dielectric substrate, a desired circularly polarized wave (right-handed circularly polarized wave or left-handed circularly polarized wave) is generated by the radiating electrode. Can receive and transmit. However, the ground electrode can receive and transmit only circularly polarized waves in a turning direction different from the desired circularly polarized wave. In other words, when the radiation electrode is configured to receive or transmit right-handed circularly polarized waves, the ground electrode can receive or transmit only left-handed circularly polarized waves. As described above, in the circularly polarized patch antenna, reception and transmission of a desired circularly polarized wave is limited to either the space on the surface side where the radiation electrode is provided or the space on the surface side where the ground electrode is provided.

  For this reason, for example, when a circularly polarized patch antenna is installed in a car as a GPS antenna for a car navigation device, the surface provided with the radiation electrode (or ground electrode) always has the zenith direction (the direction in which the artificial satellite exists). Therefore, the reception performance of circularly polarized waves does not fluctuate greatly. However, when a circularly polarized patch antenna is mounted on a mobile device or wearable device as a GPS antenna, the orientation of these devices varies depending on the usage conditions and the surface provided with a radiation electrode (or ground electrode) is always present. Since it does not always face the zenith direction, the reception performance of circularly polarized waves greatly fluctuates. Therefore, as a circularly polarized antenna to be mounted on a mobile device or a wearable device, a small circularly polarized antenna having a wide directivity has been demanded instead of an antenna having a narrow directivity like a circularly polarized patch antenna.

  For example, Patent Document 1 describes a circularly polarized antenna 1 including a quadrangular prism-shaped dielectric base 3 and four radiating conductors 4 provided on each side of the dielectric base 3 so as to be inclined by 45 °. Has been. In the circularly polarized wave antenna 1, when attention is paid to the two radiation conductors 4 provided on the opposite side surfaces, the two radiation conductors 4 are orthogonal to each other. Also, circularly polarized waves are obtained by arranging both radiating conductors 4 generating spatially orthogonal polarized waves at an interval d1 where a phase difference of 90 ° occurs and feeding both radiating conductors 4 in the same phase (summary). Document, Claim 1, Paragraph 0019, FIG. 1, etc.).

JP 2002-246837 A

  However, the circularly polarized antenna 1 described in Patent Document 1 needs to include a matching circuit in order to achieve impedance matching, and impedance matching cannot be achieved on the antenna side.

  The present invention has been made in view of the above-described circumstances, and is a circularly polarized antenna that is small in size, has a wide directivity, and can achieve impedance matching on the antenna side, and a communication apparatus and electronic apparatus using the antenna. It is a solution subject to provide.

  In order to solve the above problems, an antenna according to the present invention includes a dielectric substrate having a first surface and a second surface facing each other, a strip-shaped first electrode provided on the first surface, A band-shaped second electrode provided on a second surface, and when the dielectric substrate is viewed in plan, the first electrode and the second electrode intersect, and the first electrode and the second electrode The first electrode and the second electrode are supplied with power in a region where the two electrodes overlap each other.

According to the above configuration, the first electrode and the second electrode are disposed with the dielectric substrate interposed therebetween. Here, when the dielectric substrate is viewed in plan, the strip-shaped first electrode and the strip-shaped second electrode intersect each other. As a result, the direction of the current flowing through the first electrode and the direction of the current flowing through the second electrode have orthogonal components. Therefore, it is possible to create a state in which the electric field generated from the first electrode intersecting in the far field and the electric field generated from the second electrode have orthogonal components.
Further, by adjusting the thickness of the dielectric substrate, for example, the phase difference between the current supplied to the first electrode and the current supplied to the second electrode is set to 180 ° and generated from the first electrode. The phase of the waveform of the electric field radiated to the second surface side through the dielectric substrate and the waveform of the electric field generated from the second electrode and radiated to the first surface side through the dielectric substrate are set to 90. It is possible to delay by °. Thereby, a phase difference of 90 ° is generated in the waveforms of the two electric fields synthesized in the space on the first surface side and the space on the second surface side.
Thus, in the antenna according to the present invention, two electric fields intersecting in the far field have orthogonal components, and a 90 ° phase difference can be generated between the waveforms of the two electric fields. Can be received or transmitted.

  Moreover, since the antenna according to the present invention uses a dielectric substrate, the antenna can be miniaturized due to the wavelength shortening effect. In addition, the antenna according to the present invention generates a desired circularly polarized wave (right-handed circularly polarized wave or left-handed circularly polarized wave) at substantially the same level in both the space on the first surface side and the space on the second surface side. Since it can be received or transmitted, the directivity is wider than that of a circularly polarized patch antenna. In other words, a desired circularly polarized wave can be received or transmitted by both the first electrode and the second electrode. Furthermore, the antenna according to the present invention has been studied by the inventor. As a result, when the dielectric substrate is viewed in plan, by adjusting the position of feeding both in the region where the first electrode and the second electrode overlap, It was found that impedance matching of the antenna, the feeder line, and the communication circuit (receiving circuit or transmitting circuit) can be achieved. Therefore, impedance matching can be achieved on the antenna side without providing a matching circuit, and the reception loss and transmission efficiency of the antenna can be improved by eliminating reflection loss.

  Therefore, according to the present invention, it is possible to provide a circularly polarized antenna that is small in size, has wide directivity, and can achieve impedance matching on the antenna side.

In the antenna according to the present invention, the first electrode and the second electrode may be orthogonal when the dielectric substrate is viewed in plan.
According to this configuration, since the first electrode and the second electrode are orthogonal to each other, a desired circularly polarized wave (right-handed circularly polarized wave or left-handed circularly polarized wave) out of all received components or all transmitted components of the antenna. Is the highest percentage. Therefore, the reception performance and transmission performance of the antenna can be improved.

In the antenna according to the present invention, the width in the short direction of the first electrode or the width in the short direction of the second electrode may be larger than the thickness of the feeder line.
Power is supplied to the first electrode and the second electrode using a power supply line. For this reason, in order to achieve impedance matching, it is necessary to adjust the connection position of the feeder line in a region where both electrodes overlap in the dielectric substrate. Therefore, impedance matching can be facilitated by making at least the width in the short direction of the first electrode or the width in the short direction of the second electrode larger than the thickness of the feeder line.

In the antenna according to the present invention, a power feeding hole may be formed in one of the first electrode and the second electrode and the dielectric substrate.
If power is supplied through the power supply hole through the power supply hole, the position of power supply to the electrode can be determined more accurately, and impedance matching can be easily achieved.

Further, in the antenna according to the present invention, a portion excluding both ends of the edge extending in the longitudinal direction of the first electrode does not overlap with the edge of the first surface and extends in the longitudinal direction of the second electrode. The structure which does not overlap the edge of the said 2nd surface among the edges which remove | exclude both ends may be sufficient.
For example, the case where both the first electrode and the second electrode are rectangular will be described as an example. The current distribution is not uniform in the first electrode and the second electrode, and a large current flows particularly in the two long sides. . Therefore, if two long sides (edges extending in the longitudinal direction) of each electrode are exposed, the wavelength shortening effect cannot be sufficiently obtained, and the antenna becomes large. Further, current does not flow in the longitudinal direction of the electrodes at both ends of each long side, that is, at the four apex portions of each electrode (rectangle). Therefore, by enclosing the portion excluding both ends of the two long sides of each electrode with a dielectric, a sufficient wavelength shortening effect can be obtained and the antenna can be downsized.

