JP4229418B2 - Circularly polarized patch antenna - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a circularly polarized patch antenna used for mobile communication, local area network, ITS, ETC, GPS and the like.
[0002]
[Prior art]
FIG. 8 is a perspective view showing a conventional circularly polarized patch antenna PA11.
[0003]
A conventional circularly polarized patch antenna PA11 includes a dielectric base substrate 1, a patch element 2 formed on the front surface (front surface), a GND conductor 3 provided on the back surface, and a feed conductor 4. And a power supply terminal 5 formed on the side surface thereof.
[0004]
In the conventional circularly polarized patch antenna PA11, the patch element 2 and the feed terminal 5 are capacitively coupled through a gap, and the feed terminal 5 and the feed terminal 5 are electrically connected.
[0005]
The patch element 2 has a rectangular shape as a whole, and two corner edges facing each other are chamfered. The patch antenna PA11 configured as described above can excite circularly polarized waves by adjusting the chamfering amount, and the power supply terminal 5 can be configured on the side surface. Is possible.
[0006]
FIG. 9 is a perspective view showing a conventional circularly polarized patch antenna PA12.
[0007]
A conventional circularly polarized patch antenna PA12 includes a dielectric base substrate 1, a patch element 2a formed on the front surface (front surface), and a GND conductor 3 disposed on the back surface facing the patch element 2a. And power supply pins P1 and P2, a power supply hybrid circuit 61, and a termination resistor 613.
[0008]
Here, the rectangular patch element 2a is electrically connected to the power supply pins P1 and P2, and each of the power supply pins P1 and P2 is configured on two center lines orthogonal to each other in the rectangular patch element 2a, and the power supply pins P1 and P2 Are arranged at positions where input impedances match.
[0009]
The hybrid circuit 61 includes strip lines 611 and 612, and radio waves input from the IN terminal reach the power supply pins P1 and P2 with a phase difference of 90 degrees from each other. As a result, it is possible to perform two-feed type circularly polarized wave excitation. In this way, by using the two-feeding method, it is possible to increase the bandwidth.
[0010]
FIG. 10 is a perspective view showing a conventional circularly polarized patch antenna PA13.
[0011]
A conventional circularly polarized patch antenna PA13 includes a dielectric base substrate 1, a patch element 2b formed on the surface (front surface) thereof, and a GND conductor 3 disposed on the back surface facing the patch element 2b. And power supply strip lines SLa and SLb and power supply terminals 5a and 5b.
[0012]
The conventional circularly polarized patch antenna PA13 uses a strip line as the feeding method of the patch antenna PA12, and the basic configuration method is the same as that of the patch antenna PA12. By adopting the stripline method as described above, surface mounting becomes possible.
[0013]
Japanese Patent Application Laid-Open No. 7-7321 discloses an antenna incorporating a hybrid circuit. In this conventional example, two radiating conductors are arranged so as to be orthogonal to each other, and power is supplied to each via a hybrid circuit.
[0014]
[Problems to be solved by the invention]
However, the conventional circularly polarized patch antenna PA11 has a problem that the frequency band of the axial ratio is narrow and cannot be used for applications that require a wide band.
[0015]
The conventional circularly polarized patch antenna PA12 has a problem that it cannot be surface-mounted because it is a pin-fed system, has a high mounting cost, and it is difficult to adjust impedance.
[0016]
The conventional circularly polarized patch antenna PA13 has a problem that it cannot be miniaturized because the lengths of the feeding strip lines SLa and SLb are required to some extent.
[0017]
Further, in the conventional example disclosed in JP-A-7-7321, it is necessary to arrange two elements at 90 degrees, and there is a problem that the area is large.
[0018]
An object of the present invention is to provide a circularly polarized patch antenna having a wide axial ratio frequency band, capable of surface mounting, low mounting cost, easy impedance adjustment, and small size. is there.
[0019]
[Means for Solving the Problems]
According to the present invention, a patch element is formed on the surface of the base substrate, a GND conductor is formed on the back surface of the base substrate, and two intersections between two center lines orthogonal to each other and the edge of the patch element A circularly polarized patch antenna in which a power supply conductor is capacitively coupled or resonantly coupled to a patch element and two power supply terminals that supply power to the two power supply conductors are formed on the side surface of the base substrate.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a perspective view showing a circularly polarized patch antenna PA1 according to the first embodiment of the present invention.
[0021]
The circularly polarized patch antenna PA1 includes a dielectric or magnetic base substrate 11 made of at least one of ceramic, resin, and a composite material of ceramic and resin, and a surface (front surface) of the base substrate 11. ) The rectangular patch element 21 configured in 11S1, the GND conductor 31 configured on the back surface 11S2 of the base substrate 11, the power supply conductors 41a and 41b, and the power supply terminals 51a and 51b.
