JP2024008567A - patch antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a patch antenna that can easily realize desired operating characteristics.

SOLUTION: A patch antenna includes a ground pattern, a patch pattern placed opposite to the ground pattern, and a dielectric member placed between the ground pattern and the patch pattern, and the dielectric member is arranged so as to partially overlap the patch pattern when viewed from the direction from the patch pattern toward the ground pattern.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present disclosure relates to patch antennas.

One type of planar antenna is a patch antenna. Patch antennas can be designed integrally with circuits and are used, for example, in communication devices such as millimeter wave radars or global positioning satellite systems.

Antennas have operating characteristics such as resonant frequency, band, and polarization. The operating characteristics of a patch antenna are determined based on multiple parameters. For example, in a patch antenna, the shape of the patch pattern formed on the substrate by etching etc., the dielectric constant of the substrate, the thickness of the substrate (distance between the patch pattern and the ground pattern), the position of the feeding point, and the number of feeding points. The operating characteristics are determined based on a plurality of parameters such as:

Note that Patent Document 1 discloses a patch antenna that can easily adjust the impedance of a feeding point.

JP 2019-80277 Publication

As mentioned above, the operational characteristics of a patch antenna are determined based on multiple parameters. Therefore, in order to obtain desired operating characteristics in a patch antenna, for example, the plurality of parameters described above must be changed, which takes time and effort.

Non-limiting embodiments of the present disclosure contribute to providing a patch antenna that can easily achieve desired operating characteristics.

A patch antenna according to an embodiment of the present disclosure includes a ground pattern, a patch pattern placed opposite to the ground pattern, and a dielectric member placed between the ground pattern and the patch pattern, The dielectric member is arranged so as to overlap a part of the patch pattern when viewed from the direction from the patch pattern toward the ground pattern.

According to an embodiment of the present disclosure, desired operating characteristics can be easily achieved in a patch antenna.

1 is a side view of a patch antenna according to an embodiment; FIG. FIG. 3 is a view of the patch antenna seen from above. 2 is a side view of a patch antenna different from that shown in FIG. 1. FIG. 4 is a diagram illustrating an example of the operation of the patch antenna of FIG. 3. FIG. FIG. 3 is a diagram illustrating an example of the basic operation of a patch antenna. 6 is a diagram showing frequency characteristics of the patch antenna shown in FIG. 5. FIG. FIG. 3 is a diagram illustrating an example of setting a resonant frequency of a patch antenna. 8 is a diagram showing frequency characteristics of the patch antenna shown in FIG. 7. FIG. FIG. 3 is a diagram illustrating an example of a plurality of resonant frequencies of a patch antenna. 10 is a diagram showing frequency characteristics of the patch antenna shown in FIG. 9. FIG. FIG. 2 is a diagram illustrating an example of widening the resonant frequency of a patch antenna. 12 is a diagram showing frequency characteristics of the patch antenna shown in FIG. 11. FIG. FIG. 3 is a diagram illustrating an example of circularly polarized waves of a patch antenna. 14 is a diagram showing frequency characteristics of the patch antenna shown in FIG. 13. FIG. FIG. 3 is a diagram illustrating an example of circularly polarized waves of a patch antenna. 16 is a diagram showing frequency characteristics of the patch antenna shown in FIG. 15. FIG.

Embodiments of the present disclosure will be described in detail below with appropriate reference to the drawings.

FIG. 1 is a side view of a patch antenna 1 according to an embodiment. As shown in FIG. 1, the patch antenna 1 includes a substrate 11, a substrate 21, a spacer 31, and a dielectric member 41. Patch antenna 1 may be referred to as a microstrip patch antenna or a microstrip antenna.

In addition to the patch antenna 1, an RF (radio) circuit 51 is shown in FIG. Note that the patch antenna 1 may include the RF circuit 51. For example, the RF circuit 51 may be formed on the substrate 21.