In the antenna according to the present invention, an edge extending in the longitudinal direction of the first electrode does not overlap an edge of the first surface, and an edge extending in the longitudinal direction of the second electrode is the second electrode. The structure which does not overlap with the edge of the surface may be sufficient.
In this way, all the edge portions extending in the longitudinal direction of the first electrode are not overlapped with the edges of the first surface, and all the edge portions extending in the longitudinal direction of the second electrode. May not overlap with the edge of the second surface.

In the antenna according to the present invention, the edge of the first electrode may not overlap the edge of the first surface, and the edge of the second electrode may not overlap the edge of the second surface. Good.
In this way, all the edges of the first electrode may not overlap with the edges of the first surface, and all the edges of the second electrode may not overlap with the edges of the second surface.

In the antenna according to the present invention, the longitudinal direction of the first electrode is not parallel to any side of the first surface, and the longitudinal direction of the second electrode is parallel to any side of the second surface. It may be a configuration that is not.
For example, the case of the first surface and the first electrode will be described as an example. If the outer shape of the first surface is a square and the length of one side is 1, one of the first surfaces (squares) When the first electrode is provided so that the side of the first electrode is parallel to the longitudinal direction, the length of the first electrode in the longitudinal direction can be only 1 at maximum. On the other hand, when the first electrode is provided on the diagonal line of the first surface, the length of the first electrode in the longitudinal direction can be set to 1 or more. Therefore, if the same antenna length is required, the antenna can be made smaller if the longitudinal direction of the first electrode is not parallel to any side of the first surface.

Further, in the antenna according to the present invention, any one end of the first electrode located at both ends in the longitudinal direction, and any one end of the second electrode located at both ends in the longitudinal direction, The structure which overlaps may be sufficient.
For example, when the dielectric substrate has a structure in which the central portions of the first electrode and the second electrode intersect with each other when the dielectric substrate is seen in a plan view, the impedance can be adjusted by adjusting the position where both electrodes are fed in the region where both electrodes overlap. In addition to matching, it is possible to use a right-handed circularly polarized antenna or a left-handed circularly polarized antenna. On the other hand, if there is a relatively large conductive material (such as a human body or metal) near the antenna, the antenna that was originally intended for right-handed circular polarization is affected by this conductive material. There may be a problem that the antenna becomes a left-handed circularly polarized wave. On the other hand, when the dielectric substrate is viewed in plan, an antenna specialized for right-handed circular polarization or left-handed circular polarization has a structure in which ends of the first electrode and the second electrode intersect each other. Therefore, even if a conductive substance such as a human body is present near the antenna, the above-described problems do not occur.

  As is clear from the reciprocity theorem of the antenna, the antenna according to the present invention may be an antenna that receives circularly polarized waves or an antenna that transmits circularly polarized waves.

  The communication apparatus according to the present invention includes any one of the antennas described above. For example, a satellite mobile phone, a tablet terminal, a smartphone, a notebook computer, etc. can be exemplified as the communication device. The communication device also includes, for example, a circularly polarized wave communication module including an antenna, a feeder line, and a communication circuit (a transmission circuit or a reception circuit). The communication device may be a receiving device that receives circularly polarized waves or a transmitting device that transmits circularly polarized waves.

  An electronic apparatus according to the present invention includes any one of the antennas described above. For example, the electronic device includes a navigation device using GPS, a portable running device capable of calculating a position and speed by receiving radio waves from a GPS satellite, and measuring a moving distance, a moving speed, and the like, a GPS satellite A wristwatch or the like having a function of correcting the time by receiving a radio wave from is included. As in the case of the communication apparatus, the electronic device may be a device that receives circularly polarized waves or a device that transmits circularly polarized waves.

The antenna according to the present invention may have the following configuration.
A dielectric substrate having a first surface and a second surface facing each other, a strip-shaped first electrode provided along the first direction on the first surface, and the first direction on the second surface And when the dielectric substrate is viewed in plan, the first electrode and the second electrode intersect with each other, and the first electrode and the second electrode An antenna that feeds power to the first electrode and the second electrode in a region overlapping with the second electrode. In this case, the angle formed by the first direction and the second direction may be a right angle.

The antenna according to the present invention may have the following configuration.
A dielectric substrate having a first surface and a second surface facing each other, a strip-shaped first electrode provided on the first surface, and a strip-shaped second electrode provided on the second surface And when the dielectric substrate is viewed in plan, (1) the longitudinal direction of the first electrode is different from the longitudinal direction of the second electrode, and (2) the first electrode and the second electrode intersect each other. (3) An antenna that feeds power to the first electrode and the second electrode in a region where the first electrode and the second electrode overlap each other.

1 is a perspective view showing a structure of an antenna 1 according to a first embodiment. 3 is an enlarged perspective view showing feeding points 25 and 35 and a through hole 40. FIG. 2 is a partial cross-sectional view of the antenna 1 showing a structure of a portion of a through hole 40. FIG. 2 is a perspective view showing a structure of a coaxial cable 50. FIG. It is a top view of the antenna 1 when it sees from a Z-axis direction. It is a waveform diagram of a current I _B which is fed to the current I _A and the feeding point 35 is fed to the feeding point 25. FIG. 7 is a diagram showing directions of currents I _A and I _B fed to both electrodes 20 and 30 when the phase is 90 ° in the waveform diagram of FIG. 6. FIG. 7 is a diagram showing directions of currents I _A and I _B supplied to both electrodes 20 and 30 when the phase is 270 ° in the waveform diagram of FIG. 6. FIG. 7 is a diagram showing the direction of a current vector iα obtained by synthesizing currents I _A and I _B flowing in both electrodes 20 and 30 when the phase is 90 ° in the waveform diagram of FIG. 6. FIG. 7 is a diagram showing the direction of a current vector iα obtained by synthesizing currents I _A and I _B flowing in both electrodes 20 and 30 when the phase is 270 ° in the waveform diagram of FIG. 6. FIG. 3 is a development view showing dimensions of each part of the antenna 1. It is a figure which shows the directional characteristic of the antenna 1 in three dimensions. 3 is a graph showing the directivity characteristics of the antenna 1. It is a perspective view which shows the structure of the antenna 2 which concerns on 2nd Embodiment. It is a top view of the antenna 2 when it sees from a Z-axis direction. FIG. 3 is a development view showing dimensions of each part of the antenna 2. It is a figure which shows the directional characteristic of the antenna 2 in three dimensions. 5 is a graph showing the directivity characteristics of the antenna 2. 10 is a partial cross-sectional view of an antenna 1 ′ according to Modification 1. FIG. FIG. 10 is a plan view of an antenna 2 ′ according to Modification 3.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, the ratio of dimensions of each part is appropriately different from the actual one.
<A. First Embodiment>
FIG. 1 is a perspective view showing a structure of an antenna 1 according to the first embodiment. The X axis is an axis extending in a direction parallel to the upper surface 10A of the dielectric substrate 10. The Z axis is an axis extending in a direction perpendicular to the upper surface 10A. The Y axis is an axis extending in a direction perpendicular to the X axis and the Z axis.
The antenna 1 includes a dielectric substrate 10, an upper electrode 20 (first electrode), and a lower electrode 30 (second electrode). The dielectric substrate 10 has an upper surface 10A (first surface) and a lower surface 10B (second surface) facing each other. The upper electrode 20 has a rectangular shape and is formed on the upper surface 10A. The lower electrode 30 has a rectangular shape and is formed on the lower surface 10B.