[0022]
The GND conductor 31 is an excitation GND conductor for the patch element 21.
[0023]
The power supply conductors 41a and 41b are formed on the surface 11S1 of the base substrate 11 at the intersections 21Pa and 21Pb between the center lines 21La and 21Lb orthogonal to each other on the patch element 21 and the edge of the patch element 21, respectively. Capacitively coupled.
[0024]
The power supply terminals 51a and 51b are configured on the side surface 11S3 of the base substrate 11 to supply power to the power supply conductors 41a and 41b.
[0025]
The surface (front surface) 11S1 of the base substrate 11 is an example of a first surface of the base substrate, and the back surface 11S2 is an example of a second surface facing the first surface of the base substrate. 11S3 is an example of a surface different from the first and second surfaces of the base substrate.
[0026]
The patch element 21 is an example of a patch element configured on a first surface that is one surface of the base substrate. The GND conductor 31 is an example of the excitation GND conductor of the patch element formed on the second surface.
[0027]
Center lines 21La and 21Lb are examples of center lines that pass through the center point 21Pc of the patch element and are orthogonal to each other on the first surface of the base substrate. The feed conductors 41a and 41b are examples of two feed conductors that are capacitively coupled or resonantly coupled at the intersection of the two center lines and the edge of the patch element.
[0028]
The power supply terminals 51a and 51b are examples of two power supply terminals configured on a third surface that is different from the first and second surfaces of the base substrate in order to supply power to the two power supply conductors. It is.
[0029]
FIG. 2 is a diagram showing a state in which the hybrid circuit 61 is connected to the circularly polarized patch antenna PA1.
[0030]
A hybrid circuit 61 is connected to the two power supply terminals 51a and 51b in the circularly polarized patch antenna PA1.
[0031]
The hybrid circuit 61 includes strip lines 611 and 612 having a length of λ / 4, and a termination resistor 613 is connected thereto.
[0032]
By doing so, the signal input from the IN terminal is distributed to the power supply terminals 51a and 51b. In this case, the input signal reaches the power supply terminals 51a and 51b with the phase of the input signal shifted by 90 degrees. . As described above, the signals excited independently from each other are in an orthogonal resonance state on the patch element 21, and thus the circularly polarized patch antenna PA1 has a circular polarization whose frequency characteristic of the axial ratio is very wide. Exciting waves.
[0033]
FIG. 3 is a development view showing a circularly polarized patch antenna PA2 according to the second embodiment of the present invention.
[0034]
The circularly polarized patch antenna PA2 includes a circularly polarized patch antenna PA1, a base substrate 11a, and a hybrid circuit 62. The base substrate 11 a is the same substrate as the base substrate 11.
[0035]
The circularly polarized patch antenna PA1 shown in FIG. 3 is the same as the circularly polarized patch antenna PA1 shown in FIG. 1. However, for convenience of explanation, it is assumed that the GND conductor 31 is deleted. Instead of the GND conductor 31, a GND conductor 32 similar to the GND conductor 31 is provided on the base substrate 11a.
[0036]
The GND conductor 32 is provided with two cut-out portions, and power supply lands 511a and 511b are provided in the cut-out portions so as to be insulated from the GND conductor 32.
[0037]
The hybrid circuit 62 is configured on the back surface of the base substrate 11a, and a termination resistor 623 is provided in the same plane. The hybrid circuit 62 is constituted by strip lines 621 and 622 having a length of λ / 4.
[0038]
Further, the lower portions of the power supply terminals 51a and 51b in FIG. 3 are connected to power supply lands 511a and 511b, respectively, and are connected to the hybrid circuit 622 through through holes.
[0039]
Thus, since the hybrid circuit 62 is integrally accommodated in the base substrate of the circularly polarized patch antenna PA2, the overall shape can be reduced in size.
[0040]
FIG. 4 is a perspective view showing a circularly polarized patch antenna PA3 according to the third embodiment of the present invention.
[0041]
The circularly polarized patch antenna PA3 is obtained by providing feed terminals 53a and 53b using through holes in place of the feed terminals 51a and 51b provided on the side surface of the circularly polarized patch antenna PA1.
[0042]
When a plurality of circularly polarized patch antennas PA3 are manufactured at the same time, a plurality of base substrates 13 are manufactured by dividing a base substrate having a size corresponding to a plurality of the base substrates 13. The position of the through hole is set so that half of the through hole is located on the side surface 13S3. Then, when the base substrate 13 is divided, the through hole is cut in about half, thereby forming recesses Ca and Cb, and feeding terminals 53a and 53b are formed in the recesses Ca and Cb, respectively.
