Patch antenna and antenna module

Abstract

Provided is a patch antenna and an antenna module, whereby isolation between ports if two polarized waves are transmitted and received can be increased, and the occurrence of crosstalk between two signals can be suppressed. The patch antenna comprises: a dielectric layer having a first main surface and a second main surface; a patch disposed on the first main surface; a ground disposed on the second main surface; three or more connection vias connected to the patch; a first via electrically connected to two or more first connection vias that are included in the three or more connection vias and are arranged along a first straight line in a plan view, with the first via reaching the second main surface; and a second via electrically connected to two or more second connection vias that are included in the three or more connection vias and are arranged along a second straight line perpendicular to the first straight line in the plan view, with the second via reaching the second main surface.

Description

Patch antenna and antenna module This disclosure relates to a patch antenna and an antenna module. This application claims priority to Japanese Patent Application No. 2024-052648, filed on March 28, 2024, the contents of which are incorporated herein by reference. Patent Document 1 discloses a patch antenna. Patent Document 1 compares a case where one feed point is connected to a patch without branching with a case where one feed point is connected to a microstrip line, which is then branched in two directions and then connected to a patch. Patent Document 1 discloses that in the former case, when the phase is 90° or 270°, a current flows along the X direction, which is associated with the intended linear polarization, and when the phase is 0° or 180°, a current flows along the Y direction, which is associated with the undesired cross polarization. Patent Document 1 discloses that in the latter case, when the phase is 0° or 180°, a current flows along the X direction, which is associated with the intended linear polarization, and when the phase is 90° or 270°, a current does not flow along the Y direction, which is associated with the undesired cross polarization.

[0064] ,

[0075] ,

[0081] , Figure 1, Figures 7A to 7D, Figure 8 and Figures 12A to 12D). Furthermore, Patent Document 1 discloses that each of the two feed points is connected to a microstrip line, and the microstrip line is branched in two directions and then connected to the patch. The two feed points are connected to two adjacent sides of the patch, respectively (

[0064] ,

[0084] and Figure 18). Patent Document 2 discloses an antenna module. In this antenna module, an antenna element is arranged on an internal layer or on the upper surface of a dielectric substrate, and a ground electrode is arranged on an internal layer of the dielectric substrate. The layer on which the ground electrode is arranged is the internal layer on which the antenna element is arranged or a layer below the surface. Furthermore, a high-frequency signal is supplied to a first feed point and a second feed point. The second feed point is formed at a position symmetrical to the position where the first feed point is formed with respect to the center of the antenna element. This makes it possible to improve the degree of separation between main polarization and cross polarization (