  The dielectric substrate 10 has a rectangular parallelepiped outer shape, and is formed of a dielectric material such as plastic or ceramic, for example. The upper electrode 20 and the lower electrode 30 are formed of a conductor such as metal, and are formed on the surface of the dielectric substrate 10 by plating, screen printing, or the like, for example. Further, the length in the longitudinal direction (antenna length) of the upper electrode 20 and the lower electrode 30 is determined according to the frequency of the radio wave to be received or transmitted, the dielectric constant of the dielectric substrate 10, and the like. A feeding point 25 is provided on the upper electrode 20. The lower electrode 30 is provided with a feeding point 35. The feeding point 25 is a feeding position for the upper electrode 20, and the feeding point 35 is a feeding position for the lower electrode 30. The dielectric substrate 10 is provided with a through hole 40 (hole) that penetrates the dielectric substrate 10 in the Z-axis direction. The positions of both ends of the through hole 40 are a feeding point 25 and a feeding point 35.

FIG. 2 is an enlarged perspective view showing the feeding points 25 and 35 and the through hole 40. FIG. 3 is a partial cross-sectional view of the antenna 1 showing the structure of the through hole 40.
As shown in FIG. 2, the through hole 40 is a cylindrical through hole that penetrates the dielectric substrate 10 in the Z-axis direction. As shown in FIG. 3, the lower electrode 30 is provided with a circular opening OP (hole) so as to be concentric with the through hole 40. The diameter P of the opening OP is preferably larger than the diameter p of the through hole 40.

FIG. 4 is a perspective view showing the structure of the coaxial cable 50 (feed line).
The coaxial cable 50 includes, in order from the inside, an inner conductor (core wire) 52 formed of a conductor such as metal, an insulating layer 54 covering the periphery of the inner conductor 52, and an outer conductor (network) braided with a conductor such as metal. Line) 56 and an outer skin 58 covering the outer conductor 56. The material of the inner conductor 52 and the outer conductor 56 is, for example, copper. The insulating layer 54 and the outer skin 58 are made of an insulator such as polyethylene. The characteristic impedance of the coaxial cable 50 is, for example, 50Ω.

  Power is supplied to the upper electrode 20 and the lower electrode 30 from the lower surface 10B side of the dielectric substrate 10 using the coaxial cable 50. The inner conductor 52 of the coaxial cable 50 is inserted into the through hole 40 from the lower surface 10B side of the dielectric substrate 10 through the opening OP of the lower electrode 30, and the tip thereof is soldered to the upper electrode 20. Further, the outer conductor 56 of the coaxial cable 50 is soldered to the peripheral portion of the opening OP in the lower electrode 30. Thus, the feeding point 25 is a connection point between the inner conductor 52 of the coaxial cable 50 and the upper electrode 20. The feeding point 35 is a connection point between the outer conductor 56 of the coaxial cable 50 and the lower electrode 30, and is a part or all of the peripheral edge of the opening OP in the lower electrode 30.

FIG. 5 is a plan view of the antenna 1 when viewed from the Z-axis direction, that is, when viewed from a direction perpendicular to the upper surface 10A.
When the antenna 1 is viewed in plan from the Z-axis direction, the upper electrode 20 and the lower electrode 30 are orthogonal to each other and the end portions overlap each other. That is, the angle formed by the longitudinal direction of the upper electrode 20 and the longitudinal direction of the lower electrode 30 is 90 °. Further, the upper electrode 20 overlaps the lower left end in the drawing and the lower electrode 30 lower right in the drawing so as not to protrude from each other. When the region where the ends overlap each other is defined as an overlap region OLA, the feeding point 25 of the upper electrode 20 and the feeding point 35 of the lower electrode 30 are both located in the overlap region OLA. As a result of intensive studies by the inventor, impedance matching between the antenna 1, the coaxial cable 50, and the communication circuit (transmission circuit or reception circuit) is achieved by adjusting the positions of the feeding points 25 and 35 in the overlap region OLA. I understood that I could take it.

  In order to achieve impedance matching in this way, it is necessary to adjust the connection position of the coaxial cable 50 in the overlap region OLA. Accordingly, it is preferable that at least the width of the upper electrode 20 in the short direction or the width of the lower electrode 30 in the short direction is larger than the thickness of the coaxial cable 50. Moreover, impedance matching can be facilitated by setting the width in the short direction of the upper electrode 20 and the width in the short direction of the lower electrode 30 to be sufficiently larger than the thickness of the coaxial cable 50.

  Further, as shown in the figure, the two long sides of the upper electrode 20 are not parallel to any side of the upper surface 10A, and the two long sides of the lower electrode 30 are also parallel to any side of the lower surface 10B. If not, the antenna 1 can be miniaturized. This is because, in the same figure, the electrodes 20 and 30 are arranged on the dielectric substrate 10 while maintaining the orthogonal state so that the two long sides of the upper electrode 20 are parallel to the short sides of the upper surface 10A. If this is the case, it is clear from the fact that the length of the dielectric substrate 10 in the Y-axis direction must be increased.

  5 shows the case where the antenna 1 is viewed in plan from the Z-axis direction, but the upper electrode 20 and the lower electrode 30 are orthogonal to each other when the antenna 1 is viewed from the direction opposite to the Z-axis direction. However, there is no change in the point where the ends overlap.

Figure 6 is a waveform diagram of a current I _B which is fed to the current I _A and the feeding point 35 is fed to the feeding point 25. The vertical axis represents current amplitude, and the horizontal axis represents current phase.
As shown in the figure, the phase difference between the current I _A fed to the feeding point 25, the current I _B which is fed to the feeding point 35 is, for example, 180 °. That is, currents I _A and I _B having a phase difference of 180 ° are supplied to both electrodes 20 and 30 from the AC power source via the coaxial cable 50. The currents I _A and I _B are both high frequency currents. As described above, the inner conductor 52 of the coaxial cable 50 is connected to the upper electrode 20 through the through hole 40 from the lower surface 10B side of the dielectric substrate 10. Therefore, by adjusting the thickness of the Z-axis direction of the dielectric substrate 10, the current I _A fed to the feeding point 25 and _35, it is possible to produce a phase difference of 180 ° in I _B. The current I _A in this _way, when causing a phase difference in I _B, when the thickness of the Z-axis direction of the dielectric substrate 10, so that the phase of the amount corresponding to the current I _A is delayed.

FIG. 7 is a diagram showing the directions of currents I _A and I _B supplied to both electrodes 20 and 30 when the phase is 90 ° in the waveform diagram of FIG. FIG. 8 is a diagram showing the directions of currents I _A and I _B supplied to both electrodes 20 and 30 when the phase is 270 ° in the waveform diagram of FIG.
At the timing of phase 90 ° in the waveform diagram of FIG. 6, as shown by the arrows in FIG. 7, the direction of the current I _A flowing to the upper electrode 20, the direction toward the feed point 25 along the longitudinal direction of the upper electrode 20 becomes, the direction of the current I _B that flows through the lower electrode 30 is made in a direction towards the feed point 35 along the longitudinal direction of the lower electrode 30. Accordingly, a plan view of the antenna 1 from the Z-axis direction, the direction of orientation and the current I _B of the current I _A is a right angle. Further, the timing of the phase is 270 ° in the waveform diagram of FIG. 6, as shown by the arrows in FIG. 8, the direction of the current I _A flowing to the upper electrode 20 from the feeding point 25 along the longitudinal direction of the upper electrode 20 away becomes direction, the direction of the current I _B that flows through the lower electrode 30 is made in a direction away from the feed point 35 along the longitudinal direction of the lower electrode 30. Therefore, even if the 270 °, when viewed in plan the antenna 1 from the Z-axis direction, the direction of orientation and the current I _B of the current I _A is a right angle.