[0043]
The base substrate 13, the front surface (front surface) 13S1, the back surface 13S2, the side surface 13S3, the patch element 23, the center point 23Pc, the center lines 23La and 23Lb, the intersection points 23Pa and 23Pb, the GND conductor 33, the power supply conductors 43a and 43b, The feed terminals 53a and 53b are respectively the base substrate 11 of the circularly polarized patch antenna PA1, the front surface (front surface) 11S1, the back surface 11S2, the side surface 11S3, the patch element 21, the center point 21Pc, the center lines 21La and 21Lb, and the intersections. This corresponds to 21Pa, 21Pb, the GND conductor 31, the feeding conductors 41a and 41b, and the feeding terminals 51a and 51b.
[0044]
FIG. 5 is a perspective view showing a circularly polarized patch antenna PA4 according to the fourth embodiment of the present invention.
[0045]
FIG. 6 is a development view showing the circularly polarized patch antenna PA4.
[0046]
The circularly polarized patch antenna PA4 is an embodiment in which a hybrid circuit 64 is provided inside a base substrate 14, 141, 142, 143 similar to the base substrate 11 of the circularly polarized patch antenna PA1. It consists of strip lines. That is, the hybrid circuit 64 is a circuit configured as a strip line between the excitation GND conductor 34 of the patch element and the second GND conductor 341.
[0047]
The circularly polarized patch antenna PA4 includes the base substrates 14, 141, 142, and 143, the rectangular patch element 21 formed on the upper surface of the base substrate 14 in FIG. 6, and the upper surface of the base substrate 141 in FIG. The configured patch element excitation GND conductor 34, the GND conductor 341 formed on the upper surface of the base substrate 143 in FIG. 6, the power supply conductors 43a and 43b, the power supply terminals 53a and 53b, and the hybrid circuit 64 It is constituted by.
[0048]
The feed conductors 43 a and 43 b are capacitively coupled to the patch element 21 on the upper surface of the base substrate 14 at the intersections between the two center lines orthogonal to each other on the patch element 21 and the edge of the patch element 21. ing.
[0049]
The power supply terminals 53a and 53b are configured on the side surfaces of the base substrates 14, 141, 142, and 143 to supply power to the power supply conductors 43a and 43b.
[0050]
Further, each of the four corner portions is provided with a 1/4 through hole (a through hole divided by 1/4 by dicing or the like) 33c. The 1/4 through hole is connected to the GND conductors 34 and 341, Is for connecting.
[0051]
The hybrid circuit 64 is formed by strip lines 641 and 642 provided on the upper surface of the base substrate 142 in FIG. 6 and having a length of λ / 4.
[0052]
When the circularly polarized patch antenna PA4 is manufactured, the base substrates 143, 142, 141, and 14 are stacked in this order and integrated by pressing or the like, so that the circularly polarized patch antenna PA4 with a built-in hybrid circuit shown in FIG. Is formed.
[0053]
FIG. 7 is a diagram showing frequency characteristics of the circularly polarized patch antenna PA11 which is the conventional example and the circularly polarized patch antennas PA1 and PA2 which are the above-described embodiments.
[0054]
FIG. 7A is a diagram illustrating the frequency characteristic of VSWR, which is a reflection characteristic. In FIG. 7A, a characteristic 8a indicated by a two-dot chain line is a VSWR characteristic of the conventional circularly polarized patch antenna PA11. A characteristic 81 indicated by an alternate long and short dash line is a VSWR characteristic of the circularly polarized patch antenna PA1 of the embodiment. A characteristic 82 indicated by a broken line is a reflection characteristic that is a VSWR characteristic of the circularly polarized patch antenna PA2 in which the hybrid circuit 62 is built in the base substrate.
[0055]
When the reflection characteristic is seen from the input part of the hybrid circuit with the antenna connected, it becomes a broken line characteristic 82. Therefore, the hybrid-integrated circularly polarized patch antenna PA2 has a very wide band as shown by the broken line characteristic 82. Although it becomes a reflection characteristic, the reflection characteristic with respect to radiation loss is equivalent to the characteristic 81 of a dashed-dotted line.
[0056]
FIG. 7B is a diagram illustrating the frequency characteristics of the axial ratio. In FIG. 7 (2), a characteristic 9a indicated by a two-dot chain line is an axial ratio characteristic of the conventional circularly polarized patch antenna PA11. A characteristic 92 indicated by a broken line is an axial ratio characteristic of the circularly polarized patch antenna PA2 in which the hybrid circuit 62 is built in the base substrate.
[0057]
As described above, the circularly polarized patch antenna according to the above-described embodiment configured by two-feed capacitive coupling can have a wide band.
