JP2002190707A - Plane antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly versatile plane antenna in which the direction of a main beam is easily changed. SOLUTION: Many patch units 5 in the same shapes are constituted of patch electrodes 9 formed on the surface of a circular dielectric substrate 8, power feeding pins 10 soldered to the power feeding points of the patch electrodes 9. The power feeding pins 10 extend downward through the center of the dielectric substrates 8. A ground plate 3 having many through holes 3a and a guide plate 4 having many guide holes 4a are jointed and integrated so that the centers of the through holes 3a and the guide holes 4a are matched. Thus, an antenna base 7 is obtained. The patch units 5 are inserted into the guide holes 4a of the antenna base 7 respectively and the power feeding pins 10 are inserted into the through holes 3a respectively. The patch units 5 are rotated on the ground plate 3 with the power feeding pins 10 as the center. Thus, the patch units 5 are installed at optimum angles in accordance with the requested direction of the main beam.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a planar antenna used as a tracking type or a fixed type, and more particularly to a patch array type planar antenna in which a number of patch electrodes are arranged.

[0002]

2. Description of the Related Art FIGS. 7A and 7B illustrate a conventional example of such a patch array type planar antenna. FIG. 7A is a plan view and FIG. 7B is a sectional view. However, FIG.
(A) and (b) schematically show the basic configuration, in which the number and shape of the patch electrodes are drawn in a simplified manner.

A conventional planar antenna 20 shown in FIG. 7 includes a dielectric substrate 21 made of a dielectric material having a small relative dielectric constant such as polytetrafluoroethylene (trade name: Teflon) and a dielectric substrate 21 formed on the surface of the dielectric substrate 21. A plurality of patch electrodes 22, a ground electrode 23 formed on the entire back surface of the dielectric substrate 21, and a feed pin 24 extending downward from the feed point of each patch electrode 22 through the dielectric substrate 21. Each of the patch electrodes 22 and the ground electrode 23 is patterned into a desired shape by etching a copper foil provided on both surfaces of the dielectric substrate 21. This planar antenna 20 is fixed to a radial waveguide 25, and each feed pin 24 is inserted into the radial waveguide 25. A probe 26 is attached to the center of the bottom surface of the radial waveguide 25, and the probe 26 is connected to an LNB (not shown) via a coaxial cable 27.

FIG. 8A is a plan view showing one of the patch electrodes 22 in detail, and FIG. 8B is a cross-sectional view taken along the line AA in FIG. The external shape of the patch electrode 22 is circular, and a power supply pin 24 is soldered to a power supply point remote from the center point. A pair of cutouts 22 a are formed on the outer peripheral edge of the patch electrode 22, and the cutouts 22 a face each other on a straight line passing through the center point of the patch electrode 22. These notches 22a are called degenerate separation elements, and have the function of separating the orthogonal modes that resonate, and the frequencies for the two resonance modes change to different frequencies. At that time, at a frequency substantially intermediate between these two frequencies, a 90 ° phase difference is generated in the excitation phase, and a circularly polarized wave is generated. As described above, a large number of such patch electrodes 22 are arranged on the surface of the dielectric substrate 21. In this case, a plurality of concentric circles are set on the dielectric substrate 21 and each concentric circle is set on the circumference of these concentric circles. The patch electrodes 22 are arranged so as to be arranged at equal intervals. However, the installation direction of each patch electrode 22
(The direction of the notch 22a) is set to an optimal angle according to the direction of the satellite to be received.
The principle of beam tilt in which the direction of the radiation beam is inclined according to the installation direction of 2 will be described with reference to FIG.