As described above, in the waveform diagram of FIG. 6, in the section of 0 ° or more and less than 180 °, the directions of the currents I _A and I _B flowing through the electrodes 20 and 30 are the directions toward the feeding points 25 and 35 as shown in FIG. become. Further, in the waveform diagram of FIG. 6, in the section of 180 ° or more and less than 360 °, the directions of the currents I _A and I _B flowing through the electrodes 20 and 30 are in a direction away from the feeding points 25 and 35 as shown in FIG. Become. The direction of orientation and the current I _B of the current I _A in any case at right angles. 7 and 8, the directions of the local currents I _A and I _B in the vicinity of the feeding points 25 and 35 may be different from the directions indicated by the arrows in the drawings. The directions of the currents I _A and I _B outside the vicinity are generally the directions indicated by the arrows in the figure.

  In addition, the current distribution is not uniform in the upper electrode 20 and the lower electrode 30, and a large current flows particularly in the two long sides (sides extending in the longitudinal direction). That is, a large current flows through both end portions of the upper electrode 20 and the lower electrode 30 extending in the longitudinal direction. Therefore, in order to obtain a larger wavelength shortening effect, each long side portion of the upper electrode 20 and the lower electrode 30 is surrounded by a dielectric, that is, each of the two long sides of the upper electrode 20 is formed on the upper surface 10A. It is important that each of the two long sides of the lower electrode 30 does not overlap any of the sides of the lower surface 10B.

  In the illustrated embodiment, three of the four corner vertices (both ends of each long side) of the upper electrode 20 overlap the edge of the upper surface 10A, and this is the same for the lower electrode 30. You may make it a vertex not overlap with the edge of upper surface 10A or lower surface 10B. In each of these apex portions (corner portions), the direction of current flow does not become the longitudinal direction of the electrode. Therefore, the portion of the upper electrode 20 except for both ends does not overlap with any side of the upper surface 10A, and the lower electrode 30 also includes the portion of the two long sides excluding both ends of the lower surface 10B. You may make it not overlap with the side. Thus, the apexes of the four corners in the upper electrode 20 and the lower electrode 30 may or may not overlap with the edges of the upper surface 10A and the lower surface 10B. Further, not only the two long sides but also the two short sides (sides extending in the short direction) of the upper electrode 20 and the lower electrode 30 do not overlap with the edges of the upper surface 10A and the lower surface 10B. Good.

Incidentally, the electric field generated by flowing a current I _A to the upper electrode 20 and E _A, when the electric field generated by flowing current I _B to the lower electrode 30 and E _B, of the electric field E _A and field E _B The waveform proceeds, for example, in the Z-axis direction or the opposite direction. Here, the thickness d in the Z-axis direction of the dielectric substrate 10 is generated from the upper electrode 20 and proceeds in the direction opposite to the Z-axis direction, and is radiated to the space on the lower surface 10B side of the dielectric substrate 10. the phase of the _a waveform with delaying 90 °, proceeds in the Z-axis direction generated from the lower electrode 30, the phase of the waveform of the electric field E _B that is radiated into space on the upper surface 10A side of the dielectric substrate 10 by 90 ° It is stipulated to delay. That is, the dielectric substrate 10, a phase difference of 90 ° in the waveform of the electric field E _A and the electric field E _B are combined in a space of the space and the lower surface 10B side of the upper surface 10A side occurs.

As described above, the thickness d of the dielectric substrate 10 in the Z-axis direction also plays a role of causing a phase difference of 180 ° between the currents I _A and I _B fed to the feeding points 25 and 35. Accordingly, the thickness d in the Z-axis direction of the dielectric substrate 10 causes a phase difference of 180 ° between the currents I _A and I _B fed to both the electrodes 20 and 30, and the space on the upper surface 10A side or the lower surface 10B. the waveform of the electric field E _a and the electric field E _B are combined in a space of the side is determined so as to generate a phase difference of 90 °.

As shown in FIG. 5, when the antenna 1 is viewed in a plan view from the Z-axis direction, the rectangular upper electrode 20 and the rectangular lower electrode 30 intersect (orthogonal). Thereby, the the direction of the current I _B that flows in the direction and the lower electrode 30 of the current I _A flowing to the upper electrode 20 has a quadrature component. Therefore, it is possible to make a state in which the electric field E _B generated from the electric field E _A and the lower electrode 30 which is generated from the upper electrode 20 intersecting at far field has a perpendicular component. The current _{I A} flowing to the upper electrode 20, a phase only 180 ° from the current _{I B} that flows through the lower electrode 30 is delayed. However, the dielectric substrate 10, in the space of the upper surface 10A side, the phase of the waveform of the electric field E _B generated from the lower electrode 30 is 90 ° delayed, in the space of the lower surface 10B side, the electric field E _A generated from the upper electrode 20 The phase of the waveform is delayed by 90 °. Therefore, finally, when the waveform of the electric field E _A and the electric field E _B are synthesized in the space of the space and the lower surface 10B side of the upper surface 10A side, so that both phases are shifted by 90 °.

As a result, the two electric fields E _A and E _B that intersect in the far field have orthogonal components, and a 90 ° phase difference can be generated in the waveforms of the two electric fields E _A and E _B. Therefore, the antenna 1 can receive and transmit circularly polarized waves in the same manner as when two orthogonal half-wavelength dipole antennas are fed with a phase difference of 90 °. Further, for example, when looking at the wave traveling direction the feeding point 25 as the viewpoint (for example, Z-axis direction or the opposite direction), the polarization plane obtained by the waveform of the electric field E _A and the electric field E _B with vector synthesis time Since it rotates clockwise (clockwise) with the passage of time, the antenna 1 becomes an antenna for right-handed circular polarization.

FIG. 9 is a diagram showing the direction of the current vector iα obtained by combining the currents I _A and I _B flowing through the electrodes 20 and 30 when the phase is 90 ° in the waveform diagram of FIG. FIG. 10 is a diagram showing the direction of the current vector iα obtained by combining the currents I _A and I _B flowing through the electrodes 20 and 30 when the phase is 270 ° in the waveform diagram of FIG.
In the antenna 1 according to the present embodiment, when the phase is 0 ° or more and less than 180 ° in the waveform diagram of FIG. 6, the direction of the current vector iα is the Y-axis direction as shown in FIG. In the waveform diagram of FIG. 6, when the phase is 180 ° or more and less than 360 °, the direction of the current vector iα is opposite to the Y axis as shown in FIG. 10. Thus, when the direction of the current vector iα is the Y axis, a directional characteristic (a right-handed circularly polarized wave component) having a donut shape with the Y axis as the central axis as shown in FIG. 12 is obtained.

FIG. 11 is a development view showing dimensions of each part of the antenna 1.
The dielectric substrate 10 has a rectangular parallelepiped outer shape of 29 mm (X-axis direction) × 17 mm (Y-axis direction) × 4 mm (Z-axis direction), for example. Both the upper electrode 20 and the lower electrode 30 have a rectangular outer shape of 20.5 mm × 3.5 mm. The lower electrode 30 is provided with a circular opening OP. The upper electrode 20 is formed at an inclination angle of 45 ° from the upper right to the lower center of the upper surface 10A. The lower electrode 30 is formed at an inclination angle of 45 ° from the upper center to the lower left of the lower surface 10B.