[0003] ,

[0020] ,

[0022] ,

[0023] ,

[0024] ,

[0029] and [Figure 2]). International Publication No. 2021 / 197400 International Publication No. 2020 / 075434 In order to increase the amount of information transmitted by radio waves transmitted and received by a patch antenna, it is effective to have the patch antenna transmit and receive two polarized waves. However, when two polarized waves are transmitted and received by a patch antenna, the isolation between the ports through which the two signals are input and output is reduced. If crosstalk occurs between the two signals, noise will be mixed into the two signals, degrading the quality of the two signals. Patent Documents 1 and 2 do not provide a sufficient solution to this problem. In view of this problem, an object of one aspect of the present disclosure is to provide a patch antenna and an antenna module that can increase isolation between ports through which two signals are input and output when, for example, two polarized waves are transmitted and received, and can suppress crosstalk between the two signals. A patch antenna of a first aspect of the present disclosure comprises a dielectric layer having a first main surface and a second main surface opposite to the first main surface, a patch arranged on the first main surface, a ground arranged on the second main surface, three or more connection vias arranged in the dielectric layer and connected to the patch, a first via arranged in the dielectric layer and reaching the second main surface, the first via being electrically connected to a first two or more connection vias included in the three or more connection vias and arranged along a first straight line in a planar view, and a second via arranged in the dielectric layer and reaching the second main surface, the second via being electrically connected to a second two or more connection vias included in the three or more connection vias and arranged along a second straight line perpendicular to the first straight line in the planar view. An antenna module of a second aspect of the present disclosure comprises a patch antenna of the first aspect of the present disclosure, a circuit for sending signals to the first via and the second via or receiving signals from the first via and the second via, and wiring for electrically connecting the first via and the second via to the circuit. 2. A perspective view schematically illustrating a patch antenna of the first embodiment. A top view schematically illustrating a portion of the patch antenna of the first embodiment. A cross-sectional view schematically illustrating a cross section of a portion of the patch antenna of the first embodiment, taken along the line III-III illustrated in FIG. 2. A cross-sectional view schematically illustrating a cross section of a portion of the patch antenna of the first embodiment, taken along the line IV-IV illustrated in FIG. 2. A cross-sectional view schematically illustrating a cross section of a portion of the patch antenna of the first embodiment, taken along the line V-V illustrated in FIG. 2. A cross-sectional view schematically illustrating a cross section of a portion of the patch antenna of the first embodiment, taken along the line VI-VI illustrated in FIG. 2. S-parameter S of the patch antenna of the first embodiment. １１ 10 is a graph showing the simulation results of the frequency characteristics of the patch antenna of the first embodiment. ２１ 10 is a graph showing the simulation results of the frequency characteristics of the patch antenna of the comparative example. １１ 10 is a graph showing the simulation results of the frequency characteristics of the patch antenna of the comparative example.２１ 1 is a graph showing a simulation result of frequency characteristics of a patch antenna according to a first modified example of the first embodiment; FIG. 2 is a top view schematically showing a part of the patch antenna according to the first modified example of the first embodiment; FIG. 3 is a top view schematically showing a part of the patch antenna according to the first modified example of the first embodiment; and FIG. 4 is an S parameter S of the patch antenna according to the first modified example of the first embodiment. １１ 10 is a graph showing a simulation result of the frequency characteristics of the patch antenna according to the first modification of the first embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of the patch antenna according to the first modification of the first embodiment. １１ 10 is a graph showing a simulation result of the frequency characteristics of the patch antenna according to the first modification of the first embodiment. ２１ 10 is a graph showing a simulation result of frequency characteristics of the patch antenna according to the second modification of the first embodiment; FIG. 11 is a top view schematically showing a part of the patch antenna according to the second modification of the first embodiment; １１ 10 is a graph showing a simulation result of the frequency characteristics of the patch antenna according to the second modification of the first embodiment. ２１ 25. A graph showing simulation results of frequency characteristics of the patch antenna of the third modified example of the first embodiment. A top view schematically showing a patch provided in the patch antenna of the fourth modified example of the first embodiment and the fourth modified example of the second embodiment. A top view schematically showing a patch provided in the patch antenna of the fourth modified example of the first embodiment and the fourth modified example of the second embodiment. A top view schematically showing a patch provided in the patch antenna of the fourth modified example of the first embodiment and the fourth modified example of the second embodiment. A top view schematically showing a patch provided in the patch antenna of the fourth modified example of the first embodiment and the fourth modified example of the second embodiment. A perspective view schematically showing a patch antenna of the second embodiment. A top view schematically showing a part of the patch antenna of the second embodiment. A top view schematically showing a cross section of a part of the patch antenna of the second embodiment, taken along the cutting line XXVI-XXVII drawn in FIG. 25. A top view schematically showing a cross section of a part of the patch antenna of the second embodiment, taken along the cutting line XXVII-XXVII drawn in FIG.１１ 10 is a graph showing the simulation results of the frequency characteristics of the patch antenna of the first embodiment. ２１ 10 is a graph showing a simulation result of frequency characteristics of the patch antenna according to the first modified example of the second embodiment; FIG. 11 is a top view schematically showing a part of the patch antenna according to the first modified example of the second embodiment; FIG. 12 is a top view schematically showing a part of the patch antenna according to the first modified example of the second embodiment; and FIG. 13 is an S parameter S of the patch antenna according to the first modified example of the second embodiment. １１ 10 is a graph showing a simulation result of the frequency characteristics of the patch antenna according to the first modification of the second embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of the patch antenna according to the first modification of the second embodiment. １１ 10 is a graph showing a simulation result of the frequency characteristics of the patch antenna according to the first modification of the second embodiment. ２１ 10 is a graph showing a simulation result of frequency characteristics of the patch antenna according to the second modification of the second embodiment; FIG. 11 is a top view schematically showing a part of the patch antenna according to the second modification of the second embodiment; １１ 10 is a graph showing a simulation result of the frequency characteristics of the patch antenna according to the second modification of the second embodiment. ２１ 10 is a graph showing a simulation result of frequency characteristics of a patch antenna according to a third modification of the second embodiment. FIG. 11 is a top view schematically showing a part of the patch antenna according to the third modification of the second embodiment. FIG. 12 is a cross-sectional view schematically showing an antenna module according to a third embodiment. Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and redundant description will be omitted. 1. First embodiment 1.1 Patch antenna FIG. 1 is a perspective view schematically illustrating a patch antenna according to a first embodiment. FIG. 2 is a top view schematically illustrating a portion of the patch antenna according to the first embodiment. FIG. 3 is a cross-sectional view schematically illustrating a cross section of a portion of the patch antenna according to the first embodiment, taken along the line III-III in FIG. 2. FIG. 4 is a cross-sectional view schematically illustrating a cross section of a portion of the patch antenna according to the first embodiment, taken along the line IV-IV in FIG. 2. FIG. 5 is a cross-sectional view schematically illustrating a cross section of a portion of the patch antenna according to the first embodiment, taken along the line V-V in FIG. 2. FIG. 6 is a cross-sectional view schematically illustrating a cross section of a portion of the patch antenna according to the first embodiment, taken along the line VI-VI in FIG. 2. The patch antenna 1 of the first embodiment shown in Figures 1 to 6 transmits radio waves according to an input signal and outputs a signal according to the received radio waves. The patch antenna 1 is incorporated into a communication module. The patch antenna 1 may also be incorporated into a device other than a communication module. The patch antenna 1 can provide a small and thin antenna when the frequency of the radio waves to be transmitted and received is high. 1 to 6, the patch antenna 1 includes a dielectric layer 11, a patch 12, a ground 13, a plurality of connection vias 14, a first via 15, a second via 16, a first path 17, and a second path 18. In the patch antenna 1 of the first embodiment, the plurality of connection vias 14 is four connection vias. The plurality of connection vias 14 may be five or more connection vias. The dielectric layer 11 has a first main surface 11a and a second main surface 11b. The first main surface 11a and the second main surface 11b are on opposite sides of each other. The first main surface 11a and the second main surface 11b extend in the X direction DX and the Y direction DY. The X direction DX and the Y direction DY are perpendicular to each other. The patch 12 is disposed on the first principal surface 11a. The patch 12 has a film-like shape and serves as a patch surface. The patch 12 has a square shape in a plan view. Therefore, the patch 12 has first two sides 12a and second two sides 12b in a plan view. The first two sides 12a face each other, are parallel to each other, are spaced apart in the X direction DX, and extend in the Y direction DY. The second two sides 12b face each other, are parallel to each other, are spaced apart in the Y direction DY, and extend in the X direction DX. The first two sides 12a and second two sides 12b are perpendicular to each other. The patch 12 is made of a conductor. The conductor is a metal or the like. The ground 13 is disposed on the second principal surface 11b. The ground 13 has a film-like shape and serves as a ground surface. A first antipad 13a and a second antipad 13b are formed on the ground 13. Each of the first antipad 13a and the second antipad 13b has a circular shape in a plan view. Each of the first antipad 13a and the second antipad 13b may have a shape other than a circular shape. In a plan view, an area consisting of a ground arrangement area where the ground 13 is disposed, a first antipad formation area where the first antipad 13a is formed, and a second antipad formation area where the second antipad 13b is formed includes a patch arrangement area where the patch 12 is disposed. As a result, the patch 12 faces the ground 13, the first antipad 13a, and the second antipad 13b across the dielectric layer 11. The area consisting of the ground placement area, the first anti-pad formation area, and the second anti-pad formation area preferably covers the entire area of ​​the second main surface 11b. The ground 13 has a film-like shape and serves as a ground surface. Each of the multiple connection vias 14 has a linear shape. Each of the multiple connection vias 14 is arranged in the dielectric layer 11, extends in the thickness direction of the dielectric layer 11, and reaches the first main surface 11a. One end of each of the multiple connection vias 14 is located between the first main surface 11a and the second main surface 11b. The other end of each of the