JP2014082623A - Patch antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a patch antenna capable of accurately and easily adjusting a degeneration separation frequency and a resonance frequency without directly adjusting the pattern shape of a radiation electrode.SOLUTION: A patch antenna 10 includes a dielectric block 11, a radiation electrode 12 formed on a top surface 11a of the dielectric block 11, a power-feeding electrode 13 formed on a bottom surface 11b of the dielectric block 11, an electrode 14 for frequency adjustment, an electrode 15 for degeneration adjustment, and a ground electrode 16. The electrode 14 for frequency adjustment is provided so as to straddle from a first corner cb1 to a third corner cb3 of the bottom surface 11b of the dielectric block 11. The electrode 15 for degeneration adjustment is provided at a second corner cb2 or a fourth corner cb4. At the first corner cb1, an element 31 for frequency adjustment is connected to the electrode 14 for frequency adjustment, and an element 32 for degeneration adjustment is connected to the electrode 15 for degeneration adjustment.

Description

  The present invention relates to a patch antenna, and more particularly to an electrode structure of a surface mount type patch antenna.

  In recent years, the GPS function has been installed in various electronic devices such as a mobile phone, a smartphone, a digital camera, and a digital video camera as standard. In order to receive a GPS signal, a GPS antenna is required, and a patch antenna is preferably used as the GPS antenna.

  The patch antenna for GPS is a kind of microstrip antenna, and it has been optimized to receive GPS signals with high sensitivity. However, due to the influence of the mounting position on the printed circuit board and surrounding mounting parts, There are cases where GPS signals cannot be received with high sensitivity. In this case, it is necessary to change the pattern shape of the radiation electrode and the value of the characteristic adjustment element. Patent Documents 1 and 2 disclose a patch antenna that can easily perform such characteristic adjustment.

JP 2001-230623 A Japanese Patent No. 4507385

  However, since the conventional patch antenna described above can only adjust two resonance frequencies constituting the circularly polarized wave individually, it is accompanied by a change in polarization mode and a change in resonance frequency simultaneously with a change in degenerate separation frequency, There is a problem that fine adjustment of the degenerate separation frequency and the resonance frequency is very difficult.

  The present invention has been made to solve the above problems, and the object of the present invention is to form the shape of an electrode pattern such as a radiating electrode even when the characteristics have to be adjusted according to the mounting environment. An object of the present invention is to provide a patch antenna that can adjust the degenerate separation frequency and the resonance frequency with high accuracy and easily by simply changing the value of the characteristic adjustment element without directly adjusting.

  In order to solve the above-described problems, a patch antenna according to the present invention includes a dielectric block, a radiation electrode formed on the top surface of the dielectric block, a feeding electrode formed on the bottom surface of the dielectric block, and a frequency adjusting electrode. , A degeneration adjustment electrode and a ground electrode, wherein the bottom surface of the dielectric block has first and second sides parallel to each other, and third orthogonal to the first and second sides and parallel to each other. And a fourth edge, a first corner located at the intersection of the first edge and the third edge, and a second edge located at the intersection of the first edge and the fourth edge. , A third corner located at the intersection of the second side and the third side, and a fourth corner located at the intersection of the second side and the fourth side And the frequency adjusting electrode includes the first corner of the bottom surface of the dielectric block and the first So as to cover the corners, the provided along the first side, the degenerate adjustment electrode is characterized in that provided in the fourth corner or the second corner.

  According to the present invention, the degenerate separation frequency can be adjusted without changing the resonance frequency by changing the reactance of the frequency adjusting electrode. Further, by changing the reactance of the degeneration adjustment electrode, the degeneracy separation amount can be adjusted without largely changing the degeneration separation frequency. Therefore, the antenna gain of the patch antenna can be controlled with high accuracy.

  The patch antenna according to the present invention further includes a frequency adjustment element connected to the frequency adjustment electrode, and a degeneration adjustment element connected to the degeneration adjustment electrode, and the frequency adjustment electrode includes the frequency adjustment element. Preferably, the degeneration adjustment electrode is connected to the ground via the degeneration adjustment element, and is connected to the ground via the degeneration adjustment element. According to this configuration, it is possible to finely adjust the degenerate separation frequency and the degenerate separation amount without greatly changing the resonance frequency, and thereby the antenna gain can be adjusted with high accuracy.