A patch pattern 12 is formed on the substrate 11 . The patch pattern 12 is formed on the surface (upper surface) of the substrate 11 opposite to the surface facing the substrate 21 . The patch pattern 12 is formed, for example, over the entire upper surface of the substrate 11. Alternatively, the patch pattern 12 is formed on a portion of the upper surface of the substrate 11. Patch pattern 12 may be referred to as a patch conductor, a radiating pattern, or a planar radiating element.

The feeding point 13 is formed on the patch pattern 12 and connected to the RF circuit 51 . The feeding point 13 and the RF circuit 51 are connected, for example, through through holes formed in the substrates 11 and 21.

Substrate 21 is arranged to face substrate 11 . A ground pattern 22 is formed on the substrate 21 . The ground pattern 22 is formed on the surface (lower surface) of the substrate 21 opposite to the surface facing the substrate 11 . The ground pattern 22 is formed, for example, over the entire lower surface of the substrate 21. Alternatively, the ground pattern 22 is formed on a part of the lower surface of the substrate 21. The ground pattern 22 may be called a ground conductor.

The spacer 31 is sandwiched between the substrate 11 and the substrate 21 and fixes the substrate 11 and the substrate 21. The substrate 11 and the substrate 21 are fixed to the spacer 31 so as to face each other and be parallel to each other. The spacer 31 may be, for example, a screw or double-sided tape. In consideration of dielectric loss and the like, it is preferable to use a material with a low dielectric constant as the spacer 31, for example.

Dielectric member 41 is inserted between substrate 11 and substrate 21 . The dielectric member 41 has, for example, a rectangular parallelepiped shape. The thickness of the dielectric member 41 is, for example, the distance between the substrate 11 and the substrate 21 or smaller than that distance. The dielectric member 41 can be freely arranged in a space between the substrate 11 and the substrate 21 without the spacer 31.

The dielectric member 41 is a member with a high dielectric constant. The dielectric member 41 is made of rubber such as nitrile rubber, for example.

As will be described later, the operating characteristics of the patch antenna 1, such as the resonant frequency, band, and polarization, vary depending on the position of the dielectric member 41. For example, after the desired operating characteristics (designed operating characteristics) of the patch antenna 1 are obtained, the dielectric member 41 is fixed to both or one of the substrate 11 and the substrate 21 at a position where the desired operating characteristics are obtained. Ru.

FIG. 2 is a diagram of the patch antenna 1 viewed from above. In FIG. 2, the same components as in FIG. 1 are given the same reference numerals.

A dashed line A2b shown in FIG. 2 indicates a spacer 31 disposed between the substrate 11 and the substrate 21. A dotted line A2c shown in FIG. 2 indicates the dielectric member 41 disposed between the substrate 11 and the substrate 21.

The substrate 11 has, for example, a rectangular shape. As described above, the patch pattern 12 is formed over the entire upper surface of the substrate 11, or is formed in a planar shape on a part of the upper surface of the substrate 11. In the following, it is assumed that the patch pattern 12 is formed over the entire upper surface of the substrate 11.

The substrate 21 has, for example, a rectangular shape. As described above, the ground pattern 22 (not shown in FIG. 2) is formed over the entire lower surface of the substrate 21, or is formed in a planar shape on a part of the lower surface of the substrate 21. In the following, it is assumed that the ground pattern 22 is formed over the entire lower surface of the substrate 21.

The patch pattern 12 is arranged so as to overlap the ground pattern 22. For example, the patch pattern 12 is arranged so that the entire patch pattern 12 is within the outer periphery of the ground pattern 22.

The spacer 31 has, for example, a rectangular shape as shown by a dashed line A2b. The spacer 31 has an area smaller than the area of the patch pattern 12 and is arranged so as to overlap the patch pattern 12. For example, the spacer 31 is arranged so that the entire spacer 31 is within the outer periphery of the patch pattern 12.

Thereby, the patch antenna 1 has a space between the patch pattern 12 and the ground pattern 22 in which the dielectric member 41 (dotted line A2c in FIG. 2) is arranged. In other words, the dielectric member 41 can be arranged between the substrates 11 and 21 so as to overlap the patch pattern 12 and the ground pattern 22.