  In the drawing, “x” is the distance in the X-axis direction from the short side on the left side of the top surface 10A to the center of the feeding point 25, and this is the center of the feeding point 35 from the short side on the left side of the bottom surface 10B in the drawing. It is the same as the distance in the X-axis direction to (the center of the through hole 40 or the opening OP). In the figure, “y” is the distance in the Y-axis direction from the lower long side of the upper surface 10A in the drawing to the center of the feeding point 25, and this is the feeding point from the upper long side of the lower surface 10B in the drawing. It is the same as the distance in the Y-axis direction to the center of 35. For example, an example of the feeding position (x, y) where impedance matching can be achieved is shown. X is 13.6 mm and y is 3.2 mm.

The main material of the dielectric substrate 10 is, for example, BaO—TiO ₂ , and the dielectric substrate 10 has a relative dielectric constant of 110 and a dielectric loss tangent of 2 × 10 ⁻⁴ . The material of the upper electrode 20 and the lower electrode 30 is copper, and the thickness in the Z-axis direction of both the electrodes 20 and 30 is 10 μm. The diameter p of the through hole 40 is 0.15 mm.

Table 1 shows the characteristics of the antenna 1 composed of the above dimensions and materials.

  In Table 1, Cases 1 to 3 show characteristics when impedance matching is achieved by setting an appropriate power supply position (x, y), and Case 4 has an appropriate setting of the power supply position (x, y). The characteristic when impedance matching is not taken is shown. When impedance matching is achieved as in Cases 1 to 3, a sufficient return loss that is −30 dB or less at each resonance frequency can be obtained. On the other hand, when impedance matching is not achieved as in case 4, the return loss at the resonance frequency is about −5 dB.

  In any of cases 1 to 3, the normalized average gain of right-handed circular polarization is 0.97, whereas the normalized average gain of left-handed circular polarization is 0.03. It can be seen that 97% of these are right-handed circularly polarized waves. This is because the antenna 1 is an antenna that mainly emits a right-handed circularly polarized wave without radiating a left-handed circularly polarized wave, or a right-handed circularly-polarized wave with little reception of a left-handed circularly polarized wave. It shows that the antenna is actively receiving.

FIG. 12 is a diagram three-dimensionally showing the directivity characteristic (right-handed circularly polarized wave component) of the antenna 1. FIG. 13 is a graph showing the directivity characteristic (right-handed circularly polarized wave component) of the antenna 1.
The directivity characteristics shown in FIGS. 12 and 13 both relate to the antenna 1 described as case 1 in Table 1. As described above, in a circularly polarized patch antenna, right-handed circularly polarized wave is received and transmitted only in one of the space on the surface side where the radiation electrode is provided and the space on the surface side where the ground electrode is provided. I can't. On the other hand, in the antenna 1 according to the first embodiment, as is clear from FIGS. 12 and 13, not only the space on the upper surface 10A side where the upper electrode 20 is provided, but also the lower surface 10B side where the lower electrode 30 is provided. The right-handed circularly polarized wave can be received and transmitted at substantially the same level. In the XZ plane, right-handed circularly polarized waves can be received or transmitted in all directions.

As described above, according to this embodiment, the upper electrode 20 and the lower electrode 30 are arranged with the dielectric substrate 10 interposed therebetween. Here, when the dielectric substrate 10 is viewed in plan from the Z-axis direction, the rectangular upper electrode 20 and the rectangular lower electrode 30 intersect (orthogonal). Thereby, the the direction of the current I _B that flows in the direction and the lower electrode 30 of the current I _A flowing to the upper electrode 20 has a quadrature component. Therefore, it is possible to make a state in which the electric field E _B generated from the electric field E _A and the lower electrode 30 which is generated from the upper electrode 20 intersecting at far field has a perpendicular component. Further, by adjusting the thickness d of the Z-axis direction of the dielectric substrate 10, the phase difference between the current I _B which is fed to the current I _A and the lower electrode 30 fed to the upper electrode 20 to 180 ° together, radiated by the upper surface 10A side through the dielectric substrate 10 is generated from the waveform and the lower electrode 30 of the electric field E _a radiated to the lower surface 10B side through the dielectric substrate 10 is generated from the upper electrode 20 the phase of the waveform of the electric field E _B can be delayed by 90 °. Thus, the phase difference of 90 ° in the waveform of the electric field E _A and the electric field E _B are combined in a space of the space and the lower surface 10B side of the upper surface 10A side occurs.

As described above, in the antenna 1 according to this embodiment, the two electric fields E _A and E _B intersecting in the far field have orthogonal components, and the waveform of the two electric fields E _A and E _B has a phase difference of 90 °. Therefore, it is possible to receive and transmit circularly polarized waves. For example, when the traveling direction of the radio wave is viewed from the feeding point 25 as a viewpoint, the polarization plane obtained by vector synthesis of the waveforms of the two electric fields E _A and E _B rotates clockwise with the passage of time. Therefore, the antenna 1 according to this embodiment is a right-handed circularly polarized antenna.

  Moreover, according to this embodiment, since the dielectric substrate 10 is used, the antenna 1 can be reduced in size by the wavelength shortening effect. In particular, when the antenna 1 is viewed in plan from the Z-axis direction, the portion of the long sides of the electrodes 20 and 30 excluding both ends does not overlap with any side of the dielectric substrate 10. It is possible to make the size smaller. Further, the antenna 1 can be reduced in size by preventing the long sides of the electrodes 20 and 30 from being parallel to any of the sides of the dielectric substrate 10 when the antenna 1 is viewed in plan from the Z-axis direction. Can do.

  Further, the antenna 1 according to the present embodiment receives the right-handed circularly polarized wave at substantially the same level in both the space on the upper surface 10A side where the upper electrode 20 is provided and the space on the lower surface 10B side where the lower electrode 30 is provided. Or since it can transmit, its directivity is wide compared with a circularly polarized patch antenna. In other words, the right-handed circularly polarized wave can be received or transmitted by both the upper electrode 20 and the lower electrode 30.

  Furthermore, according to the present embodiment, impedance matching between the antenna 1, the coaxial cable 50, and the communication circuit (transmission circuit or reception circuit) is performed by adjusting the positions of the feeding points 25 and 35 in the overlap region OLA. Can be taken. Therefore, it is possible to achieve impedance matching on the antenna side without providing a matching circuit, and it is possible to increase the reception efficiency and transmission efficiency of the antenna 1 by eliminating reflection loss.

  Therefore, according to this embodiment, it is possible to provide a right-handed circularly polarized antenna 1 that is small in size, has a wide directivity, and can achieve impedance matching on the antenna side. In addition, since it is a small, circularly polarized antenna with wide directivity, it is particularly suitable for mounting on communication devices and electronic devices, such as mobile devices and wearable devices, where the orientation of the device itself varies depending on usage conditions. Yes. In addition, since the antenna 1 according to the present embodiment has 97% of the gain converted to the right-handed circularly polarized wave, the right-handed circularly polarized wave can be received or transmitted very efficiently.

<B. Second Embodiment>
Next, a second embodiment will be described. Note that description of parts common to the antenna 1 according to the first embodiment is omitted or simplified as appropriate.