multiple connection vias 14 is located on the first main surface 11a, and is located in the patch placement area in a plan view. As a result, each of the multiple connection vias 14 is connected to the patch 12. The multiple connection vias 14 are made of a conductor. The conductor is a metal or the like. The plurality of connection vias 14 includes two or more first connection vias 31 and two or more second connection vias 32. In the first embodiment, the first two or more connection vias 31 are two connection vias, and the second two or more connection vias 32 are two connection vias. The first two or more connection vias 31 may be three or more connection vias, and the second two or more connection vias 32 may be three or more connection vias. The first two or more connection vias 31 are arranged at a first interval along a first straight line L1 extending in the Y direction DY in a plan view, and are spaced apart from one another in the Y direction DY. The second two or more connection vias 32 are arranged at a second interval along a second straight line L2 extending in the X direction DX in a plan view, and are spaced apart from one another in the X direction DX. The first straight line L1 is parallel to the first two sides 12a. The second straight line L2 is parallel to the second two sides 12b. The first straight line L1 and the second straight line L2 are perpendicular to each other. The first interval and the second interval are the same. The first two or more connection vias 31 include a first connection via 41 and a second connection via 42, and the second two or more connection vias 32 include a third connection via 43 and a fourth connection via 44. In the patch antenna 1 of the first embodiment, the first two or more connection vias 31 and the second two or more connection vias 32 do not include a common via. Therefore, the first connection via 41 that is closest to the third connection via 43 and the fourth connection via 44 in the first connection via 41 and the second connection via 42, and the third connection via 43 that is closest to the first connection via 41 and the second connection via 42 in the third connection via 43 and the fourth connection via 44, are different vias. Therefore, the third connection via 43 and the fourth connection via 44 are electrically insulated from the first connection via 41 and the second connection via 42. Hereinafter, the center line of the patch 12 in the Y direction DY will be referred to as a first center line C1, and the center line of the patch 12 in the X direction DX will be referred to as a second center line C2. The first connection via 41 and the second connection via 42 are respectively arranged on one side and the other side of the first center line C1 in a plan view. The first connection via 41 and the second connection via 42 are respectively arranged on one side of the second center line C2. The third connection via 43 and the fourth connection via 44 are respectively arranged on one side and the other side of the second center line C2 in a plan view. The third connection via 43 and the fourth connection via 44 are arranged on one side of the first center line C1. The first via 15 has a linear shape. The first via 15 is disposed within the dielectric layer 11, extends in the thickness direction of the dielectric layer 11, and reaches the second main surface 11b. One end of the first via 15 is located between the first main surface 11a and the second main surface 11b. The other end of the first via 15 is located on the second main surface 11b and is located within the first antipad 13a in plan view, preferably at the center of the first antipad 13a. The first via 15 is made of a conductor. The conductor may be a metal or the like. This allows a signal to be input between the other end of the first via 15 and the ground 13. Furthermore, a signal can be output from between the other end of the first via 15 and the ground 13. This allows the other end of the first via 15 and the ground 13 to be used as a first port. The first via 15 is disposed on the first center line C1. The second via 16 has a linear shape. The second via 16 is disposed within the dielectric layer 11, extends in the thickness direction of the dielectric layer 11, and reaches the second main surface 11b. One end of the second via 16 is located between the first main surface 11a and the second main surface 11b. The other end of the second via 16 is located on the second main surface 11b and is located within the second antipad 13b in plan view, preferably at the center of the second antipad 13b. The second via 16 is made of a conductor. The conductor may be a metal or the like. This allows a signal to be input between the other end of the second via 16 and the ground 13. Furthermore, a signal can be output from between the other end of the second via 16 and the ground 13. This allows the other end of the second via 16 and the ground 13 to be used as a second port. The second via 16 is disposed on the second center line C2. The first path 17 has a linear shape. The first path 17 is disposed in the dielectric layer 11 and extends in the surface direction of the dielectric layer 11 and in the Y direction DY. One end of the first path 17 is connected to one end of the first connection via 41. The other end of the first path 17 is connected to one end of the second connection via 42. The middle portion of the first path 17 is connected to one end of the first via 15. As a result, the first path 17 electrically connects the first connection via 41 and the second connection via 42 to the first via 15. As a result, the other end of the first via 15 is electrically connected to the patch 12 via the first via 15, the first path 17, the first connection via 41, and the second connection via 42. As a result, a signal input to the first port can be transmitted from between the other end of the first via 15 and the ground 13 to between the patch 12 and the ground 13. Furthermore, a signal output from the first port can be transmitted from between the patch 12 and the ground 13 to between the other end of the first via 15 and the ground 13. A transmission line consisting of the first via 15, the first path 17, the first connection via 41, and the second connection via 42 extends from the second main surface 11b to a branch point in the dielectric layer 11, branches into two at the branch point, and extends from the branch point to the first two feed points 51 of the patch 12. If the first two or more connection vias 31 are four or more connection vias, the transmission line branches at branch points in each of the layers included in the plurality of layers and reaches the first four or more feed points. The X-direction DX distance from the second center line C2 to the first two feed points 51 affects the feed point impedance of the first two feed points 51. The X-direction DX distance is set so that the feed point impedance of the first two feed points 51 becomes the port impedance. The port impedance is typically 50 Ω. The first path 17 includes a first branch path 61 and a second branch path 62. The first branch path 61 branches from one end of the first via 15 and is connected to one end of the first connecting via 41. The second branch path 62 branches from one end of the first via 15 and is connected to one end of the second connecting via 42. In the patch antenna 1 of the first embodiment, the first length of the first branch path 61 and the second length of the second branch path 62 are the same. The second path 18 has a linear shape. The second path 18 is disposed in the dielectric layer 11 and extends in the plane direction of the dielectric layer 11 and in the X direction DX. One end of the second path 18 is connected to one end of the third connection via 43. The other end of the second path 18 is connected to one end of the fourth connection via 44. The middle portion of the second path 18 is connected to one end of the second via 16. As a result, the second path 18 electrically connects the third connection via 43 and the fourth connection via 44 to the second via 16. As a result, the other end of the second via 16 is electrically connected to the patch 12 via the second via 16, the second path 18, the third connection via 43, and the fourth connection via 44. As a result, a signal input to the second port can be transmitted from between the other end of the second via 16 and the ground 13 to between the patch 12 and the ground 13. Furthermore, a signal output from the second port can be transmitted from between the patch 12 and the ground 13 to between the other end of the second via 16 and the ground 13. A transmission line consisting of the second via 16, the second path 18, the third connection via 43, and the fourth connection via 44 extends from the second main surface 11b to a branch point in the dielectric layer 11, branches into two at the branch point, and extends from the branch point to two second feed points 52 of the patch 12. If the second two or more connection vias 32 are four or more connection vias, the transmission line branches at branch points in each layer included in the plurality of layers and reaches four or more second feed points. The distance in the Y direction DY from the first center line C1 to the second two feed points 52 affects the feed point impedance of the second two feed points 52. The distance in the Y direction DY is set so that the feed point impedance of the second two feed points 52 is the port impedance. The port impedance is typically 50 Ω. The second path 18 includes a third branch path 63 and a fourth branch path 64. The third branch path 63 branches from one end of the second via 16 and is connected to one end of the third connecting via 43. The fourth branch path 64 branches from one end of the second via 16 and is connected to one end of the fourth connecting via 44. In the patch antenna 1 of the first embodiment, the third length of the third branch path 63 and the fourth length of the fourth branch path 64 are the same. When the stripline is disposed on the first principal surface 11a and the end of the stripline is connected to the side of the patch 12, it is difficult to use the feed point impedance as the port impedance. However, when the ends of the first connection via 41, the second connection via 42, the third connection via 43, and the fourth connection via 44 are connected within the plane of the patch 12, it is easy to use the feed point impedance as the port impedance. The port impedance is usually 50 Ω. 1.2 Transmission and reception of X-polarized and Y-polarized waves When a signal is input to the first port, a first current J1 shown in FIG. 2 flows through the patch 12, and a first electric field E1 shown in FIG. 6 is excited in the dielectric layer 11. The direction of the first current J1 is aligned with the X direction DX. The direction of the first electric field E1 is aligned with a direction inclined from the thickness direction of the dielectric layer 11 toward the X direction DX. Furthermore, radio waves are transmitted from electric fields excited near the first two sides 12a, which are included in the excited first electric field E1. The direction of the electric field of the transmitted radio waves is aligned with the X direction DX in a planar view. Therefore, the transmitted radio waves are X-polarized. The reason that the direction of the first current J1 is aligned with the X direction DX and the direction of the first electric field E1 is aligned with a direction inclined from the thickness direction of the dielectric layer 11 toward the X direction DX is because the first two feed points 51 arranged in the Y direction DY are used. When only one feed point is used, the first current J1 flows radially and the first electric field E1 is excited radially. When a signal is input to the second port, a second current J2 shown in FIG. 2 flows through the patch 12, and a second electric field E2 shown in FIG. 5 is excited in the dielectric layer 11. The direction of the second current J2 is aligned with the Y direction DY in a plan view. The direction of the second electric field E2 is aligned with a direction inclined from the thickness direction of the dielectric layer 11 toward the Y direction DY. Furthermore, radio waves are transmitted from electric fields excited near the second two sides 12b, which are included in the excited second electric field E2. The direction of the electric field of the transmitted radio waves is aligned with the Y direction DY. Therefore, the transmitted radio waves are Y-polarized. The reason why the direction of the second current J2 is aligned with the Y direction DY and the direction of the second electric field E2 is aligned with a direction inclined from the thickness direction of the dielectric layer 11 toward the Y direction DY is because two second feed points 52 arranged in the X direction DX are used. If only one feed point is