In the example of FIG. 1, the dielectric member 41 is arranged in a space formed between the patch pattern 12 and the ground pattern 22 along one side of the patch pattern 12 that is farthest from the feeding point 13.

Note that the shapes of the substrates 11 and 21, the patch pattern 12, the ground pattern 22, the spacer 31, and the dielectric member 41 are not limited to the rectangular shape. These shapes may be circular, for example.

FIG. 3 is a side view of patch antenna 60, which is different from FIG. As shown in FIG. 3, the patch antenna 60 includes a substrate 61 and an RF circuit 65.

A patch pattern 62 is formed on the upper surface of the substrate 61. A ground pattern 64 is formed on the lower surface of the substrate 61.

A power feeding point 63 is formed in the patch pattern 62 . The feeding point 63 is connected to an RF circuit 65 .

FIG. 4 is a diagram illustrating an example of the operation of patch antenna 60 in FIG. 3. FIG. 4A shows the patch pattern 62 viewed from above. FIG. 4B shows the patch antenna 60 seen from the side. In FIG. 4, the same components as in FIG. 3 are given the same reference numerals.

When a signal is supplied from the RF circuit 65 to the power feeding point 63, a current flows in the length direction of the patch pattern 62 (in the left-right direction in FIG. 4), as shown by the dotted arrow A4a in FIG. The current increases near the center of the patch pattern 62 and decreases toward both ends of the patch pattern 62 in the length direction. On the other hand, the voltage decreases near the center of the patch pattern 62 and increases toward both ends of the patch pattern 62 in the length direction. As a result, as shown by arrow A4b in FIG. 4, an electric field is generated around the end of the patch pattern 62, and radio waves are emitted.

Patch antenna 60 has operating characteristics such as resonant frequency, band, and polarization. In order to obtain desired operating characteristics in the patch antenna 60, for example, the shape of the patch pattern 62, the dielectric constant of the substrate 61, the thickness of the substrate 61 (distance between the patch pattern 62 and the ground pattern 64), and the distance of the feeding point 63 are required. Parameters such as the position and the number of feeding points 63 are changed.

In the patch antenna 60 in which the patch pattern 62 and the ground pattern 64 are formed on the front and back sides of the substrate 61, the above-mentioned parameters have to be changed in order to obtain a desired resonance frequency, which takes time and effort.

On the other hand, in the patch antenna 1 shown in FIGS. 1 and 2, the operating characteristics are changed depending on the position of the dielectric member 41, as described below. Thereby, the patch antenna 1 can easily achieve desired operating characteristics.

A method for realizing the operational characteristics of the patch antenna 1 will be described below.

<Basic operation example>
FIG. 5 is a diagram illustrating an example of the basic operation of the patch antenna 1. FIG. 5A shows the patch antenna 1 seen from the side. FIG. 5B shows the patch pattern 12 viewed from above. In FIG. 5, the same components as in FIGS. 1 and 2 are given the same reference numerals. Note that, in FIG. 5, illustration of some of the constituent elements shown in FIGS. 1 and 2 is omitted.

In the patch antenna 1 shown in FIG. 5, the dielectric member 41 is not arranged. An arrow A5a shown in FIG. 5(B) indicates a current flowing through the patch pattern 12.

FIG. 6 is a diagram showing the frequency characteristics of the patch antenna 1 shown in FIG. 5. FIG. 6A shows the frequency characteristics of current amplitude. FIG. 6B shows the frequency characteristics of the current phase.

As shown in FIG. 6A, the resonant frequency of the patch antenna 1 without the dielectric member 41 is f0.

As shown in FIG. 6B, the phase at the resonant frequency f0 of the patch antenna 1 is 0. As shown in FIG. 6B, at frequencies lower than the resonant frequency f0, the phase of the current flowing through the patch antenna 1 advances relative to the phase of the current of the signal source (RF circuit 65), and has a C characteristic. At frequencies higher than the resonance frequency f0, the phase is delayed and has an L characteristic.