FIG. 14 is a perspective view showing the structure of the antenna 2 according to the second embodiment.
The antenna 2 includes a dielectric substrate 60 having an upper surface 60A and a lower surface 60B facing each other, a strip-shaped upper electrode 70 provided on the upper surface 60A, and a strip-shaped lower electrode 80 provided on the lower surface 60B. The upper electrode 70 is provided with a feeding point 75, and the lower electrode 80 is provided with a feeding point 85. In addition, the dielectric substrate 60 is provided with a through hole 90 penetrating the dielectric substrate 60 in the Z-axis direction. The positions of both ends of the through hole 90 are a feeding point 75 and a feeding point 85.

  The antenna 2 according to this embodiment is different from the antenna 1 according to the first embodiment in that the outer shape of the dielectric substrate 60, the upper electrode 70 and the lower electrode 80 intersect in a cross shape, the feeding points 75 and 85, For example, the positions of the opening OP and the through hole 90. The cross-sectional structure of the antenna 2 where the through hole 90 is provided is the same as that shown in FIG. That is, the through hole 90 is a cylindrical through hole, and the lower electrode 80 is provided with a circular opening OP so as to be concentric with the through hole 90. Similarly to the case of the first embodiment, power is supplied to the upper electrode 70 and the lower electrode 80 from the lower surface 60B side of the dielectric substrate 60 using the coaxial cable 50 shown in FIG. Accordingly, the inner conductor 52 of the coaxial cable 50 is connected to the feeding point 75 of the upper electrode 70, and the outer conductor 56 of the coaxial cable 50 is connected to the feeding point 85 of the lower electrode 80.

FIG. 15 is a plan view of the antenna 2 when viewed from the Z-axis direction.
The upper surface 60A and the lower surface 60B are square, and the upper electrode 70 is formed on the upper surface 60A on a diagonal line connecting the upper right vertex and the lower left vertex in the drawing. Further, the lower electrode 80 is formed on the lower surface 60B on a diagonal line connecting the upper left vertex and the lower right vertex in the drawing. The upper electrode 70 and the lower electrode 80 are orthogonal to each other and the center portions overlap each other. When the region where the central portions overlap each other is defined as an overlap region OLA, the feed point 75 of the upper electrode 70 and the feed point 85 of the lower electrode 80 are both located in the overlap region OLA. As a result of intensive studies by the inventor, it has been found that impedance matching can be achieved by adjusting the positions of the feeding points 75 and 85 in the overlap region OLA.

  As shown in the figure, the two long sides of the upper electrode 70 are not parallel to any side of the upper surface 60A, and the two long sides of the lower electrode 80 are also parallel to any side of the lower surface 60B. If not, the antenna 2 can be reduced in size. For example, the case of the upper surface 60A and the upper electrode 70 will be described as an example. If the length of one side of the upper surface 60A (square) is assumed to be 1, the upper side of the upper surface 60A and the longer side are parallel to each other. When the electrode 70 is provided, the length of the long side of the upper electrode 70 can be only 1 at maximum. On the other hand, when the upper electrode 70 is provided on the diagonal line of the upper surface 60A, the length of the long side of the upper electrode 70 can be set to 1 or more. Therefore, if the same antenna length is required, the antenna 2 can be made smaller if the long side of the upper electrode 70 is not parallel to any side of the upper surface 60A.

Also in the antenna 2 according to this embodiment, the thickness d in the Z-axis direction of the dielectric substrate 60 is determined as in the first embodiment. Accordingly, the waveform of the current I _B which is fed to the upper electrode 70 waveform, and the lower electrode 80 of the current I _A fed to (feeding point 75) (feeding point 85), the same as FIG. 6, both the phase difference Becomes 180 °. Further, the electric field generated by flowing a current I _A to the upper electrode 70 and E _A, when the electric field generated by flowing current I _B to the lower electrode 80 and E _B, the upper surface 60A side space and the lower surface 60B the waveform of the electric field E _a and the electric field E _B are combined in a space on the side occurs a phase difference of 90 °.

When the antenna 2 is viewed in plan from the Z-axis direction, the rectangular upper electrode 70 and the rectangular lower electrode 80 intersect (orthogonal). Thus, because the direction of the current I _B that flows in the direction and the lower electrode 80 of the current I _A flowing to the upper electrode 70 will have a quadrature component, and the electric field E _A and the electric field E _B intersecting at the far field perpendicular A state with ingredients can be made. Therefore, the two electric fields E _A and E _B that intersect in the far field have orthogonal components, and a 90 ° phase difference can be generated in the waveforms of the two electric fields E _A and E _B. The antenna 2 according to the embodiment can also receive and transmit circularly polarized waves.

  As described above, when the antenna 2 according to the present embodiment is viewed in plan from the Z-axis direction, the electrodes 70 and 80 intersect in a cross shape, and the overlap region OLA is located at the center thereof. Therefore, the antenna 2 can be a right-hand circularly polarized antenna or a left-hand circularly polarized antenna depending on the positions of the feeding points 75 and 85. That is, the antenna 2 according to the present embodiment not only achieves impedance matching by adjusting the positions of the feed points 75 and 85 in the overlap region OLA, but can also be a right-handed circularly polarized antenna, It becomes possible to make an antenna for circular polarization. Further, depending on the positions of the feeding points 75 and 85, a linearly polarized antenna can be used.

FIG. 16 is a development view showing dimensions of each part of the antenna 2.
The dielectric substrate 60 has a rectangular parallelepiped outer shape of, for example, 17 mm (X-axis direction) × 17 mm (Y-axis direction) × 4 mm (Z-axis direction). Each of the upper electrode 70 and the lower electrode 80 has a rectangular outer shape of 20.5 mm × 3.5 mm. The upper electrode 70 is formed on the upper surface 60A on a diagonal line connecting the upper right apex and the lower left apex in the drawing with an inclination angle of 45 °. Further, the lower electrode 80 is formed on the diagonal line connecting the upper right vertex and the lower left vertex in the figure at the lower surface 60B at an inclination angle of 45 °.

  In the drawing, “x” is the distance in the X-axis direction from the left side of the upper surface 60A to the center of the feeding point 75, and this is the center of the feeding point 85 from the left side of the lower surface 60B in the drawing. It is the same as the distance in the X-axis direction to the center of the hole 90 and the opening OP. In the drawing, “y” is the distance in the Y-axis direction from the lower side of the upper surface 60A in the drawing to the center of the feeding point 75, and this is the distance from the upper side of the lower surface 60B to the feeding point 85 in the drawing. It is the same as the distance in the Y-axis direction to the center. For example, when an example is given with respect to a feeding position (x, y) for right-handed circular polarization capable of impedance matching, x is 8.2 mm and y is 8.5 mm.

Also, as in the first embodiment, the main material of the dielectric substrate 60 is a BaO-TiO ₂ for example, the relative dielectric constant of the dielectric substrate 60 is 110, the dielectric loss tangent is 2 × ^{10 -4} . The material of the upper electrode 70 and the lower electrode 80 is copper, and the thickness of the both electrodes 70 and 80 in the Z-axis direction is 10 μm. The through hole 90 has a diameter p of 0.15 mm.

Table 2 shows the characteristics of the antenna 2 composed of the above dimensions and materials.

  In Table 2, a feeding position (x, y) described as case 1 is a feeding position for right-handed circularly polarized waves that can achieve impedance matching. In case 1, a sufficient return loss is obtained that is -30 dB or less at the resonance frequency. In addition, the normalized average gain of right-handed circular polarization is 0.93, whereas the normalized average gain of left-handed circular polarization is 0.07, so 93% of the gain is converted to right-handed circular polarization. You can see that This is an antenna in which the antenna 2 mainly radiates right-handed circularly polarized light without substantially radiating left-handed circularly polarized light when the feeding position is set to x = 8.2 mm and y = 8.5 mm. This indicates that the antenna mainly receives the right-handed circularly polarized wave without receiving the left-handed circularly polarized wave.