used, a second current J2 flows radially and a second electric field E2 is excited radially. When the patch antenna 1 receives an X-polarized wave, a first current J1 shown in FIG. 2 flows through the patch 12, and a first electric field E1 shown in FIG. 6 is applied to the dielectric layer 11. As a result, the electric fields applied to the positions where the first two feed points 51 are located are in phase. As a result, the signals generated at the first two feed points 51 reinforce each other. As a result, a signal is output from the first port. However, the electric fields applied to the positions where the second two feed points 52 are located are in phase with each other. As a result, the signals generated at the second two feed points 52 weaken each other. As a result, no signal is output from the second port. When the patch antenna 1 receives a Y-polarized wave, a second current J2 shown in FIG. 2 flows through the patch 12, and a second electric field E2 shown in FIG. 5 is applied to the dielectric layer 11. As a result, the electric fields applied to the positions where the second two feed points 52 are located are in phase. As a result, the signals generated at the second two feed points 52 reinforce each other. As a result, a signal is output from the second port. However, the electric fields applied to the positions where the first two feed points 51 are located are in phase with each other. As a result, the signals generated at the first two feed points 51 weaken each other. As a result, no signal is output from the first port. These facts mean that the isolation between the first port and the second port of the patch antenna 1 (hereinafter referred to as "inter-port isolation") is high. When the inter-port isolation of the patch antenna 1 is high, it is possible to suppress the occurrence of crosstalk between the two signals input and output to the first port and the second port when the patch antenna 1 transmits and receives X-polarized waves and Y-polarized waves. The effective wavelength of the radio waves transmitted and received by the patch antenna 1 at the position where the patch 12 is disposed is determined by the dielectric material constituting the dielectric layer 11 and the thickness of the dielectric layer 11. The dielectric material and the thickness are adjusted according to the required gain and size. The distance between the first two sides 12 a and the distance between the second two sides 12 b are set to ½ of the effective wavelength of the radio waves transmitted and received by the patch antenna 1. This allows the patch antenna 1 to resonate with X-polarized waves and Y-polarized waves having a specific frequency, thereby allowing the patch antenna 1 to efficiently transmit and receive X-polarized waves and Y-polarized waves of the specific frequency. 1.3 S-parameters S-parameters S of a two-port circuit having a first port and a second port １１ and S ２２ corresponds to the reflectance. Since the first port and the second port differ only in the polarization they handle, S １１ and S ２２ have the same value. Therefore, in the following, S １１ Only the S-parameters S of the patch antenna 1 are discussed. １１ A small value of σ means that the radiation efficiency of the patch antenna 1 is high. The frequency band that can be used for communication is generally within the range of the S parameter S of the patch antenna 1. １１ is a frequency band in which the noise level is -10 dB or less. S-parameter S in a two-port circuit having a first port and a second port ２１ and S １２ corresponds to the transmittance. Since the first port and the second port differ only in the polarization they handle, S ２１ and S １２have the same value. Therefore, in the following, S ２１ Only the S-parameters S of the patch antenna 1 are discussed. ２１ A small value means that the isolation between the ports of the patch antenna 1 is high. The desired S parameter S of the patch antenna 1 is ２１ is -15 dB or less, and the more desirable S parameter S of the patch antenna 1 ２１ is less than -20 dB. 1.4 Positions in the thickness direction of the first and second paths As shown in FIGS. 3 and 4, the dielectric layer 11 comprises a plurality of layers 71 . The multiple layers 71 are stacked in the thickness direction of the dielectric layer 11 . The multiple layers 71 may include a core layer 81 and a prepreg layer 82. When the multiple layers 71 include the core layer 81 and the prepreg layer 82, the core layer 81 has a thickness greater than the thickness of the prepreg layer 82. The prepreg layer 82 is laminated on the core layer 81. The plurality of layers 71 includes a first layer 91 disposed closest to the patch 12 and a second layer 92 other than the first layer 91. The first layer 91 is a prepreg layer. The first path 17 and the second path 18 are disposed between the first layer 91 and the second layer 92. This allows the first path 17 and the second path 18 to be brought closer to the patch 12. This allows the first path 17 and the second path 18 to be nearly assimilated into the patch 12. This prevents the first path 17 and the second path 18 from functioning as small antennas, and allows the first path 17 and the second path 18 to function solely as transmission lines. This prevents the small antenna formed by the first path 17 and the second path 18 from interfering with the transmission and reception of radio waves by the antenna formed by the patch 12. This increases the radiation efficiency of the patch antenna 1. 1.5 Effect of distance from via to connecting via FIG. 7 shows the S parameter S of the patch antenna of the first embodiment. １１8 is a graph showing the simulation results of the frequency characteristics of the patch antenna of the first embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of 7 and 8, the lengths of the first two sides 12a and the second two sides 12b of the patch 12 are 2.7 mm, the distance in the X direction DX from the second center line C2 to the first via 15, the first connecting via 41, and the second connecting via 42, and the distance in the Y direction DY from the first center line C1 to the second via 16, the third connecting via 43, and the fourth connecting via 44 are 0.9 mm in plan view, and the dielectric material constituting the dielectric layer 11 is a dielectric material manufactured by Resonac Corporation (Minato-ku, Tokyo, Japan). 1 shows a simulation result in which the dielectric layer 11 is MCL-HS100 manufactured by Epson Corporation, the thickness of the dielectric layer 11 is 725 μm, the radii of the first antipad 13 a and the second antipad 13 b are 350 μm in plan view, the radii r of the first connecting via 41, the second connecting via 42, the third connecting via 43 and the fourth connecting via 44 are 25 μm in plan view, and the radii R of the first via 15 and the second via 16 are 75 μm in plan view. 7 and 8 show simulation results when the distance L, which is the Y-direction DY distance from the first via 15 to the first connecting via 41, the Y-direction DY distance from the first via 15 to the second connecting via 42, the X-direction DX distance from the second via 16 to the third connecting via 43, and the X-direction DX distance from the second via 16 to the fourth connecting via 44, is 200 μm, 400 μm, and 600 μm in plan view. As shown in FIG. 7, the S parameter S of the patch antenna 1 １１ becomes larger as the distance L becomes longer. In other words, the radiation efficiency of the patch antenna 1 becomes lower as the distance L becomes longer. The reason why the radiation efficiency of the patch antenna 1 becomes lower as the distance L becomes longer is that the longer the distance L, the larger the discontinuous parts that cause reflections. As shown in FIG. 8, the S parameter S of the patch antenna 1 ２１does not depend strongly on the distance L, but becomes smaller as the distance L becomes longer. In other words, the inter-port isolation of the patch antenna 1 becomes higher as the distance L becomes longer. The reason why the inter-port isolation of the patch antenna 1 becomes higher as the distance L becomes longer is because the distribution of the electric field within the patch arrangement area becomes more uniform as the distance L becomes longer. S parameter S of patch antenna 1 １１ In the frequency characteristics of the patch antenna 1, the S parameter S １１ The deeper the dip, the higher the radiation efficiency of the patch antenna 1. However, the S parameter S １１ In the frequency characteristics of the patch antenna 1, the S parameter S １１ The deeper the dip, the stronger the electric field excited between the patch 12 and the ground 13. Therefore, the signal output from a port different from the port to which the signal is input becomes stronger. This reduces the isolation between the ports of the patch antenna 1. For this reason, in the evaluation of the patch antenna 1, the S parameter S of the patch antenna 1 is １１ The S parameter S of the patch antenna 1 in a frequency band where ２１ or the S parameter S of the patch antenna 1 ２１ The S parameter S of the patch antenna 1 in a frequency band where １１ The smaller the value, the better the evaluation. 1.6 Comparison of branching and non-branching FIG. 9 shows the S-parameters S of the patch antenna of the comparative example. １１ 10 is a graph showing the simulation results of the frequency characteristics of the patch antenna of the comparative example. ２１ 10 is a graph showing a simulation result of the frequency characteristics of The patch antenna of the comparative example differs from the patch antenna 1 of the first embodiment in that it does not have the first connecting via 41, the second connecting via 42, the third connecting via 43, the fourth connecting via 44, the first path 17 and the second path 18, and the first via 15 and the second via 16 are directly connected to the patch 12. 9 and 10 show simulation results when the radius R of the first via 15 and the second via 16 is 25 μm, 40 μm, 50 μm, and 75 μm in plan view. Table 1 shows the S parameters S of the patch antennas of Comparative Examples 1 and 2 and the patch antennas 1 of Examples 1 and 2. １１ The minimum value of the S parameter S １１ The S parameter S at the lower limit frequency of the frequency band where ２１ and the S parameter S at the upper limit frequency of the frequency band ２１ Indicates the value of In the patch antennas of Comparative Examples 1 and 2, the radii R are 75 μm and 40 μm, respectively. １１ are the S parameters S of the patch antennas of Comparative Examples 1 and 2. １１ In the patch antennas 1 of Examples 1 and 2, the distance L is 400 μm and 600 μm, respectively. From Table 1, the S parameter S of the patch antenna 1 of Example 1 is １１ The minimum value of the S parameter S of the patch antenna of Comparative Example 1 is １１ and the S parameter S of the patch antenna 1 of Example 1 is smaller than the minimum value of ２１ The value of the S parameter S of the patch antenna of Comparative Example 1 ２１ That is, it can be seen that the radiation efficiency of the patch antenna 1 of Example 1 is higher than the radiation efficiency of the patch antenna of Comparative Example 1, and the inter-port isolation of the patch antenna 1 of Example 1 is higher than the inter-port isolation of the patch antenna of Comparative Example 1. Furthermore, from Table 1, the S parameter S of the patch antenna 1 of Example 2 is １１ The minimum value of the S parameter S of the patch antenna of Comparative Example 2 is １１ and the S parameter S of the patch antenna in Example 2 is smaller than the minimum value of ２１ The value of the S parameter S of the patch antenna of Comparative Example 2２１ That is, it can be seen that the radiation efficiency of the patch antenna 1 of Example 2 is higher than the radiation efficiency of the patch antenna of Comparative Example 2, and the inter-port isolation of the patch antenna 1 of Example 2 is generally the same as the inter-port isolation of the patch antenna of Comparative Example 2. 