<Example of resonant frequency setting>
FIG. 7 is a diagram illustrating an example of setting the resonant frequency of the patch antenna 1. FIG. 7A shows the patch antenna 1 seen from the side. FIG. 7B shows the patch pattern 12 viewed from above. In FIG. 7, the same components as in FIG. 5 are given the same reference numerals.

In the patch antenna 1 shown in FIG. 7, a dielectric member 41 is arranged between the patch pattern 12 and the ground pattern 22. For example, the dielectric member 41 is placed at a position indicated by the dotted line A7b in FIG. 7(B). Specifically, the dielectric member 41 is located on the side farther from the power feeding point 13 of the two sides in the length direction (left and right direction in FIG. 7) of the patch pattern 12, and is connected to the patch pattern 12 and the ground pattern. 22. The dielectric member 41 is arranged across the width direction of the patch pattern 12 (vertical direction in FIG. 7).

FIG. 8 is a diagram showing the frequency characteristics of the patch antenna 1 shown in FIG. 7. FIG. 8A shows the frequency characteristics of current amplitude. FIG. 8B shows the frequency characteristics of the current phase. FIG. 8 also shows the resonance frequency f0 when the dielectric member 41 is not provided (basic operation).

As shown in FIG. 7, when the dielectric member 41 is placed between the patch pattern 12 and the ground pattern 22, the resonant frequency of the patch antenna 1 is lowered. For example, as shown at f0' in FIG. 8A, the resonant frequency of the patch antenna 1 is lower than the resonant frequency f0 when there is no dielectric member 41 (basic operation).

By disposing the dielectric member 41 between the patch pattern 12 and the ground pattern 22, the wavelength of the current shown by arrow A7a in FIG. 7(B) is compressed more than when the dielectric member 41 is not disposed. It takes. This lowers the resonant frequency of the patch antenna 1.

The resonant frequency of the patch antenna 1 can be set to various values by changing the position of the dielectric member 41. For example, in order to further lower the resonant frequency of the patch antenna 1, the dielectric member 41 shown in FIG. 7 is moved toward the open end side of the patch pattern 12 where the electric field becomes stronger. By moving the dielectric member 41 toward the open end side of the patch pattern 12, the wavelength of the current shown by arrow A7a becomes longer and the resonant frequency of the patch antenna 1 becomes lower.

Further, the resonant frequency of the patch antenna 1 can be set to various values by, for example, changing the width of the dielectric member 41 (the length in the left-right direction in FIG. 7A). For example, in order to further lower the resonant frequency of the patch antenna 1, the width of the dielectric member 41 shown in FIG. 7 is increased. By increasing the width of the dielectric member 41, the area of the dielectric member 41 that acts on the electric field increases, the wavelength of the current shown by arrow A7a becomes longer, and the resonant frequency of the patch antenna 1 decreases. In particular, by increasing (extending) the width of the dielectric member 41 on the open end side of the patch pattern 12 where the electric field is strong, the resonant frequency of the patch antenna 1 is greatly reduced.

In this way, by changing the position or width (size) of the dielectric member 41, the resonant frequency of the patch antenna 1 can be easily set.

Note that the dielectric member 41 may be arranged between the patch pattern 12 and the ground pattern 22 along at least one of the four sides of the patch pattern 12 (parallel to one side).

Note that the electric field and voltage are large on the sides of the patch pattern 12 that are orthogonal to the current. Therefore, when the patch pattern 12 is arranged along the side perpendicular to the current, the resonant frequency of the patch antenna 1 can be changed significantly. That is, if the patch pattern 12 is arranged along the side perpendicular to the current, rough adjustment can be made. Furthermore, the electric field and voltage are small on the sides of the patch pattern 12 that are parallel to the current. Therefore, when the patch pattern 12 is arranged along the side parallel to the current, the resonant frequency of the patch antenna 1 can be changed to a small value. That is, when the patch pattern 12 is arranged along the side parallel to the current, fine adjustment can be made.