  On the other hand, in Table 2, the feeding position (x, y) described as Case 2 is a feeding position for left-handed circularly polarized waves. In case 2, the return loss at the resonance frequency is −16.6 dB, which is not a sufficient value, but the normalized average gain of the left-handed circularly polarized wave is 0.97, whereas Since the normalized average gain of the circularly polarized wave is 0.03, it can be seen that 97% of the gain is the left circularly polarized wave. This is an antenna in which the antenna 2 mainly emits the left-handed circularly polarized wave without radiating the right-handed circularly polarized wave when the feeding position is set to x = 8.5 mm and y = 8.1 mm. This indicates that the antenna mainly receives the left-handed circularly polarized wave without receiving the right-handed circularly polarized wave.

FIG. 17 is a diagram three-dimensionally showing the directivity characteristic (right-handed circularly polarized wave component) of the antenna 2. FIG. 18 is a graph showing the directivity characteristics (right-handed circularly polarized wave component) of the antenna 2.
17 and 18 both relate to the right-handed circularly polarized antenna 2 described as case 1 in Table 2. As is clear from FIGS. 17 and 18, also in the antenna 2 according to the present embodiment, in both the space on the upper surface 60A side where the upper electrode 70 is provided and the space on the lower surface 60B side where the lower electrode 80 is provided, It is possible to receive and transmit right-handed circularly polarized waves at substantially the same level. In the XZ plane, right-handed circularly polarized waves can be received or transmitted in all directions.

  As described above, also in the antenna 2 according to this embodiment, the same effect as that of the antenna 1 according to the first embodiment can be obtained. In addition to this, the antenna 2 according to the present embodiment can be used not only for impedance matching by adjusting the positions of the feeding points 75 and 85 in the overlap region OLA but also for a right-handed circularly polarized antenna. It becomes possible to make an antenna for left-handed circular polarization. Further, since the size of the antenna in the XY plane can be suppressed to about 70% compared to the antenna 1 according to the first embodiment, further miniaturization can be achieved.

  Note that the antenna 2 according to the present embodiment has a structure in which the central portions of both the electrodes 70 and 80 are orthogonal to each other when viewed in plan from the Z-axis direction. It is possible to switch to a circularly polarized wave or a left-handed circularly polarized wave. However, as can be seen from a comparison of the power feeding positions (x, y) in case 1 and case 2 in Table 2, the difference between the power feeding positions is slight. Therefore, for example, if a relatively large conductive material (such as a human body or a metal) is present near the antenna 2, it should be originally intended for right-handed circular polarization under the influence of the conductive material. There may be a problem that the antenna 2 becomes the antenna 2 for left-handed circular polarization. On the other hand, the antenna 1 according to the first embodiment is specialized for right-handed circular polarization because the ends of the electrodes 20 and 30 are orthogonal to each other when viewed in plan from the Z-axis direction. Since the antenna can be used, even if a conductive substance such as a human body is present near the antenna 1, there is no problem of becoming a left-handed circularly polarized antenna.

<C. Application example>
Since the resonance frequency of the antenna illustrated in the first embodiment or the second embodiment is 1401 to 1497 MHz (except in case 4 in Table 1 where impedance matching is not achieved), a circularly polarized wave having a desired frequency is received. Or in order to transmit, it is necessary to adjust the dimension of the antenna. When the dimensions are adjusted, the dimensions of each part of the antenna may be multiplied by a constant according to the target frequency. For example, when the antenna 1 (resonance frequency: 1494 MHz) described as case 1 in Table 1 in the first embodiment is used as a GPS antenna that receives a GPS L1 signal, the transmission frequency of the L1 signal is 1575.42 MHz. Theoretically, the dimensions of each part of the antenna 1 may be multiplied by 1494 / 1575.42. Here, the thickness in the Z-axis direction of the upper electrode 20 and the lower electrode 30, the diameter p of the through hole 40, and the diameter P of the opening OP need not be multiplied by a constant. It should be noted that due to various factors, the actual value does not work as expected, and further dimensional adjustment is necessary with respect to the theoretical value.

  By performing the above dimension adjustment, for example, any one of the antennas exemplified in each embodiment is mounted as a GPS antenna on a mobile device or wearable device (for example, a notebook computer, a tablet terminal, a smartphone, a wristwatch, etc.). Can do. In addition, any of the antennas exemplified in each embodiment may be mounted on a car navigation device or a satellite mobile phone, and is not limited to satellite communication, for example, receives radio waves for radio tags (circular polarization). You may mount in a reading apparatus etc. As described above, the antenna according to the present invention can be mounted on various communication devices and electronic devices having a function of receiving or transmitting circularly polarized waves. The communication device includes a GPS communication module including any one of the antennas exemplified in each embodiment.

<D. Modification>
The present invention is not limited to the above-described embodiments, and for example, the following modifications are possible. Also, two or more of the following modifications can be combined as appropriate.

[Modification 1]
As shown in FIG. 19, a through-hole may not be provided, and a circular auxiliary electrode (third electrode) 100 formed of a conductor such as metal may be provided instead. This figure is a modification of the antenna 1 according to the first embodiment. The auxiliary electrode 100 is provided on the lower surface 10B of the dielectric substrate 10 ′ inside the opening OP of the lower electrode 30 so as to be concentric with the opening OP. For example, the material of the auxiliary electrode 100 is copper, and the thickness in the Z-axis direction is 10 μm. An internal conductor 52 of the coaxial cable 50 is connected to the auxiliary electrode 100. In consideration of soldering, the diameter S of the auxiliary electrode 100 is preferably larger than the diameter of the inner conductor 52 of the coaxial cable 50. Further, since the auxiliary electrode 100 is provided inside the opening OP, its diameter S is smaller than the diameter P of the opening OP.

Even with the above configuration, the upper electrode 20 (feeding point 25) is fed to the lower electrode 30 (feeding point 35) via the inner conductor 52 of the coaxial cable 50, the auxiliary electrode 100, and the dielectric substrate 10 ′. current _{I A} which only phase delayed 180 ° from the current _{I B} is is powered. In the case of the configuration shown in the figure, since it is not necessary to form a through hole in the dielectric substrate 10 ', the manufacturing process of the antenna 1' can be simplified correspondingly, and the manufacturing cost can be reduced. However, as described in the first embodiment, the provision of the through hole 40 can accurately determine the position of the feeding point 25 in the upper electrode 20, so that impedance matching can be easily achieved. Similar modifications can be applied to the second embodiment.

[Modification 2]
For example, in the first embodiment, power may be supplied from the upper surface 10 </ b> A side of the dielectric substrate 10. In this case, the opening OP is formed not in the lower electrode 30 but in the upper electrode 20. The outer conductor 56 of the coaxial cable 50 is connected to the feeding point 25 of the upper electrode 20, and the inner conductor 52 of the coaxial cable 50 is connected to the feeding point 35 of the lower electrode 30. The feeder line is not limited to the coaxial cable 50. Similar modifications can also be applied to the second embodiment.