1.7 First Modification of the First Embodiment 11 and 12 are top views schematically illustrating a part of a patch antenna according to a first modified example of the first embodiment. In the patch antenna 1 of the first embodiment, as shown in Figure 2, the first via 15 is arranged on the first center line C1 in a planar view, and the second via 16 is arranged on the second center line C2 in a planar view. In contrast, in the patch antenna 1a of the first modified example of the first embodiment, as shown in Figures 11 and 12, the first via 15 is arranged on the other side of the first center line C1 in a plan view, and the second via 16 is arranged on the other side of the second center line C2 in a plan view. This separates the first via 15 and the second via 16 from each other. This weakens the electromagnetic field coupling between the first via 15 and the second via 16. This increases the inter-port isolation of the patch antenna 1a. When the first via 15 is arranged on the other side of the first center line C1 and the distance from the first via 15 to the first connecting via 41 and the distance from the first via 15 to the second connecting via 42 are different from each other, the phases of the signals fed to the first two feeding points 51 are different from each other. When the second via 16 is positioned on the other side of the second center line C2 and the distance from the second via 16 to the third connecting via 43 and the distance from the second via 16 to the fourth connecting via 44 are different from each other, the phases of the signals supplied to the second two power supply points 52 are different from each other. Furthermore, in the patch antenna 1 of the first embodiment, as shown in Figure 2, the first length of the first branch path 61 and the second length of the second branch path 62 are the same, and the third length of the third branch path 63 and the fourth length of the fourth branch path 64 are the same. 11 , in the patch antenna 1a according to the first modification of the first embodiment, the second length of the second branch path 62 may be longer than the first length of the first branch path 61, and the fourth length of the fourth branch path 64 may be longer than the third length of the third branch path 63. This can eliminate the shortage of the second length caused by the first via 15 being disposed on the other side of the first center line C1, and can eliminate the shortage of the third length caused by the second via 16 being disposed on the other side of the second center line C2. This can increase the inter-port isolation of the patch antenna 1a. 12 , in the patch antenna 1a of the first modified example of the first embodiment, the second length of the second branch path 62 may be shorter than the first length of the first branch path 61, and the fourth length of the fourth branch path 64 may be shorter than the third length of the third branch path 63. This brings the first two feed points 51 closer to the first via 15, and the second two feed points 52 closer to the second via 16. This makes it possible to reduce losses in the second branch path 62 and the fourth branch path 64, and to increase the radiation efficiency of the patch antenna 1a. FIG. 13 shows the S parameter S of the patch antenna according to the first modification of the first embodiment. １１ 14 is a graph showing the simulation results of the frequency characteristics of the patch antenna according to the first modification of the first embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of 13 and 14 show simulation results when the distance L is 400 μm, the first two feed points 51 are at the same distance from the first center line C1, and the second two feed points 52 are at the same distance from the second center line C2. Figures 13 and 14 show simulation results when the deviation S_parallel, which is the deviation amount to the other side of the first center line C1 of the first via 15 and the deviation amount to the other side of the second center line C2 of the second via 16, is -200 μm, -100 μm, 0 μm, 100 μm, and 200 μm. As shown in FIG. 13, the S parameter S of the patch antenna 1a is １１ is smallest when the displacement S_parallel is 100 μm. That is, the radiation efficiency of the patch antenna 1 is highest when the displacement S_parallel is 100 μm. As shown in FIG. 14, the S parameter S of the patch antenna 1a is ２１ is smallest when the shift amount S_parallel is 100 μm. That is, the inter-port isolation of the patch antenna 1 a is highest when the shift amount S_parallel is 100 μm. FIG. 15 shows the S parameter S of the patch antenna according to the first modification of the first embodiment. １１ 16 is a graph showing the simulation results of the frequency characteristics of the patch antenna according to the first modification of the first embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of 15 and 16 show the simulation results when the deviation amount S_parallel is 100 μm. 15 and 16 show simulation results when the length difference ΔL, which is the difference between the second length of the second branch path 62 and the first length of the first branch path 61 and the difference between the fourth length of the fourth branch path 64 and the third length of the third branch path 63, is −400 μm, −200 μm, and 0 μm. As shown in FIG. 15, the S parameter S of the patch antenna 1a is １１ is smallest when the length difference ΔL is −200 μm. That is, the radiation efficiency of the patch antenna 1a is highest when the length difference ΔL is −200 μm. This means that the radiation efficiency of the patch antenna 1a is highest when the first two feed points 51 are arranged symmetrically with respect to the first center line C1 and the second two feed points 52 are arranged symmetrically with respect to the second center line C2. As shown in FIG. 16, the S parameter S of the patch antenna 1a is ２１is smallest when the length difference ΔL is 0 μm. In other words, the inter-port isolation of the patch antenna 1a is highest when the length difference ΔL is 0 μm. The reason for this is that when the length difference ΔL is 0 μm, the Y-polarized signals generated at the first two feed points 51 weaken each other, and the X-polarized signals generated at the second two feed points 52 weaken each other. However, the S parameter S of the patch antenna 1a １１ At frequencies lower than the frequency at which is minimum, the S-parameter S ２１ shows the opposite trend. Table 2 shows the S parameters S of the patch antenna 1a of Example 3. １１ The minimum value of the S parameter S １１ The S parameter S at the lower limit frequency of the frequency band where ２１ and the S parameter S at the upper limit frequency of the frequency band ２１ Indicates the value of The configuration of the patch antenna 1a of Example 3 is as follows: １１ is the S parameter S of the patch antenna of Comparative Example 1 １１ In the patch antenna 1a of the third embodiment, the amount of deviation S_parallel is 100 μm, and the length difference ΔL is −200 μm. From Tables 1 and 2, the S parameter S of the patch antenna 1a of Example 3 is １１ The minimum value of the S parameter S of the patch antenna of Comparative Example 1 is １１ and the S parameter S at the upper limit frequency of the patch antenna 1a of Example 3 is smaller than the minimum value of ２１ is the S parameter S at the upper limit frequency of the patch antenna of Comparative Example 1 ２１It can be seen that the radiation efficiency of the patch antenna 1a of Example 3 is higher than that of the patch antenna of Comparative Example 1, and the inter-port isolation at the upper limit frequency of the patch antenna 1a of Example 3 is higher than that of the patch antenna of Comparative Example 1. In addition, the S parameter S of the patch antenna 1a of Example 3 is ２１ The fluctuation of the S parameter S of the patch antenna of Comparative Example 1 ２１ It can be seen that the variation in inter-port isolation of the patch antenna 1a of Example 3 is smaller than the variation in inter-port isolation of the patch antenna of Comparative Example 1. When the variation in inter-port isolation of the patch antenna 1a is small in this way, there is no need to set circuit constants according to frequency when suppressing leakage components on the circuit connected to the patch antenna 1a side. This makes it possible to simplify the circuit, reduce the size of the circuit, and reduce the power consumption of the circuit. 1.8 Second Modification of the First Embodiment FIG. 17 is a top view schematically illustrating a part of a patch antenna according to a second modification of the first embodiment. In the patch antenna 1 of the first embodiment, as shown in Figure 2, the first via 15 is arranged along a first straight line L1 in a planar view, and the second via 16 is arranged along a second straight line L2 in a planar view. 17, in the patch antenna 1b of the second modified example of the first embodiment, the first via 15 is shifted from the first straight line L1 in a direction approaching the second center line C2 in a plan view, and the second via 16 is shifted from the second straight line L2 in a direction approaching the first center line C1 in a plan view. Therefore, the first via 15 is disposed between the first straight line L1 and the second center line C2 in a plan view, and the second via 16 is disposed between the second straight line L2 and the first center line C1 in a plan view. When the first via 15 is shifted in a direction away from the second center line C2 in a plan view and the second via 16 is shifted in a direction away from the first center line C1 in a plan view, the area of ​​the ground 13 that strongly contributes to the transmission and reception of radio waves is removed by the first anti-pad 13a and the second anti-pad 13b. As a result, the radiated energy decreases and the directivity pattern of the patch antenna 1b is distorted. FIG. 18 shows the S parameter S of the patch antenna according to the second modification of the first embodiment. １１ 19 is a graph showing the simulation results of the frequency characteristics of the patch antenna according to the second modification of the first embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of 18 and 19 show the simulation results when the length difference ΔL is 0 μm and the deviation amount S_parallel is 0 μm. Figures 18 and 19 show simulation results when the deviation S_perp, which is the deviation of the first via 15 from the first straight line L1 in the direction toward the second center line C2 and the deviation of the second via 16 from the second straight line L2 in the direction toward the first center line C1, is -200 μm, -100 μm, 0 μm, 100 μm, and 200 μm. As shown in FIG. 18, the S parameter S of the patch antenna 1b is １１ The frequency at which the S parameter S of the patch antenna 1b is minimum becomes lower as the deviation S_perp increases. １１ becomes smaller as the amount of deviation S_perp increases within a range where the amount of deviation S_perp is smaller than 0 μm, and becomes larger as the amount of deviation S_perp increases within a range where the amount of deviation S_perp is larger than 0 μm. That is, the radiation efficiency of patch antenna 1b becomes higher as the amount of deviation S_perp increases within a range where the amount of deviation S_perp is smaller than 0 μm, and becomes lower as the amount of deviation S_perp increases within a range where the amount of deviation S_perp is larger than 0 μm. As shown in FIG. 19, the S parameter S of the patch antenna 1b is ２１In other words, the inter-port isolation of the patch antenna 1b increases as the amount of deviation S_perp increases. Table 3 shows the S parameters S of the patch antenna 1b of Example 4. １１ The minimum value of the S parameter S １１ The S parameter S at the lower limit frequency of the frequency band where ２１ and the S parameter S at the upper limit frequency of the frequency band ２１ Indicates the value of The configuration of the patch antenna 1b of Example 4 is as follows: １１ is the S parameter S of the patch antenna of Comparative Example 2 １１ In the patch antenna 1b of the fourth embodiment, the deviation amount S_perp is 100 μm. From Tables 1 and 3, the S parameter S of the patch antenna 1b of Example 4 is １１ The minimum value of the S parameter S of the patch antenna of Comparative Example 2 is １１ and the S parameter S of the patch antenna 1b of Example 4 is smaller than the minimum value of ２１ is the S parameter S of the patch antenna of Comparative Example 2 ２１ That is, it can be seen that the radiation efficiency of the patch antenna 1b of Example 4 is higher than the radiation efficiency of the patch antenna of Comparative Example 2, and the inter-port isolation of the patch antenna 1b of Example 4 is higher than the inter-port isolation of the patch antenna of Comparative Example 2. 1.9 Third Modification of the First Embodiment FIG. 20 is a top view schematically illustrating a part of a patch antenna according to a third modified example of the first embodiment. In the patch antenna 1 of the first embodiment, as shown in Figure 2, the first spacing at which two or more first connection vias 31 are arranged and the second spacing at which two or more second connection vias 32 are arranged are the same spacing. In contrast, in the patch antenna 1c of the third modified example of the first embodiment, as shown in FIG. 20 , the first interval at which two or more first connection vias 31 are arranged and the second interval at which two or more second connection vias 32 are arranged are different from each other. Alternatively, the first interval and the second interval may be the same, and other locations may be adjusted. For example, the position of the first via 15 or the second via 16 may be the same as the position of the first via 15 or the second via 16 in the first or second modified example. This allows the crosstalk characteristics, isolation characteristics, etc. of the first port and the second port to be different from each other, thereby canceling the differences in the crosstalk characteristics, isolation characteristics, etc. between the first circuit connected to the first port and the second circuit, and the crosstalk characteristics, isolation characteristics, etc. between the second circuit and the second port to be consistent. Furthermore, even when the patch 12 has a rectangular shape, the crosstalk characteristics, isolation characteristics, etc. of the first port and the crosstalk characteristics, isolation characteristics, etc. of the second port can be made uniform. 