<Multiple resonant frequencies>
The patch antenna 1 has a plurality of resonant frequencies depending on the position of the dielectric member 41. For example, the patch antenna 1 has two resonant frequencies depending on the position of the dielectric member 41.

FIG. 9 is a diagram illustrating an example of multiple resonance frequencies of the patch antenna 1. FIG. 9A shows the patch antenna 1 seen from the side. FIG. 9B shows the patch pattern 12 viewed from above. In FIG. 9, the same components as in FIG. 5 are given the same reference numerals.

In the patch antenna 1 shown in FIG. 9, a dielectric member 41 is arranged. For example, the dielectric member 41 is placed at the position shown in FIG. 9(B). Specifically, the dielectric member 41 is disposed on one of the two diagonals of the patch pattern 12, and between the patch pattern 12 and the ground pattern 22 at the end of the diagonal. In other words, the dielectric member 41 is arranged between the patch pattern 12 and the ground pattern 22 at the corner of the patch pattern 12 .

FIG. 10 is a diagram showing the frequency characteristics of the patch antenna 1 shown in FIG. 9. FIG. 10A shows the frequency characteristics of current amplitude. FIG. 10(B) shows the frequency characteristics of the current phase.

As shown in FIG. 9, when the dielectric member 41 is placed diagonally between the patch pattern 12 and the ground pattern 22, the electric field of the patch pattern 12 is distorted, and the current flowing through the patch pattern 12 is shunted. be done. For example, the current flowing through the patch pattern 12 is divided into two in the diagonal direction of the patch pattern 12, as shown by arrows A9a and A9b in FIG. 9(B). Therefore, the patch antenna 1 shown in FIG. 9 has two resonance frequencies f1 and f2, as shown in FIG. 10(A). Furthermore, as shown in FIG. 10(B), the patch antenna 1 has a phase of 0 at the resonance frequencies f1 and f2.

The wavelength of the current shown by arrow A9a in FIG. 9(B) is compressed by the dielectric member 41 more than the wavelength of the current shown by arrow A9b. As a result, the resonant frequency f1 of the current indicated by arrow A9a becomes lower than the resonant frequency f2 of the current indicated by arrow A9b.

The interval between the two resonant frequencies f1 and f2 of the patch antenna 1 can be changed by changing the position of the dielectric member 41. For example, in order to separate the two resonance frequencies f1 and f2 of the patch antenna 1 further, the dielectric member 41 shown in FIG. 9 is moved toward the open end side (diagonal end) of the patch pattern 12 where the electric field becomes stronger. let By moving the dielectric member 41 toward the open end side of the patch pattern 12, the resonance frequency f1 is further lowered. As the resonant frequency f1 decreases, the frequency of phase 0 corresponding to the resonant frequency f1 also decreases.

Further, the two resonance frequencies f1 and f2 of the patch antenna 1 can be changed, for example, by changing the width of the dielectric member 41 (the length in the diagonal direction of the patch pattern 12). For example, in order to separate the two resonance frequencies f1 and f2 further, the width of the dielectric member 41 shown in FIG. 9B in the diagonal direction of the patch pattern 12 is increased. By increasing the width of the dielectric member 41, the area of the dielectric member 41 that acts on the electric field becomes larger, the wavelength of the current shown by the arrow A9a becomes longer, and the resonant frequency f1 decreases. In particular, by increasing (stretching) the width of the dielectric member 41 on the open end side of the patch pattern 12 where the electric field is strong, the patch resonance frequency f1 is significantly reduced.

Note that in FIG. 9, the dielectric member 41 is arranged on one of the two diagonals, but the dielectric member 41 may be arranged on both of the two diagonals. In this case, each of the two resonance frequencies f1 and f2 can be changed. Further, the dielectric members 41 may be arranged at the four corners of the patch pattern 12.