FIG. 9A is a plan view of two right-handed circularly polarized patch electrodes having different installation directions, and FIG. 9B is a cross-sectional view taken along the line BB of FIG. 9A. . Here, the patch electrodes 22A and 22B that emit right-hand circularly polarized waves are arranged at intervals d on the x-axis. In order to set the maximum radiation direction (main beam direction) of the radio wave to the angle θ with respect to the z-axis, the patch electrodes 22A and 22B and the patch electrodes 22A and 22B have the same phase in the θ direction. Power may be supplied to 22B. Patch electrodes 22A and 22
When B is fed in phase and each radiated radio wave is observed at a sufficiently long distance in the θ direction, a phase difference corresponding to the distance difference S shown in FIG. 9B occurs. That is, the patch electrode 2
With reference to 2A, the phase of the radio wave radiated from the patch electrode 22B is advanced by a phase difference corresponding to the distance difference S. Therefore, if power is supplied so as to delay the radio wave radiated by the patch electrode 22B by a phase difference corresponding to the distance difference S, the phase of the radio wave radiated by the patch electrode 22B becomes equal to the phase of the radio wave radiated by the patch electrode 22A and the θ direction. , A maximum radiation beam is obtained in the θ direction. That is, the main beam is directed in the θ direction. Here, assuming that a phase difference corresponding to the distance difference S is β, β is β = −360 · S / λ = −360 · d ·
It is given by sin θ / λ (degrees) (where λ is the wavelength of the radiated radio wave). The phase difference β corresponding to the distance difference S can be realized by using a phase shifter. However, when the radio wave is circularly polarized, the patch electrode can be easily rotated by rotating the patch electrode around the feeding point. Beam tilt becomes possible. FIG. 9 shows a state in which the patch electrode 22B is rotated by an angle corresponding to the phase difference β with respect to the patch electrode 22A. In this state, the phase of the radio wave emitted by the patch electrode 22B is equal to the phase of the radio wave emitted by the patch electrode 22A. Therefore, the patch electrodes 22A and 22B
Combine the radio waves radiated from each other to obtain the maximum radiation in the θ direction.

[0006] The planar antenna 20 constructed as described above is mounted on a moving body such as an automobile in a substantially horizontal state.
When used as a tracking-type planar antenna that receives radio waves from a satellite, the inclination angle of the main beam of the planar antenna 20 with respect to the antenna surface is made to substantially match the elevation angle of the satellite, so that the planar antenna 20 can be moved in the azimuth direction. The satellite can be tracked only by rotating. That is, a radio wave from a satellite is received by each patch electrode 22 of the planar antenna 20, introduced into a radial waveguide 25 from a feed pin 24 and coupled to a probe 26, and then shown via a coaxial cable 27. If the frequency is converted by the LNB and input to the receiver, the satellite can be tracked only by rotating the planar antenna 20 only in the azimuth direction. Here, probe 2
The radio waves radiated from each feed pin 24 are in the same phase in each of the patch electrodes 22 on the same row with the center 6, but in each of the patch electrodes 22 in two different rows, each of the feed pins 24 is different. The radio waves radiated from are different.
That is, the phase of the radio wave radiated at the power supply pins 24 of the patch electrodes 22 in the outer row is delayed more. Therefore, the planar antenna 20 beam tilted in a predetermined direction
In order to make the radio waves received by each patch electrode 22 the same phase, the installation direction of each patch electrode 22 is adjusted so that the phase of the radio wave radiated from each feed pin 24 is corrected. Just design.

[0007]

The elevation angle of a satellite varies greatly depending on the area where the satellite is received. For example, even in Japan, the elevation angle of the satellite differs by about 12 degrees between East Japan and West Japan. In the planar antenna described above, the beam width of the main beam in the elevation angle direction is about 6 degrees, so that the installation direction of each patch electrode needs to be set to an optimum angle in advance in accordance with the elevation angle of the target satellite.

However, in the conventional planar antenna 20 described above, a large number of patch electrodes 22 are formed on the surface of the dielectric substrate 21 by etching the copper foil provided on the entire surface of the dielectric substrate 21. Since the pattern is formed in the direction, the installation direction of each patch electrode 22 is determined by the mask shape serving as the original. Therefore, in the case of manufacturing several types of planar antennas 20 having different elevation angles of the main beam, each time the mask serving as an original must be replaced, the installation direction of each patch electrode 22 must be set to the optimum angle. However, there is a problem that the production cost rises due to the lack of the device. Note that such a problem is not limited to a planar antenna used as a tracking type, but also occurs in a planar antenna used as a fixed type for home use.