1.10 Fourth Modification of the First Embodiment 21, 22, and 23 are top views schematically illustrating patches provided in a patch antenna according to a fourth modification of the first embodiment. In the patch antenna 1 of the first embodiment, the patch 12 has a square shape in a plan view as shown in Fig. 2. However, the patch 12 may have a shape other than a square. Therefore, in the fourth variant of the first embodiment, for example, the patch 12 may have an octagonal shape obtained by diagonally cutting off the corners of a square shape as shown in FIG. 21 , or may have a shape obtained by rounding the corners of a square shape as shown in FIG. 22 , or may have a shape obtained by forming notches in the corners of a square shape as shown in FIG. 23 . 2. Second embodiment 2.1 Differences from the first embodiment The following describes the differences between the second embodiment and the first embodiment. For points that are not described, the second embodiment also employs the same configuration as that employed in the first embodiment. Fig. 24 is a perspective view schematically illustrating a patch antenna of the second embodiment. Fig. 25 is a top view schematically illustrating a portion of the patch antenna of the second embodiment. Fig. 26 is a top view schematically illustrating a cross section of a portion of the patch antenna of the second embodiment, taken along the cutting line XXVI-XXVII depicted in Fig. 25. Fig. 27 is a top view schematically illustrating a cross section of a portion of the patch antenna of the second embodiment, taken along the cutting line XXVII-XXVII depicted in Fig. 25. 24 to 27, in the patch antenna 2 of the second embodiment, the plurality of connection vias 14 is three connection vias. Furthermore, the first two or more connection vias 31 and the second two or more connection vias 32 include a shared via, and the first connection via 41 and the third connection via 43 are shared vias. This allows the number of the plurality of connection vias 14 to be reduced. 2.2 Effect of via and connecting via radius FIG. 28 shows the S parameter S of the patch antenna of the second embodiment. １１ 29 is a graph showing the simulation results of the frequency characteristics of the patch antenna of the second embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of 28 and 29 show simulation results in which the lengths of the first two sides 12a and the second two sides 12b of the patch 12 are 2.7 mm, the X-direction DX distance from the second center line C2 to the first via 15, the first connecting via 41, and the second connecting via 42 and the Y-direction DY distance from the first center line C1 to the second via 16, the third connecting via 43, and the fourth connecting via 44 are 0.9 mm in plan view, the dielectric material constituting the dielectric layer 11 is MCL-HS100 manufactured by Resonac Inc. (Minato-ku, Tokyo, Japan), the thickness of the dielectric layer 11 is 725 μm, and the radii of the first antipad 13a and the second antipad 13b are 350 μm in plan view. 28 and 29 show simulation results for the cases where the combinations (r, R) of the radii r of the first connection via 41, the second connection via 42, the third connection via 43, and the fourth connection via 44 and the radii R of the first via 15 and the second via 16 are (25 μm, 25 μm), (25 μm, 50 μm), (25 μm, 75 μm), (25 μm, 100 μm), (50 μm, 50 μm), (50 μm, 75 μm), (50 μm, 100 μm), (75 μm, 75 μm), and (75 μm, 100 μm). Table 4 shows the S parameters S of the patch antennas of Comparative Examples 1 and 2 and the patch antennas 2 of Examples 5 and 6 mentioned in the description of the first embodiment. １１ The minimum value of the S parameter S １１ The S parameter S at the lower limit frequency of the frequency band where ２１ and the S parameter S at the upper limit frequency of the frequency band ２１ Indicates the value of The configuration of the patch antenna 2 in Examples 5 and 6 is as follows: １１ are the S parameters S of the patch antennas of Comparative Examples 1 and 2. １１In the patch antenna 2 of Example 5, the combination (r, R) of the radius r and the radius R is (75 μm, 75 μm). In the patch antenna 2 of Example 6, the combination (r, R) of the radius r and the radius R is (50 μm, 75 μm). From Table 4, the S parameter S of the patch antenna 2 of Example 5 １１ The minimum value of the S parameter S of the patch antenna of Comparative Example 1 is １１ and the S parameter S of the patch antenna 2 of Example 5 ２１ The value of the S parameter S of the patch antenna of Comparative Example 1 ２１ That is, it can be seen that the radiation efficiency of the patch antenna 2 of Example 5 is the same as the radiation efficiency of the patch antenna of Comparative Example 1, and that the inter-port isolation of the patch antenna 2 of Example 5 is higher than the inter-port isolation of the patch antenna of Comparative Example 1. Furthermore, from Table 4, the S parameter S of the patch antenna 2 of Example 6 is １１ The minimum value of the S parameter S of the patch antenna of Comparative Example 2 is １１ The value of the S parameter S21 of the patch antenna 2 of Example 6 is smaller than the minimum value of the S parameter S ２１ That is, it can be seen that the radiation efficiency of the patch antenna 2 of Example 6 is higher than the radiation efficiency of the patch antenna of Comparative Example 2, and the inter-port isolation of the patch antenna 2 of Example 6 is generally the same as the inter-port isolation of the patch antenna of Comparative Example 2. 2.3 First Modification of the Second Embodiment 30 and 31 are top views schematically illustrating a part of a patch antenna according to a first modified example of the second embodiment. In the patch antenna 2 of the second embodiment, as shown in Figure 25, the first via 15 is arranged on the first center line C1 in a planar view, and the second via 16 is arranged on the second center line C2 in a planar view. In contrast, in the patch antenna 2a of the first modified example of the second embodiment, as shown in Figures 30 and 31, the first via 15 is arranged on the other side of the first center line C1 in a plan view, and the second via 16 is arranged on the other side of the second center line C2 in a plan view. This separates the first via 15 and the second via 16 from each other. This weakens the electromagnetic field coupling between the first via 15 and the second via 16. This increases the inter-port isolation of the patch antenna 2a. When the first via 15 is arranged on the other side of the first center line C1 and the distance from the first via 15 to the first connecting via 41 and the distance from the first via 15 to the second connecting via 42 are different from each other, the phases of the signals fed from the first two feeding points 51 are different from each other. When the second via 16 is positioned on the other side of the second center line C2 and the distance from the second via 16 to the third connecting via 43 and the distance from the second via 16 to the fourth connecting via 44 are different from each other, the phases of the signals fed from the second two feeding points 52 are different from each other. Furthermore, in the patch antenna 2 of the second embodiment, as shown in Figure 25, the first length of the first branch path 61 and the second length of the second branch path 62 are the same, and the third length of the third branch path 63 and the fourth length of the fourth branch path 64 are the same. 30 , in the patch antenna 2a according to the first modified example of the second embodiment, the second length of the second branch path 62 may be longer than the first length of the first branch path 61, and the fourth length of the fourth branch path 64 may be longer than the third length of the third branch path 63. This can eliminate the shortage of the second length caused by the first via 15 being located on the other side of the first center line C1, and can eliminate the shortage of the third length caused by the second via 16 being located on the other side of the second center line C2. This can increase the inter-port isolation of the patch antenna 2a. 31 , in the patch antenna 2a of the first modified example of the second embodiment, the second length of the second branch path 62 may be shorter than the first length of the first branch path 61, and the fourth length of the fourth branch path 64 may be shorter than the third length of the third branch path 63. This brings the first two feed points 51 closer to the first via 15, and the second two feed points 52 closer to the second via 16. This makes it possible to increase the radiation efficiency of the patch antenna 2a. FIG. 32 shows the S parameter S of the patch antenna according to the first modification of the second embodiment. １１ 33 is a graph showing the simulation results of the frequency characteristics of the patch antenna according to the first modified example of the second embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of 32 and 33 show simulation results when the distance L is 400 μm, the first two feed points 51 are at the same distance from the first center line C1, and the second two feed points 52 are at the same distance from the second center line C2. Figures 32 and 33 show simulation results when the deviation S_parallel, which is the deviation amount to the other side of the first center line C1 of the first via 15 and the deviation amount to the other side of the second center line C2 of the second via 16, is -200 μm, -100 μm, 0 μm, 100 μm, and 200 μm. As shown in FIG. 32, the S parameter S of the patch antenna 2a is １１ is smallest when the displacement S_parallel is 100 μm. That is, the radiation efficiency of the patch antenna 2 a is highest when the displacement S_parallel is 100 μm. As shown in FIG. 33, the S parameter S of the patch antenna 2a is ２１ is smallest when the shift amount S_parallel is 100 μm. That is, the inter-port isolation of the patch antenna 2 a is highest when the shift amount S_parallel is 100 μm. FIG. 34 shows the S parameter S of the patch antenna according to the first modification of the second embodiment.１１ 35 is a graph showing the simulation results of the frequency characteristics of the patch antenna according to the first modified example of the second embodiment. ２１ 10 is a graph showing a simulation result of the frequency characteristics of 34 and 35 show the simulation results when the deviation amount S_parallel is 100 μm. 34 and 35 show simulation results when the length difference ΔL, which is the difference between the second length of the second branch path 62 and the first length of the first branch path 61 and the difference between the fourth length of the fourth branch path 64 and the third length of the third branch path 63, is −400 μm, −300 μm, −200 μm, −100 μm, and 0 μm. As shown in FIG. 34, the S parameter S of the patch antenna 2a is １１ becomes larger as the length difference ΔL becomes larger. That is, the radiation efficiency of the patch antenna 2a becomes lower as the length difference ΔL becomes larger. The reason for this is that when the first two feed points 51 are arranged near the first center line C1, power feeding can be performed more efficiently and loss due to the first path 17 and the second path 18 can be reduced compared to when the first two feed points 51 are not arranged near the first center line C1. As shown in FIG. 35, the S parameter S of the patch antenna 2a is ２１ becomes smaller as the length difference ΔL becomes larger. In other words, the inter-port isolation of patch antenna 2a becomes higher as the length difference ΔL becomes larger. The reason for this is that when the length difference ΔL is 0 μm, the Y-polarized signals generated at the first two feed points 51 weaken each other, and the X-polarized signals generated at the second two feed points 52 weaken each other. Table 5 shows the S parameters S of the patch antenna 2a of Example 7. １１ The minimum value of the S parameter S １１ The S parameter S at the lower limit frequency of the frequency band where ２１ and the S parameter S at the upper limit frequency of the frequency band ２１ Indicates the value