  The patch antenna according to the present invention includes a notch provided at a corner of the radiation electrode located above at least one of the first corner and the fourth corner of the bottom surface of the dielectric block. It is preferable to further include a degenerate separation element. According to this configuration, the resonance mode adjusted by the degenerative separation element can be adjusted also by the frequency adjustment electrode and the degeneration adjustment electrode, and the degenerative separation frequency and the degenerative separation amount can be adjusted with high accuracy. It becomes.

  In the present invention, it is preferable that the power supply electrode is provided in contact with the third side of the bottom surface of the dielectric block. According to this configuration, it is possible to configure a right-handed circularly polarized wave antenna that allows easy adjustment of the degenerate separation frequency and degenerate separation amount.

  According to the present invention, a dielectric block such as a radiation electrode can be used even when the characteristics of the patch antenna are to be finely adjusted due to the position of the printed circuit board on which the patch antenna is mounted or the influence of electronic components mounted on the periphery. By changing the values of reactive elements such as inductors and capacitors without directly adjusting the shape of the electrode pattern on the surface, it is possible to adjust the degenerate separation frequency and the degenerate separation amount. In particular, it is possible to adjust only the degenerate separation frequency without changing the degenerate separation amount, and it is easy to finely adjust the characteristics. Therefore, adjustment by the user himself becomes possible, and the antenna gain of the patch antenna can be controlled with high accuracy.

1 is a schematic perspective view showing a configuration of a patch antenna according to a first embodiment of the present invention. It is a top view of the patch antenna shown in FIG. It is a graph which shows the VSWR characteristic when the element value of the element for a frequency adjustment of the patch antenna shown in FIG. 1 is changed. It is a Smith chart which shows an impedance characteristic when the element value of the element for a frequency adjustment of the patch antenna shown in FIG. 1 is changed. It is a graph which shows the change of the degeneracy separation frequency when the element value of the element for a frequency adjustment of the patch antenna shown in FIG. 1 is changed. It is a Smith chart which shows an impedance characteristic when the element value of the degeneration adjustment element of the patch antenna shown in FIG. 1 is changed.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a schematic perspective view showing a configuration of a patch antenna according to a first embodiment of the present invention, and shows a state separated from a printed circuit board. FIG. 2 is a plan view of the patch antenna shown in FIG.

  As shown in FIGS. 1 and 2, the patch antenna 10 includes a dielectric block 11, a radiation electrode 12 formed on the upper surface 11 a of the dielectric block 11, and a feeding electrode formed on the bottom surface 11 b of the dielectric block 11. 13, a frequency adjustment electrode 14, a degeneration adjustment electrode 15, and a ground electrode 16.

  The outer shape of the dielectric block 11 is a substantially rectangular parallelepiped, and has an upper surface 11a, a bottom surface 11b, and four side surfaces 11c to 11f. Furthermore, chamfering is applied to the corners of each side surface to prevent chipping of the block. In the present embodiment, the shape of the upper surface 11a and the bottom surface 11b of the dielectric block 11 is preferably a square or a rectangle close thereto. Specifically, the outer dimension of the dielectric block can be set to 12 × 12 × 4 (mm).

  The upper surface 11a of the dielectric block 11 includes first and second sides ea1 and ea2 that are parallel to each other, and third and fourth sides ea3 that are orthogonal to the first and second sides ea1 and ea2 and are parallel to each other. It has ea4. The first corner ca1 located at the intersection of the first side ea1 and the third side ea3 and the second corner ca2 located at the intersection of the first side ea1 and the fourth side ea4. A third corner ca3 located at the intersection of the second side ea2 and the third side ea3, and a fourth corner ca4 located at the intersection of the second side ea2 and the fourth side ea4. And have.

  Similarly to the top surface 11a, the bottom surface 11b of the dielectric block 11 also includes first and second sides eb1 and eb2 that are parallel to each other, and third surfaces that are orthogonal to and parallel to the first and second sides eb1 and eb2. And fourth sides eb3 and eb4. The first corner cb1 located at the intersection of the first side eb1 and the third side eb3, and the second corner cb2 located at the intersection of the first side eb1 and the fourth side eb4. A third corner cb3 located at the intersection of the second side eb2 and the third side eb3, and a fourth corner cb4 located at the intersection of the second side eb2 and the fourth side eb4 And have.