In this way, by arranging the dielectric member 41 on the diagonal of the patch pattern 12, the resonant frequencies of the patch antenna 1 can be made plural. Further, by changing the position or size of the dielectric member 41, the plurality of resonant frequencies can be easily changed.

<Broadband>
As described with reference to FIGS. 9 and 10, the patch antenna 1 has a plurality of resonant frequencies depending on the position of the dielectric member 41. Furthermore, the plurality of resonance frequencies are changed depending on the position of the dielectric member 41. Therefore, the patch antenna 1 has a wide band by bringing the plurality of resonant frequencies close to each other depending on the position of the dielectric member 41.

FIG. 11 is a diagram illustrating an example of widening the resonance frequency of the patch antenna 1. In FIG. 11, the same components as in FIG. 9 are given the same reference numerals.

In the patch antenna 1 shown in FIG. 11, the dielectric members 41 are arranged diagonally as in FIG. 9. However, in the patch antenna 1 shown in FIG. 11, the dielectric member 41 is arranged so that the dielectric member 41 overlaps with the patch pattern 12 less than the patch antenna 1 shown in FIG.

FIG. 12 is a diagram showing the frequency characteristics of the patch antenna 1 shown in FIG. 11. FIG. 12A shows the frequency characteristics of current amplitude. FIG. 12B shows the frequency characteristics of the current phase.

Patch antenna 1 shown in FIG. 11 has two resonant frequencies. However, as shown in FIG. 12(A), the two resonant frequencies of the patch antenna 1 shown in FIG. It is smaller than the distance between the resonance frequencies f1 and f2.

As described above, the patch antenna 1 shown in FIG. 11 is arranged so that the dielectric member 41 overlaps with the patch pattern 12 less than the patch antenna 1 shown in FIG. Therefore, the area of the dielectric member 41 that acts on the electric field becomes smaller, and the distance between the two resonance frequencies becomes smaller.

Note that as the dielectric member 41 is moved closer to the center of the patch pattern 12 where the electric field becomes smaller, for example, the solid line waveform shown in FIG. Similarly, the phase waveform shown in FIG. 12(B) also becomes one waveform.

In this way, by adjusting the position or size of the dielectric member 41 arranged on the diagonal of the patch pattern 12, the resonant frequency of the patch antenna 1 can be widened.

<Circular polarization (left rotation)>
As described with reference to FIGS. 9 and 10, the patch antenna 1 has a plurality of resonant frequencies depending on the position of the dielectric member 41. In addition, the plurality of resonance frequencies are changed depending on the position of the dielectric member 41, and the phase thereof is also changed. Therefore, the patch antenna 1 can set circularly polarized waves by adjusting the phase of the plurality of resonant frequencies depending on the position of the dielectric member 41.

FIG. 13 is a diagram illustrating an example of circularly polarized waves of the patch antenna 1. In FIG. 13, the same components as in FIG. 9 are given the same reference numerals. A dotted line A13a shown in FIG. 13(B) indicates a dielectric member 41 disposed between the patch pattern 12 and the ground pattern 22.

In the patch antenna 1 shown in FIG. 13, the dielectric members 41 are arranged diagonally as in FIG. 9. However, in the patch antenna 1 shown in FIG. 13, the dielectric member 41 is different from the patch antenna 1 shown in FIG. Placed.

The dielectric member 41 is disposed on a diagonal line having a left end, which is two of the four ends of the two diagonal lines of the patch pattern 12, which are farthest from the feeding point 13. For example, in (B) of FIG. 13, among the four ends of two dashed double-dotted lines A13b and A13c indicating two diagonals, two ends far away from the feed point 13 (the ends indicated by arrows A13d and A13e) ), the dielectric member 41 is arranged on a diagonal line (on the two-dot chain line A13b) having the left end (the end indicated by the arrow A13d). In other words, of the two ends (ends indicated by arrows A13d and A13e) of the patch pattern 12 furthest from the feed point 13, at the left end (corner) when viewed from the feed point 13, the dielectric member 41 is placed. As a result, the circularly polarized wave rotates to the left.