[Modification 3]
For example, as shown in FIG. 20, the two long sides of the upper electrode 70 are parallel to the upper and lower sides of the upper surface 60A, and the two long sides of the lower electrode 80 are the left and right sides of the lower surface 60B. You may make it become parallel. Also, as shown in the figure, the two short sides of the upper electrode 70 overlap with the left and right sides of the upper surface 60A, and the two short sides of the lower electrode 80 overlap the upper and lower sides of the lower surface 60B. You may do it.

[Modification 4]
For example, in the antenna 1 according to the first embodiment, if the upper surface 10A provided with the upper electrode 20 and the lower surface 10B provided with the lower electrode 30 are switched, an antenna for left-handed circular polarization is obtained. However, it is necessary to readjust the positions of the feeding points 25 and 35 that can achieve impedance matching. Thus, the antenna 1 according to the first embodiment can be a left-handed circularly polarized antenna.

[Modification 5]
For example, in the first embodiment, when the antenna 1 is viewed in a plan view from the Z-axis direction, the upper electrode 20 and the lower electrode 30 do not need to be orthogonal to each other, and at least cross each other. Even if the angle at which the electrodes 20 and 30 intersect is, for example, 75 ° or 100 °, the reception performance and transmission performance are lower than in the case of 90 °, but it is used as an antenna for right-handed circular polarization. can do. However, as the angle at which the electrodes 20 and 30 intersect with each other moves away from 90 °, more unnecessary components such as linearly polarized waves are included, so that the reception performance and transmission performance of the antenna 1 deteriorate. Therefore, as described in the first embodiment, when the electrodes 20 and 30 are orthogonal, the ratio of the right-handed circularly polarized wave can be maximized in the total reception component or the total transmission component of the antenna 1. The reception performance and transmission performance of the antenna 1 can be improved. The same applies to the antenna 2 according to the second embodiment.

[Modification 6]
For example, in the first embodiment, by adjusting the thickness d of the dielectric substrate 10 in the Z-axis direction, a phase difference of 180 ° is generated in the currents I _A and I _B fed to both the electrodes 20 and 30. together, and to produce a phase difference of 90 ° in the waveform of the electric field E _a and the electric field E _B are combined in a space of the space and the lower surface 10B side of the upper surface 10A side. However, by adjusting the thickness d of the dielectric substrate 10 in the Z-axis direction, for example, a phase difference of 200 ° is generated in the currents I _A and I _B fed to both the electrodes 20 and 30, and the upper surface 10A may be causing a phase difference of 110 ° in the waveform of the electric field E _a and the electric field E _B are combined in a space of the space and the lower surface 10B side of the side. Further, the phase difference between the currents I _A and I _B may be set to 160 °, while a phase difference of 70 ° may be generated between the waveforms of the electric fields E _A and E _{B. A} phase shifter or the like may be used to adjust the phase difference between the currents I _A and I _B. The point is that the difference between the phase difference between the current and the phase difference between the electric fields should be 90 ° (the waveform of the two electric fields E _A and E _B intersecting in the far field is 90 °. A phase difference may be generated). The same applies to the antenna 2 according to the second embodiment.

[Modification 7]
The outer shape of the upper electrodes 20 and 70 and the lower electrodes 30 and 80 is not limited to a rectangle, and may be, for example, an elongated ellipse. Further, the upper electrodes 20 and 70 and the lower electrodes 30 and 80 may not have a constant width in the short-side direction or may not be linear. As described above, the outer shape of the upper electrodes 20 and 70 and the lower electrodes 30 and 80 may be a strip shape. Here, the band shape means a shape having a predetermined width and continuing long and narrow. Further, the outer shape of the dielectric substrates 10 and 60 is not limited to a rectangular parallelepiped, and may be, for example, a cylindrical shape. In addition, when the upper electrodes 20 and 70 and the lower electrodes 30 and 80 are polygons, the side portions constituting the polygon are edges, but the upper electrodes 20 and 70 and the lower electrodes 30 and 80 are not polygons. Is the edge of the outer periphery. The same applies to the dielectric substrates 10 and 60. Further, in the dielectric substrates 10 and 60, the upper surfaces 10A and 60A and the lower surfaces 10B and 60B may be opposed to each other, and are not necessarily parallel. Further, the upper surfaces 10A and 60A and the lower surfaces 10B and 60B do not have to be the same size.

[Modification 8]
In each of the above-described embodiments, for the sake of convenience, the Z-axis direction is the upper side and the opposite direction is the lower side. However, for example, the Y-axis direction may be the upper side and the opposite direction may be the lower side. Thus, the upper surface 10A, 60A and the lower surface 10B, 60B, or the upper electrode 20, 70 and the lower electrode 30, 80 do not define the absolute positional relationship between them.

1, 1 ', 2, 2' ... antenna 10, 10 ', 60 ... dielectric substrate, 10A, 60A ... upper surface (first surface), 10B, 60B ... lower surface (second surface), 20, 70 ... upper electrode (first electrode), 25, 75 ... upper electrode feeding point, 30, 80 ... lower electrode (second electrode), 35, 85 ... lower electrode feeding point, 40, 90 ... through hole (hole) 50 ... Coaxial cable (feed line), 52 ... Inner conductor, 54 ... Insulating layer, 56 ... Outer conductor, 58 ... Outer skin, 100 ... Auxiliary electrode, OP ... Opening (hole), OLA ... Overlapping region, I _A ... current supplied to the upper electrode, I _B ... current supplied to the lower electrode, d ... thickness in the Z-axis direction of the dielectric substrate, p ... diameter of the through hole, P ... diameter of the opening, S ... auxiliary Electrode diameter, iα ... current vector.

Claims (11)

A dielectric substrate having a first surface and a second surface facing each other;
A strip-shaped first electrode provided on the first surface;
A strip-shaped second electrode provided on the second surface;
When the dielectric substrate is viewed in plan view,
Supplying power to the first electrode and the second electrode in a region where the first electrode and the second electrode intersect and the first electrode and the second electrode overlap;
An antenna characterized by that. When the dielectric substrate is viewed in plan view,
The first electrode and the second electrode are orthogonal to each other;
The antenna according to claim 1. The width in the short direction of the first electrode or the width in the short direction of the second electrode is larger than the thickness of the feeder line;
The antenna according to claim 1 or 2. Either one of the first electrode and the second electrode and the dielectric substrate are formed with power feeding holes.
The antenna according to any one of claims 1 to 3. Of the edge extending in the longitudinal direction of the first electrode, the portion excluding both ends does not overlap the edge of the first surface, and the portion excluding both ends of the edge extending in the longitudinal direction of the second electrode is Does not overlap the edge of the second surface,
The antenna according to any one of claims 1 to 4, characterized in that: The edge extending in the longitudinal direction of the first electrode does not overlap with the edge of the first surface, and the edge extending in the longitudinal direction of the second electrode does not overlap with the edge of the second surface.
The antenna according to any one of claims 1 to 4, characterized in that: The edge of the first electrode does not overlap the edge of the first surface, and the edge of the second electrode does not overlap the edge of the second surface;
The antenna according to any one of claims 1 to 4, characterized in that: The longitudinal direction of the first electrode is not parallel to any side of the first surface, and the longitudinal direction of the second electrode is not parallel to any side of the second surface;
The antenna according to any one of claims 1 to 7, characterized in that When the dielectric substrate is viewed in plan view,
Any one end located at both ends in the longitudinal direction of the first electrode and any one end located at both ends in the longitudinal direction of the second electrode overlap.
The antenna according to any one of claims 1 to 8, wherein   A communication apparatus comprising the antenna according to claim 1. An electronic apparatus comprising the antenna according to claim 1.