  The material of the dielectric block 11 is not particularly limited, but a Ba—Nd—Ti-based material (relative permittivity of 80 to 120), Nd—Al—Ca—Ti based material (relative permittivity of 43 to 46). ), Li—Al—Sr—Ti (relative permittivity 38 to 41), Ba—Ti based material (relative permittivity 34 to 36), Ba—Mg—W based material (relative permittivity 20 to 22), Mg— Use Ca-Ti-based materials (relative permittivity 19-21), sapphire (relative permittivity 9-10), alumina ceramics (relative permittivity 9-10), cordierite ceramics (relative permittivity 4-6), etc. It can be made by firing using a mold.

  A radiation electrode 12 is provided on the upper surface 11 a of the dielectric block 11. The shape of the radiation electrode 12 is a substantially square having a side of about λ / 2, and the first to fourth sides ea1 to ea4 of the upper surface 11a of the dielectric block 11 (and the first to fourth sides eb1 to eb1 of the bottom surface 11b). It has four sides parallel to eb4). Moreover, it has four corners in the same direction as the first to fourth corners ca1 to ca4 of the upper surface 11a (and the first to fourth corners cb1 to cb4 of the bottom surface 11b). The shape and area of the radiation electrode 12 are generally determined by the relationship with the operating frequency. Here, as shown in the figure, the rectangular radiation electrode 12 is formed with a certain margin inside the outer periphery of the upper surface 11a of the dielectric block 11. The

  As shown in FIG. 2, the two corners of the radiation electrode 12 in the same direction as the first and fourth corners ca1 and ca4 of the dielectric block 11 are notched as degenerate separation elements 17A and 17B. Is provided. When the position of the power supply electrode 13 (power supply point) is directed downward as shown in the figure, the degenerate separation element 17A is formed by cutting out the lower left corner of the radiation electrode 12, and the degeneration separation element 17B is a radiation electrode. 12 is formed by cutting out the upper right corner of 12.

  By these two degenerate separation elements 17A and 17B, the phase shifts toward the higher resonance mode frequency in the arrow B direction compared to the resonance mode frequency in the arrow A direction. Since the phase advances almost in proportion to the area of the degenerate separation elements 17A and 17B, the resonance mode in the direction of arrow B is compared with the resonance mode in the direction of arrow A by forming the degeneration separation elements 17A and 17B having appropriate sizes. The phase advances 90 degrees. Moreover, since each intensity | strength is the same, the counterclockwise resonance mode generate | occur | produces toward a figure. As a result, it operates as a right-handed circularly polarized antenna in which the electric field component of the radiated electromagnetic field rotates rightward in a plane perpendicular to the propagation direction in the used frequency band. Here, the used frequency band is a band having the resonance frequency of the radiation electrode 12 as a center frequency, and the frequency band in which the length of one side of the radiation electrode 12 is about half (λ / 2) of the propagation wavelength in the dielectric block 11. It is.

  A power supply electrode 13, a frequency adjustment electrode 14, a degeneration adjustment electrode 15, and a ground electrode 16 are provided on the bottom surface 11 b of the dielectric block 11. These electrodes 13 to 16 are capacitively coupled to the radiation electrode 12. There are no electrode patterns on the four side surfaces 11c to 11f of the dielectric block 11, and the base of the dielectric block 11 is completely exposed.

  The power supply electrode 13 is a small rectangular electrode pattern provided at a position in contact with the first side eb1 of the bottom surface 11b of the dielectric block 11. The power supply electrode 13 is connected to a power supply pad 23 on the printed circuit board 20. The power supply electrode 13 according to the present embodiment is disposed at the center of the first side eb1.

  The frequency adjusting electrode 14 is an elongated belt-like electrode pattern provided so as to extend from the first corner portion cb1 to the third corner portion cb3 of the bottom surface 11b of the dielectric block 11. The frequency adjusting electrode 14 is connected to the ground pattern 21 on the printed circuit board 20 via the frequency adjusting land 24 and the frequency adjusting element 31 on the printed circuit board 20 provided at the first corner cb1.

  The degeneration adjustment electrode 15 is a small rectangular electrode pattern provided on a fourth corner cb4 that is diagonally related to the first corner cb1 of the bottom surface 11b of the dielectric block 11. The degeneration adjustment electrode 15 is connected to the ground pattern 21 on the printed circuit board 20 via a degeneration adjustment land 25 and a degeneration adjustment element 32 on the printed circuit board 20 provided at the fourth corner cb4.