In addition, the dielectric member 41 is located at the two ends near the two diagonal lines of the patch pattern 12 when viewed from the power feeding point 13, and at the right end (indicated by the arrow A13d on the two-dot chain line A13b). Circularly polarized waves are also right-handed when placed diagonally with the ends opposite to those shown).

FIG. 14 is a diagram showing the frequency characteristics of patch antenna 1 shown in FIG. 13. FIG. 14A shows the frequency characteristics of current amplitude. FIG. 14B shows the frequency characteristics of the current phase.

Patch antenna 1 shown in FIG. 13 has two resonant frequencies similarly to the frequency characteristics shown in FIG. 10. However, in the patch antenna 1 shown in FIG. 13, the phase difference between the two phases at the frequency of the intersection of the two amplitude frequency characteristics is 90 degrees. For example, as shown in FIG. 14(A), the frequency at the intersection of two amplitude-frequency characteristics is f0. The dielectric member 41 is arranged on one of the two diagonals of the patch pattern 12 so that the phase difference between the two at the frequency f0 is 90 degrees as shown in FIG. 14(B).

In this way, left-handed circular polarization can be set by adjusting the position of the dielectric member 41 arranged on the diagonal of the patch pattern 12.

Note that the frequency f0 (frequency of circularly polarized wave) shown in FIG. 14 can be changed. For example, the dielectric member 41 is also arranged at the end (corner) indicated by the arrow A13e in FIG. 13(B). By changing the positions of the dielectric members 41 placed at the two corners, left-handed circularly polarized waves are realized. Then, while maintaining the left-handed circularly polarized wave, the positions of the dielectric members 41 placed at the two corners are changed to change the frequency f0.

<Circular polarization (right rotation)>
A case where circularly polarized waves are rotated to the right will be explained.

FIG. 15 is a diagram illustrating an example of circularly polarized waves of the patch antenna 1. In FIG. 15, the same components as in FIG. 13 are given the same reference numerals. A dotted line A15a shown in FIG. 15(B) indicates the dielectric member 41 disposed between the patch pattern 12 and the ground pattern 22.

In the patch antenna 1 shown in FIG. 15, the dielectric members 41 are arranged diagonally as in FIG. 13. However, the patch antenna 1 shown in FIG. 15 differs from the patch antenna 1 shown in FIG. 13 in the position where the dielectric member 41 is arranged.

The dielectric member 41 is arranged on a diagonal line having two ends on the right side, which are the two ends farthest from the feed point 13, among the four ends of the two diagonals of the patch pattern 12. For example, in (B) of FIG. 15, among the four ends of two dashed double-dotted lines A15b and A15c indicating two diagonals, two ends far away from the feed point 13 (ends indicated by arrows A15d and A15e) ), the dielectric member 41 is disposed on a diagonal line (on the two-dot chain line A15c) having the right end (the end indicated by the arrow A15e). In other words, of the two ends of the side of the patch pattern 12 furthest from the feed point 13 (the ends indicated by arrows A15d and A15e), the dielectric member is 41 is placed. As a result, the circularly polarized wave rotates to the right.

In addition, the dielectric member 41 is located at two ends near the two diagonal lines of the patch pattern 12 when viewed from the feed point 13, and at the left end (indicated by the arrow A15e on the two-dot chain line A15c). Circularly polarized waves are also right-handed when placed diagonally with the ends opposite to those shown).

FIG. 16 is a diagram showing the frequency characteristics of patch antenna 1 shown in FIG. 15. FIG. 16A shows the frequency characteristics of current amplitude. FIG. 16(B) shows the frequency characteristics of the current phase.