[0058]
In the above-described embodiment, impedance adjustment and pattern adjustment are easy.
[0059]
Furthermore, conductors such as patch element 21, GND conductors 31, 32, 34, 341, power supply terminals 51a, 51b, 53a, 53b, strip lines 61, 64 are gold, silver, copper, palladium, platinum, silver palladium, silver, and the like. A conductor such as platinum or aluminum is formed by printing, plating, vapor deposition, sputtering, etching, or the like.
[0060]
The GND conductors 31, 32, and 34 are examples of the patch element excitation GND conductor formed on the second surface of the base substrate facing the first surface, and are opposed to the first surface. In addition, an excitation GND conductor of the patch element may be formed on a surface existing in the base substrate.
[0061]
The feed conductors 41a, 41b, 43a, 43b are capacitively coupled or resonantly coupled at the intersections of two centerlines that pass through the center point of the patch element and are orthogonal to each other on the patch element, and the edge of the patch element. This is an example of two power supply conductors, and the power supply conductors 41a and 41b may be provided on the side surface of the base substrate.
[0062]
Each of the above embodiments is a circularly polarized patch antenna that can be used for mobile communication, a local area network, ITS (Intelligent Transport System), ETC (Electronic Toll Collection System), GPS, and the like.
[0063]
【The invention's effect】
The circularly polarized patch antenna of the present invention has an effect that the frequency band of the axial ratio is wide, surface mounting is possible, mounting cost is low, impedance adjustment is easy, and the size is small.
[Brief description of the drawings]
FIG. 1 is a perspective view of a circularly polarized patch antenna PA1 according to a first embodiment of the present invention.
FIG. 2 is a diagram showing a state in which a hybrid circuit 61 is connected to a circularly polarized patch antenna PA1.
FIG. 3 is a development view of a circularly polarized patch antenna PA2 according to a second embodiment of the present invention.
FIG. 4 is a perspective view of a circularly polarized patch antenna PA3 that is a third embodiment of the present invention.
FIG. 5 is a perspective view of a circularly polarized patch antenna PA4 according to a fourth embodiment of the present invention.
FIG. 6 is a development view showing a circularly polarized patch antenna PA4.
FIG. 7 is a diagram illustrating frequency characteristics of a circularly polarized patch antenna PA11 that is a conventional example and the circularly polarized patch antennas PA1 and PA2 that are the above examples.
FIG. 8 is a perspective view showing a conventional circularly polarized patch antenna PA11.
FIG. 9 is a perspective view showing a conventional circularly polarized patch antenna PA12.
FIG. 10 is a perspective view showing a conventional circularly polarized patch antenna PA13.
[Explanation of symbols]
PA1, PA2, PA3, PA4 ... Circularly polarized patch antennas,
11, 11a, 13, 14, 141, 142, 143 ... base substrate,
11S1 ... the surface (front surface) of the base substrate,
11S2 ... the back surface of the base substrate,
11S3: side surface of the base substrate,
21 ... Patch element,
21Pc ... center,
21 Pa, 21 Pb ... intersection,
21La, 21Lb ... center line,
31, 32, 34 ... GND conductors for exciting patch elements,
341 ... GND conductor,
41a, 41b, 43a, 43b ... feeding conductor,
51a, 51b, 53a, 53b ... power supply terminal,
61, 64 ... hybrid circuit,
611, 612, 641, 642 ... stripline.

Claims (4)

A dielectric or magnetic base substrate made of at least one of ceramic, resin, and a composite material of ceramic and resin;
A patch element formed on a first surface which is one surface of the base substrate;
An excitation GND conductor of a patch element configured on a second surface of the base substrate facing the first surface, or a surface in the base substrate facing the first surface;
Two feed conductors that are capacitively coupled or resonantly coupled at the intersections of two centerlines that pass through the center point of the patch element and are orthogonal to each other on the patch element; and
Two power supply terminals configured on a third surface of the base substrate different from the first and second surfaces to supply power to each of the two power supply conductors;
A circularly polarized patch antenna comprising: In claim 1,
A circularly polarized patch antenna, wherein a hybrid circuit that shifts the phase of a signal input from an IN terminal by 90 degrees is integrated with the circularly polarized patch antenna. In claim 2,
The circularly polarized patch antenna, wherein the hybrid circuit is laminated with the base substrate. In claim 3,
When viewed from the excitation for the GND conductor of the patch element, and the patch element is provided on the opposite side, a second GND conductor is fixed to the base substrate,
The circularly polarized patch antenna, wherein the hybrid circuit is a circuit configured as a strip line between a GND conductor for exciting the patch element and the second GND conductor.

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