  The ground electrode 16 is an electrode pattern provided in most of the region of the bottom surface 11 b of the dielectric block 11 other than the region where the power supply electrode 13, the frequency adjustment electrode 14, and the degeneration adjustment electrode 15 are formed. An insulating space having a predetermined width is interposed between the ground electrode 16 and the other electrode patterns 13 to 15, and insulation with the other electrode patterns 13 to 5 is ensured.

  These electrode patterns 12 to 16 are formed by applying an electrode paste material on the surface of the dielectric block 11 by a method such as screen printing or transfer and then baking it at a predetermined temperature condition. Silver, silver-palladium, silver-platinum, copper, or the like can be used as the electrode paste material.

  Land patterns having substantially the same shape as the electrode patterns 13 to 15 on the bottom surface 11 b of the patch antenna 10 are formed in the mounting area of the patch antenna 10 on the printed circuit board 20. That is, in the antenna mounting region, a power supply pad 23 connected to the power supply electrode 13, a frequency adjustment land 24 connected to the frequency adjustment electrode 14, and a degeneration adjustment land 25 connected to the degeneration adjustment electrode 15. A ground pattern 26 connected to the ground electrode 16 is formed. Further, a ground pattern 21 is formed around the antenna mounting area. Although the ground pattern 21 is an integrated pattern with the ground pattern 26, it is shown as a separate pattern for convenience of explanation. The ground pattern 21 does not have to completely surround the antenna mounting area, and may partially surround the antenna mounting area.

  The power supply pad 23 is connected to the power supply line 22. Two impedance adjusting elements 33 and 34 are connected to the power supply line 22 near the power supply pad 23. One impedance adjustment element 33 is inserted in series with respect to the power supply line 22, and the other impedance adjustment element 34 is inserted in parallel with respect to the power supply line 22. The impedance adjustment elements 33 and 34 are reactive elements made of a chip inductor or a chip capacitor, and the input impedance of the patch antenna 10 can be adjusted by changing the element value.

  As described above, the resonance length of the resonance mode in the direction of the diagonal line A in which the two degenerate separation elements 17A and 17B exist is shorter than the resonance length of the resonance mode in the direction of the other diagonal line B orthogonal thereto. By setting so that the phase difference between the non-degenerate resonance mode and the degenerated resonance mode is about 90 degrees, the main mode combining both resonance modes is excited, and the patch antenna 10 is moved to the right. It can be operated as a circularly polarized antenna.

  One end of the frequency adjustment electrode 14 extending along the third side eb3 of the bottom surface 11b of the dielectric block 11 is located at the first corner cb1 involved in one resonance mode, and the other end is It is located at the second corner cb3 involved in the other resonance mode. That is, the frequency adjustment electrode 14 is provided so as to cover both the first corner portion cb1 and the third corner portion cb3. Therefore, the two resonance modes can be moved simultaneously by changing the reactance of the frequency adjusting electrode 14.

  A frequency adjusting element 31 is inserted in series between the frequency adjusting electrode 14 and the surrounding ground pattern 21 in the first corner portion cb1. The frequency adjusting element 31 is a reactive element composed of a chip inductor or a chip capacitor, and the degenerate separation frequency of the patch antenna 10 can be adjusted by changing the element value. That is, the frequency adjusting electrode 14 is an elongated electrode pattern extending from the first corner portion cb1 to the third corner portion cb3 along the third side eb3 of the bottom surface 11b of the dielectric block 11. When the value of the frequency adjustment element 31 connected to is changed, both the non-degenerate resonance mode indicated by the arrow A and the degenerate resonance mode indicated by the arrow B in FIG. . That is, the degenerate separation frequency can be shifted.

  A degeneration adjustment element 32 is inserted in series between the degeneration adjustment electrode 15 and the surrounding ground pattern 21 in the fourth corner portion cb4. The degeneration adjustment element 32 is a reactive element composed of a chip inductor or a chip capacitor, and the degeneration separation amount of the patch antenna 10 can be adjusted by changing the element value. That is, the degeneration adjustment electrode 15 is an electrode pattern formed on the fourth corner cb4 of the bottom surface 11b of the dielectric block 11, and when the value of the degeneration adjustment element 32 connected thereto is changed. 2, only the degenerated resonance mode indicated by the arrow B can be moved without moving the non-degenerate resonance mode indicated by the arrow A in FIG. 2. That is, the degenerate separation amount can be adjusted.