Patch antenna 1 shown in FIG. 15 has two resonant frequencies similarly to the frequency characteristics shown in FIG. 10. However, in the patch antenna 1 shown in FIG. 15, the phase difference between the two phases at the frequency of the intersection of the two amplitude frequency characteristics is 90 degrees. For example, as shown in FIG. 16(A), the frequency at the intersection of two amplitude frequency characteristics is f0. The dielectric member 41 is arranged on one of the two diagonals of the patch pattern 12 so that the phase difference between the two at the frequency f0 is 90 degrees as shown in FIG. 16(B).

In this way, left-handed circular polarization can be set by adjusting the position of the dielectric member 41 arranged on the diagonal of the patch pattern 12.

Note that the frequency f0 (frequency of circularly polarized wave) shown in FIG. 16 can be changed. For example, the dielectric member 41 is also arranged at the end (corner) indicated by the arrow A15d in FIG. 15(B). By changing the positions of the dielectric members 41 placed at the two corners, right-handed circularly polarized waves are realized. Then, while maintaining the right-handed circularly polarized wave, the positions of the dielectric members 41 placed at the two corners are changed, and the frequency f0 is changed.

<Summary of embodiments>
As explained above, the patch antenna 1 includes the ground pattern 22, the patch pattern 12 arranged opposite to the ground pattern 22, the dielectric member 41 arranged between the ground pattern 22 and the patch pattern 12, Equipped with. The dielectric member 41 is arranged so as to overlap a part of the patch pattern 12 when viewed from the direction from the patch pattern 12 toward the ground pattern 22.

Thereby, the patch antenna 1 can easily achieve desired operating characteristics. For example, by changing the position of the dielectric member 41 placed between the ground pattern 22 and the patch pattern 12, desired operating characteristics can be easily achieved.

Furthermore, the patch antenna 1 can achieve various operating characteristics depending on the position of the dielectric member 41. Therefore, for example, it is only necessary to determine the position of the dielectric member 41 for various required operating characteristics, and the position of the other members (substrate 11, patch pattern 12, feed point 13, substrate 21, ground pattern 22, spacer 31, , dielectric member 41) need not be designed for each required operating characteristic.

Furthermore, the dielectric member 41 is arranged between the ground pattern 22 and the patch pattern 12 so as to overlap a part of the patch pattern 12 . Therefore, the patch antenna 1 can suppress dielectric loss caused by the dielectric member 41.

<Modification 1>
In the above description, the patch pattern 12 is formed on the substrate 11 and the ground pattern 22 is formed on the substrate 21, but the present invention is not limited to this. For example, the patch pattern 12 may be formed of a single metal plate, and may not be formed on the substrate 11. For example, the ground pattern 22 may be formed of a single metal plate, and may not be formed on the substrate 21.

<Modification 2>
In the above description, the dielectric member 41 is arranged between the patch pattern 12 and the ground pattern 22, but the present invention is not limited thereto. The dielectric member 41 may be arranged around the patch pattern 12 instead of between the patch pattern 12 and the ground pattern 22. Even around the patch pattern 12, there are places where the electric field extends, and when the dielectric member 41 is placed in such a place, the operating characteristics of the patch antenna 1 can be changed.

The patch antenna of the present disclosure can be used, for example, in a communication device such as a millimeter wave radar or a global positioning satellite system.

1 Patch antenna 11, 21 Substrate 12 Patch pattern 13 Feeding point 22 Ground pattern 31 Spacer 41 Dielectric member

Claims (5)

ground pattern and
a patch pattern arranged opposite to the ground pattern;
a dielectric member disposed between the ground pattern and the patch pattern;
Equipped with
The dielectric member is arranged so as to overlap a part of the patch pattern when viewed from the direction from the patch pattern toward the ground pattern.
patch antenna. the dielectric member is arranged along at least one side of the rectangular patch pattern;
The patch antenna according to claim 1. the dielectric member is disposed at at least one corner of the rectangular patch pattern;
The patch antenna according to claim 1. The band of the patch antenna, left-handed polarization, or right-handed polarization is set depending on the position of the dielectric member placed at the corner.
The patch antenna according to claim 3. the dielectric member is rubber;
The patch antenna according to claim 1.

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