of The configuration of the patch antenna 1 of Example 7 is as follows: １１ is the S parameter S of the patch antenna of Comparative Example 1 １１ In the patch antenna 2a of Example 7, the amount of deviation S_parallel is 100 μm, and the length difference ΔL is −100 μm. From Tables 4 and 5, the S parameter S of the patch antenna 2a of Example 7 １１ The minimum value of the S parameter S of the patch antenna of Comparative Example 1 is １１ and the S parameter S at the upper limit frequency of the patch antenna 2a of Example 7 is the same as the minimum value of ２１ The value of the S parameter S at the upper limit frequency of the patch antenna of Comparative Example 1 is ２１ It can be seen that the radiation efficiency of the patch antenna 2a of Example 7 is the same as that of the patch antenna of Comparative Example 1, and that the inter-port isolation at the upper limit frequency of the patch antenna 2a of Example 7 is higher than the inter-port isolation at the upper limit frequency of the patch antenna of Comparative Example 1. In addition, the S parameter S of the patch antenna 2a of Example 7 １１ The S parameter S of the patch antenna 2a of Example 7 in the frequency band where ２１ The fluctuation of the S parameter S of the patch antenna of Comparative Example 1 １１ The S parameter S of the patch antenna of Comparative Example 1 in the frequency band where ２１It can be seen that the variation in inter-port isolation of the patch antenna 2a of Example 7 in the frequency band where the radiation efficiency of the patch antenna 2a of Example 7 is high is smaller than the variation in inter-port isolation of the patch antenna of Comparative Example 1 in the frequency band where the radiation efficiency of the patch antenna of Comparative Example 1 is high. When the variation in inter-port isolation of the patch antenna 2a is small in this way, there is no need to set circuit constants according to frequency when suppressing leakage components on the circuit connected to the patch antenna 2a side. This makes it possible to simplify the circuit, reduce the size of the circuit, and reduce the power consumption of the circuit. 2.4 Second Modification of the Second Embodiment FIG. 36 is a top view schematically illustrating a part of a patch antenna according to a second modification of the second embodiment. In the patch antenna 2 of the second embodiment, as shown in Figure 25, the first via 15 is arranged along a first straight line L1 in a planar view, and the second via 16 is arranged along a second straight line L2 in a planar view. In contrast, in the patch antenna 2b of the second modified example of the second embodiment, as shown in FIG. 36 , the first via 15 is shifted from the first straight line L1 in a direction approaching the second center line C2 in a plan view, and the second via 16 is shifted from the second straight line L2 in a direction approaching the first center line C1 in a plan view. Therefore, the first via 15 is disposed between the first straight line L1 and the second center line C2 in a plan view, and the second via 16 is disposed between the second straight line L2 and the first center line C1 in a plan view. This brings the first via 15 and the second via 16 closer to each other. This strengthens the electromagnetic field coupling between the first via 15 and the second via 16. This reduces the inter-port isolation of the patch antenna 2b. Meanwhile, the angle formed by the first branch path 61 and the third branch path 63, which are located close to each other, is smaller than 90°. As a result, it becomes difficult for a signal to propagate from one of the first via 15 and the second via 16 to the other of the first via 15 and the second via 16 via the first branch path 61 and the third branch path 63. This increases the inter-port isolation of the patch antenna 2b. The latter effect of increasing the inter-port isolation is stronger than the former effect of decreasing the inter-port isolation. Therefore, when the first via 15 is disposed between the first straight line L1 and the second center line C2 and the second via 16 is disposed between the second straight line L2 and the first center line C1, the inter-port isolation of the patch antenna 2b can be increased. When the first via 15 is shifted in a direction away from the second center line C2 in a plan view and the second via 16 is shifted in a direction away from the first center line C1 in a plan view, the area of ​​the ground 13 that strongly contributes to the transmission and reception of radio waves is removed by the first anti-pad 13a and the second anti-pad 13b. As a result, the radiated energy decreases and the directivity pattern of the patch antenna 2b is distorted. FIG. 37 shows the S parameter S of the patch antenna according to the second modification of the second embodiment. １１ 38 is a graph showing the simulation results of the frequency characteristics of the patch antenna according to the second modification of the second embodiment. ２１10 is a graph showing a simulation result of the frequency characteristics of 37 and 38 show the simulation results when the length difference ΔL is 0 μm and the deviation amount S_parallel is 0 μm. Figures 37 and 38 show simulation results when the deviation S_perp, which is the deviation from the first straight line L1 of the first via 15 in the direction approaching the second center line C2 and the deviation from the second straight line L2 of the second via 16 in the direction approaching the first center line C1, is -200 μm, -100 μm, 0 μm, 100 μm, and 200 μm. As shown in FIG. 37, the S parameter S of the patch antenna 2b is １１ The frequency at which the S parameter S of the patch antenna 2b is minimum becomes lower as the deviation S_perp increases. １１ becomes smaller as the deviation amount S_perp increases within a range where the deviation amount S_perp is smaller than -100 μm, and becomes larger as the deviation amount S_perp increases within a range where the deviation amount S_perp is larger than -100 μm. That is, the radiation efficiency of patch antenna 2b becomes higher as the deviation amount S_perp increases within a range where the deviation amount S_perp is smaller than -100 μm, and becomes lower as the deviation amount S_perp increases within a range where the deviation amount S_perp is larger than -100 μm. As shown in FIG. 38, the S parameter S of the patch antenna 2b is ２１ In other words, the inter-port isolation of the patch antenna 2b increases as the displacement S_perp increases. Table 6 shows the S parameters S of the patch antenna 2b of Example 8. １１ The minimum value of the S parameter S １１ The S parameter S at the lower limit frequency of the frequency band where ２１ and the S parameter S at the upper limit frequency of the frequency band ２１ Indicates the value of The configuration of the patch antenna 2b of Example 8 is as follows: １１ is the S parameter S of the patch antenna of Comparative Example 2 １１ In the patch antenna 2b of Example 8, the deviation amount S_perp is 100 μm. From Tables 4 and 6, the S parameter S of the patch antenna 2b of Example 8 is １１ The minimum value of the S parameter S of the patch antenna of Comparative Example 2 is １１ and the S parameter S of the patch antenna 2b of Example 8 is smaller than the minimum value of ２１ The value of the S parameter S of the patch antenna of Comparative Example 2 ２１ That is, it can be seen that the radiation efficiency of the patch antenna 2b of Example 8 is higher than the radiation efficiency of the patch antenna of Comparative Example 2, and the inter-port isolation of the patch antenna 2b of Example 8 is higher than the inter-port isolation of the patch antenna of Comparative Example 2. 2.5 Third Modification of the Second Embodiment FIG. 39 is a top view schematically illustrating a part of a patch antenna according to a third modified example of the second embodiment. In the patch antenna 2 of the second embodiment, as shown in Figure 25, the first spacing at which two or more first connection vias 31 are arranged and the second spacing at which two or more second connection vias 32 are arranged are the same spacing. In contrast, in a patch antenna 2c according to a third modification of the second embodiment, as shown in FIG. 39 , the first interval at which two or more first connection vias 31 are arranged and the second interval at which two or more second connection vias 32 are arranged are different from each other. In FIG. 39 , to make the first interval and the second interval different, the distance from the first center line C1 to the second straight line L2 and the distance from the second center line C2 to the first straight line L1 are made different from each other. However, the distance from the first center line C1 to the second straight line L2 and the distance from the second center line C2 to the first straight line L1 may be the same, and adjustments may be made at other locations. For example, only the relationship between the first via 15 and the multiple connection vias 14 may be the same as the relationship between the first via 15 and the multiple connection vias 14 in the first or second modification. As a result, when the crosstalk characteristics, isolation characteristics, etc. between a first circuit connected to a first port and a second circuit connected to a second port are different from each other, the crosstalk characteristics, isolation characteristics, etc. of the first port and the second port can be made different from each other to cancel the differences in the crosstalk characteristics, isolation characteristics, etc. between the first circuit and the second circuit. As a result, the overall crosstalk characteristics, isolation characteristics, etc. of the first port and the first circuit and the overall crosstalk characteristics, isolation characteristics, etc. of the second port and the second circuit can be made uniform. Furthermore, even when the patch 12 has a rectangular shape, the crosstalk characteristics, isolation characteristics, etc. of the first port and the crosstalk characteristics, isolation characteristics, etc. of the second port can be made uniform. 2.6 Fourth Modification of the Second Embodiment 21, 22, and 23 are also top views that schematically illustrate patches provided in the patch antenna of the fourth modified example of the second embodiment. In the patch antenna 2 of the second embodiment, the patch 12 has a square shape in a plan view as shown in Fig. 2. However, the patch 12 may have a shape other than a square. Therefore, in the patch antenna of the fourth variant of the second embodiment, for example, the patch 12 may have an octagonal shape obtained by diagonally cutting off the corners of a square shape as shown in Figure 21, or may have a shape obtained by rounding the corners of a square shape as shown in Figure 22, or may have a shape obtained by forming notches in the corners of a square shape as shown in Figure 23. 3. Third embodiment FIG. 40 is a cross-sectional view schematically illustrating the antenna module of the third embodiment. As shown in FIG. 40, the antenna module 3 of the third embodiment includes a patch antenna 101, a second dielectric layer 102, an integrated circuit chip 103, vias 104, a wiring layer 105, vias 106, and bumps 107. The patch antenna 101 is the patch antenna 1, 1a, 1b, 1c, 2, 2a, 2b, or 2c of the first embodiment or its modified example, or the second embodiment or its modified example. The integrated circuit chip 103 is disposed on the second dielectric layer 102. The integrated circuit chip 103 contains a circuit. The contained circuit sends signals to the first via 15 and the second via 16 and receives signals from the first via 15 and the second via 16. A part or all of the circuit may be replaced with a discrete circuit. The dielectric layer 11, which serves as the first dielectric layer of the patch antenna 101, is disposed on one main surface of the ground 13. The second dielectric layer 102 is disposed on the other main surface of the ground 13. The via 104, the wiring layer 105, and the via 106 are disposed in the second dielectric layer 102. The bump 107 is disposed on the second dielectric layer 102. The wiring consisting of the via 104 , the wiring layer 105 , the via 106 and the bump 107 electrically connects the first via 15 and the second via 16 to the circuit built in the integrated circuit chip 103 . The patch antenna 101, the second dielectric layer 102, the via 104, the wiring layer 105, and the via 106 constitute a monolithic antenna module substrate. The antenna module 3 may include a plurality of patch antennas 101 . The present disclosure is not limited to the above-described embodiments, and may be replaced with a configuration that is substantially the same as the configuration shown in the above-described embodiments, a configuration that has the same effect, or a configuration that can achieve the same purpose.