  When the patch antenna 10 is mounted on the printed circuit board 20, each electrode pattern on the bottom surface 11 b side of the dielectric block 11 is soldered to a corresponding land on the printed circuit board 20. The solder connection is performed by, for example, a reflow process. Thus, the radiation electrode 12 is connected to the power supply line 22 on the printed circuit board 20 through capacitive coupling with the power supply pad 23, and is connected to the RF circuit (not shown) through the power supply line 22. Further, the frequency adjusting electrode 14 is grounded via the frequency adjusting element 31, and the degeneration adjusting electrode 15 is grounded via the degeneration adjusting element 32.

  FIG. 3 is a graph showing the VSWR characteristics when the element value of the frequency adjusting element 31 of the patch antenna 10 shown in FIG. 1 is changed. The horizontal axis indicates the frequency (GHz), and the vertical axis indicates the VSWR. ing. FIG. 4 is a Smith chart showing impedance characteristics when the element value of the frequency adjusting element 31 of the patch antenna 10 shown in FIG. 1 is changed. FIG. 5 is a Smith chart showing the patch antenna 10 shown in FIG. It is a graph which shows the change of the degeneracy separation frequency when the element value of the element 31 for frequency adjustment is changed. Note that a capacitor is used for the frequency adjusting element 31 and its value (measurement parameter) is 0 nF (short), 1 nF, 1.5 nF, 2 nF, 3 nF, 4 nF, 5 nF, 6 nF, 7 nF, 8 nF, 10 nF, ∞ (open). It is what.

  As apparent from FIGS. 3 to 5, when the value of the frequency adjustment element 31 is changed, the bottom peak (resonance frequency) of the VSWR hardly changes, but the degenerate separation frequency is 1.582 to 1.598 GHz. It varies in the range. In FIG. 3, the resonance frequency tends to shift slightly toward the high frequency side as the capacitance of the frequency adjusting element 31 increases. Also on the Smith chart of FIG. 4, it can be seen that the position of the dent of the loop, that is, the degenerate separation frequency is shifted in accordance with the increase in capacitance. Thus, the degenerate separation frequency can be adjusted by changing the value of the frequency adjustment element 31.

  As described above, in this embodiment, by changing the element value of the frequency adjustment element 31, the degenerate separation frequency can be adjusted without greatly changing the resonance frequency. The degenerate separation frequency can increase the antenna gain by making this degenerate separation frequency as close as possible to the carrier frequency (1.575 GHz) of the GPS signal. Here, the degenerate separation frequency is a frequency at which the reception sensitivity of circularly polarized waves is the strongest, and appears on the Smith chart as a position of a small loop or a position of a loop in the middle of the impedance locus. By changing the element value of the frequency adjusting element 31, the position of the small loop or the position of the recess in the loop can be changed without largely changing the shape of the loop or the size of the recess.

  FIG. 6 is a Smith chart showing impedance characteristics when the element value of the degeneration adjustment element 32 of the patch antenna 10 shown in FIG. 1 is changed. Note that a capacitor is used for the degeneracy adjusting element 32, and its value (measurement parameter) is set to four types of 1 pF, 3 pF, 6 pF, and 10 pF.

  As is apparent from FIG. 6, when the value of the degeneration adjustment element 32 is changed, the size of the small loop of the impedance locus constituting the double loop changes. In particular, when the capacitor is 1 pF, almost no small loop occurs, and the size of the small loop increases as the capacitance increases. Thus, by changing the value of the degeneration adjustment element 32, the size of the small loop on the Smith chart, that is, the degeneracy separation amount can be adjusted.

  As described above, in the present embodiment, by changing the element value of the degeneration adjustment element 32, the degeneracy separation amount can be adjusted without greatly changing the degeneration separation frequency. The degenerate separation amount appears on the Smith chart as the size of a small loop or the size of a recess in the middle of the impedance locus. By changing the element value of the degeneration adjustment element 32, the size of the small loop or the size of the dent can be changed without largely changing the shape of the loop or the position of the dent of the loop.