The present invention has been made in view of such a situation of the prior art, and an object of the present invention is to provide a highly versatile planar antenna capable of easily changing the direction of a main beam. .

[0010]

In order to achieve the above object, a planar antenna according to the present invention comprises a plurality of patch units of the same shape formed by forming patch electrodes on the surface of a dielectric substrate symmetrical with respect to a feed pin. And a ground plate having a large number of through holes into which the power supply pins are inserted, and the patch units are mounted on the ground plate.

In the planar antenna configured as described above,
By rotating the patch unit on the ground plate around its feeding pin, the patch electrodes formed on the surface of each patch unit can be installed at the optimum angle according to the required main beam direction. The direction of the main beam can be easily changed only by preparing a large number of patch units. Also, since a large number of patch units are mounted on the ground plate at predetermined intervals, the usage rate of the dielectric substrate is lower than when a large number of patch electrodes are formed on the surface of one dielectric substrate. Greatly reduced, and the cost can be reduced accordingly.
In addition, since the ground plate functions as a common ground electrode for each patch unit, the configuration of each patch unit itself can be simplified, and the cost can be reduced from this point as well.

In the above configuration, it is preferable that a guide plate having a large number of guide holes is fixed on the ground plate, and the patch holes guide the patch unit in the direction of rotation about the power supply pin. When such a guide plate is used, the patch unit can be easily and reliably installed in a desired rotation direction.

In this case, the external shape of the dielectric substrate in the patch unit may be any shape as long as it is symmetrical with respect to the power supply pin. In particular, it is preferable that the dielectric substrate having the circular external shape is guided by the circular guide hole. By doing so, the patch unit can be more reliably rotated, and the mounting density of the patch unit on the ground plate can be increased. At this time, it is preferable to form a rotation engaging portion on a portion of the dielectric substrate other than the patch electrode, because a jig such as an automatic machine can be engaged with the engaging portion to rotate the patch unit.

In the above configuration, one of the dielectric substrate and the guide plate of the patch unit is provided with a scale along the circumferential direction, and the other is cooperated with the scale to provide a rotation angle of the patch unit. It is preferable to provide a pointer indicating that the installation direction of the patch unit can be visually confirmed.

Further, in the above configuration, it is preferable that a protective sheet is adhered to the guide plate and the surface of each patch unit. If such a protective sheet is used, the adhesive surface of the protective sheet shifts in the rotation direction of the patch unit. At the same time, the patch unit is adhered to the guide plate and the patch unit can be pressed in the direction of the ground plate.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of a planar antenna according to an embodiment of the present invention, and FIG. 2 is an antenna provided in the planar antenna. FIG. 3 is a perspective view of a base, FIG. 3 is a sectional view of the antenna base, FIG. 4 is a plan view of a patch unit provided in the planar antenna, and FIG. 5 is a sectional view of the patch unit.

As shown in FIG. 1, a planar antenna 1 according to this embodiment includes a ground plate 3 fixed to a radial waveguide 2, a guide plate 4 fixed on the ground plate 3, It is composed of a number of patch units 5 positioned by the guide plate 4 and a protective sheet 6 covering the guide plate 4 and a group of patch units 5. Although not shown, the center of the bottom surface of the radial waveguide 2 is not shown. , A probe is attached in the same manner as in the prior art described above, and this probe is connected to the LNB via a coaxial cable.