Claims

1. A patch antenna comprising: a dielectric layer having a first main surface and a second main surface opposite to the first main surface; a patch arranged on the first main surface; a ground arranged on the second main surface; three or more connection vias arranged in the dielectric layer and connected to the patch; a first via arranged in the dielectric layer and reaching the second main surface, the first via being electrically connected to a first two or more connection vias that are included in the three or more connection vias and arranged along a first straight line in a planar view; and a second via arranged in the dielectric layer and reaching the second main surface, the second via being electrically connected to a second two or more connection vias that are included in the three or more connection vias and arranged along a second straight line that is perpendicular to the first straight line in the planar view.

2. The patch antenna according to claim 1, wherein the patch has first two sides that are opposite and parallel to each other in the plan view and second two sides that are opposite and parallel to each other and perpendicular to the first two sides, the first straight line is parallel to the first two sides, and the second straight line is parallel to the second two sides.

3. A patch antenna as described in claim 1, comprising: a first path electrically connecting the first two or more connection vias to the first via; and a second path electrically connecting the second two or more connection vias to the second via; the dielectric layer comprises a plurality of layers stacked in the thickness direction of the dielectric layer, the plurality of layers including a first layer positioned closest to the patch and a second layer other than the first layer; and the first path and the second path are positioned between the first layer and the second layer.

4. The patch antenna according to claim 3, wherein the three or more connection vias, the first via and the second via, extend in the thickness direction of the dielectric layer, and the first path and the second path extend in the surface direction of the dielectric layer.

5. The patch antenna according to claim 1, wherein the first two or more connection vias include a first connection via and a second connection via, and the second two or more connection vias include a third connection via and a fourth connection via.

6. The patch antenna described in claim 5, wherein the first straight line and the second straight line extend in a first direction and a second direction, respectively; the first connection via, the third connection via, and the fourth connection via are arranged on one side of a first center line of the patch in the first direction in the planar view; the first connection via, the second connection via, and the third connection via are arranged on one side of a second center line of the patch in the second direction in the planar view; the second connection via is arranged on the other side of the first center line in the planar view; the fourth connection via is arranged on the other side of the second center line in the planar view; the first via is arranged on the other side of the first center line in the planar view; and the second via is arranged on the other side of the second center line in the planar view.

7. A patch antenna as described in claim 6, comprising: a first branch path branching from the first via and connected to the first connection via, the first branch path having a first length; a second branch path branching from the first via and connected to the second connection via, the second branch path having a second length longer than the first length; a third branch path branching from the second via and connected to the third connection via, the third length; and a fourth branch path branching from the second via and connected to the fourth connection via, the fourth length longer than the third length.

8. A patch antenna as described in claim 6, comprising: a first branch path branching from the first via and connected to the first connection via, the first branch path having a first length; a second branch path branching from the first via and connected to the second connection via, the second branch path having a second length shorter than the first length; a third branch path branching from the second via and connected to the third connection via, the third length; and a fourth branch path branching from the second via and connected to the fourth connection via, the fourth length shorter than the third length.

9. A patch antenna as described in claim 5, wherein the first straight line and the second straight line extend in a first direction and a second direction, respectively; the first via is arranged, in the planar view, between the first straight line and a second center line of the patch in the second direction; and the second via is arranged, in the planar view, between the second straight line and the first center line of the patch in the first direction.

10. A patch antenna according to any one of claims 5 to 9, wherein the first connection via and the third connection via are a common via.

11. A patch antenna according to any one of claims 5 to 9, wherein the first connection via and the third connection via are different vias.

12. An antenna module comprising: a patch antenna according to any one of claims 1 to 9; a circuit for sending signals to the first via and the second via, or for receiving signals from the first via and the second via; and wiring for electrically connecting the first via and the second via to the circuit.

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