  As described above, the patch antenna according to the present embodiment includes the frequency adjustment electrode 14 and the degeneration adjustment electrode 15 provided on the bottom surface 11b of the dielectric block 11, and the value of the reactive element connected to each of them. By individually adjusting the defocus separation frequency, the degenerate separation frequency and the degenerate separation amount can be controlled independently. Therefore, it is possible to provide a patch antenna that allows easy adjustment of the antenna gain.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention. Needless to say, it is included in the range.

  For example, in the above embodiment, the degeneration adjustment electrode 15 is provided in the fourth corner cb4. However, the present invention is not limited to such a configuration, and the degeneration adjustment electrode 15 is not provided in the first corner cb4. You may provide in corner | angular part cb1. In this case, the frequency adjusting electrode 14 may be provided on the fourth side eb4. Further, the degeneration adjustment electrode 15 may be provided on the first corner cb1, and the frequency adjustment electrode 14 may be provided on the first side eb1.

  In the above embodiment, the power supply electrode 13 is provided at a position in contact with the first side eb1 of the bottom surface 11b of the dielectric block 11, but the position at which the power supply electrode 13 is in contact with the second side eb2 or the fourth side You may provide in the position which contacted eb4.

  Further, in the above embodiment, the notches are provided in the two corners having the diagonal relationship of the radiation electrode, but the notches may be provided only in one of the corners, and the notches are not provided at all. It doesn't matter.

  Further, in the above embodiment, the frequency adjustment element 31 and the degeneration adjustment element 32 are mounted on one main surface of the same printed circuit board as the mounting surface of the patch antenna 10, but are mounted on the other main surface. Alternatively, it may be connected to the frequency adjusting electrode 14 or the degeneration adjusting electrode 15 through a through-hole conductor.

  In the above embodiment, the structure of the right-handed circularly polarized antenna is described. However, the present invention is not limited to the application to the right-handed circularly polarized antenna, and can be applied to the left-handed circularly polarized antenna. It is. Further, the patch antenna according to the present invention is not limited to the GPS, and can be applied to various other uses.

DESCRIPTION OF SYMBOLS 10 Patch antenna 11 Dielectric block 11a Dielectric block upper surface 11b Dielectric block bottom surface 11c-11f Dielectric block side surface 12 Radiation electrode 13 Feeding electrode 14 Frequency adjustment electrode 15 Degeneration adjustment electrode 16 Ground electrodes 17A and 17B Degeneration Separation element 20 Printed circuit board 21 Ground pattern 22 Feed line 23 Feed pad 24 Frequency adjustment land 25 Degeneration adjustment land 26 Ground pattern 31 Frequency adjustment element 32 Degeneration adjustment element 33 Impedance adjustment element 34 Impedance adjustment elements ca1 to ca4 Dielectric Corners cb1 to cb4 on the top surface of the block Corners ea1 to ea4 on the bottom surface of the dielectric block Sides eb1 to eb4 on the top surface of the dielectric block Sides on the bottom surface of the dielectric block

Claims (4)

A dielectric block;
A radiation electrode formed on an upper surface of the dielectric block;
A power supply electrode, a frequency adjustment electrode, a degeneration adjustment electrode and a ground electrode formed on the bottom surface of the dielectric block;
The bottom surface of the dielectric block is
First and second sides parallel to each other;
Third and fourth sides orthogonal to and parallel to the first and second sides;
A first corner located at the intersection of the first side and the third side;
A second corner located at the intersection of the first side and the fourth side;
A third corner located at the intersection of the second side and the third side;
A fourth corner located at the intersection of the second side and the fourth side;
The frequency adjusting electrode is provided along the first side so as to cover the first corner and the third corner of the bottom surface of the dielectric block,
The patch antenna, wherein the degeneration adjustment electrode is provided at the fourth corner or the second corner. A frequency adjusting element connected to the frequency adjusting electrode;
A degeneration adjustment element connected to the degeneration adjustment electrode;
The frequency adjusting electrode is connected to the ground through the frequency adjusting element,
The patch antenna according to claim 1, wherein the degeneration adjustment electrode is connected to a ground via the degeneration adjustment element.   A degenerate separation element comprising a notch provided at a corner of the radiation electrode located above at least one of the first corner and the fourth corner of the bottom surface of the dielectric block; The patch antenna according to claim 1 or 2.   4. The patch antenna according to claim 1, wherein the feeding electrode is provided in contact with the third side of the bottom surface of the dielectric block. 5.