As shown in FIGS. 2 and 3, the ground plate 3 made of a metal plate and the guide plate 4 made of synthetic resin are both formed in a circular shape.
And the guide plate 4 are joined and integrated by bonding or the like to form the antenna base 7. A large number of through holes 3 a are formed in the ground plate 3.
“a” sets a plurality of concentric circles on the ground plate 3 and is arranged on the circumference of these concentric circles at equal intervals. The guide plate 4 has a large number of guide holes 4a having a diameter larger than that of the through holes 3a.
a has the same center as the corresponding through hole 3a. The numbers of the through holes 3a and the guide holes 4a differ depending on the use of the planar antenna 1. In the case of the planar antenna 1 according to the present embodiment, the diameters of the ground plate 3 and the guide plate 4 are 30 cm, and the through holes 3a and the guide holes 4a. Are 330 in each case, the diameter of the through hole 3a is 1.6φ, and the guide hole 4
The diameter of a is 13φ.

As shown in FIGS. 4 and 5, the patch unit 5 includes a circular dielectric substrate 8 made of a dielectric material having a small relative dielectric constant such as polytetrafluoroethylene (trade name: Teflon), It comprises a patch electrode 9 formed on the surface of the substrate 8 and a power supply pin 10 soldered to a power supply point of the patch electrode 9, and the power supply pin 10 passes through the center of the dielectric substrate 8 and extends downward. Extending to That is, the outer shape of the dielectric substrate 8 is a circle having a radius r centered on the power supply pin 10, and the patch electrode 9 is formed in a part of the circle. The thickness of the dielectric substrate 8 is the guide plate 4
And the diameter of the dielectric substrate 8 is equal to that of the guide hole 4a.
It is almost the same size. Also, the patch electrode 9 of the dielectric substrate 8
Notches 8a and holes 8b as rotating engagement portions
The cut 8a and the hole 8b are formed at positions facing each other with the power supply pin 10 interposed therebetween. A pair of cutouts 9 a are formed on the outer peripheral edge of the patch electrode 9, and the cutouts 9 a face each other on a straight line passing through the center point of the patch electrode 9. Such a patch electrode 9 is formed by etching a copper foil provided on one surface of the dielectric substrate 8. Such a patch unit 5 is inserted into each of the guide holes 4 a of the guide plate 4, and each power supply pin 10 passes through the through hole 3 a of the ground plate 3 and reaches the inside of the radial waveguide 2. ing. Here, the configuration of each patch unit 5 is all the same, but each patch unit 5 is set to an optimum angle in the corresponding guide hole 4a in accordance with the elevation direction of the main beam required for the planar antenna 1. ing. At that time, patch unit 5
Rotates around the feed pin 10, and the outer periphery of the dielectric substrate 8 is guided in the rotational direction along the guide hole 4a.

The protective sheet 6 is made of a synthetic resin film having high weather resistance and low radio wave absorption. The protective sheet 6 is adhered to the surface of the guide plate 4 and each patch unit 5 so as to cover the patch unit 5. Each of the patch units 5 is prevented from slipping in the direction of rotation by the protective sheet 6 and, at the same time, is pressed down in the direction of the ground plate 3 to prevent the patch unit 5 from falling off from the antenna base 7.

When manufacturing the planar antenna 1 configured as described above, first, the ground plate 3 and the guide plate 4 are joined and integrated to assemble the antenna base 7, and a patch is formed in each guide hole 4 a of the antenna base 7. After each of the units 5 is assembled (inserted), each patch unit 5 is rotated in the guide hole 4a in accordance with the required elevation direction of the main beam. In this case, a jig (not shown) is engaged with the notch 8a and the hole 8b of each patch unit 5, and the jig is rotated using an automatic machine in which information on the rotation angle of each patch unit 5 is stored. Each of the patch units 5 can be easily positioned in a desired installation direction. Thereafter, when the protection sheet 6 is adhered to the guide plate 4 and the surface of each patch unit 5, the protection sheet 6 prevents the rotation of each patch unit 5 in the rotation direction, and at the same time, the antenna base of each patch unit 5. 7 is prevented from coming off, and a finished product of the planar antenna 10 can be obtained.

As described above, according to the planar antenna 1 of the present embodiment, each patch unit 5 is connected to its feeding pin 10
, The patch electrodes 9 formed on the surface of each patch unit 5 can be installed at an optimum angle in accordance with the required main beam direction. The direction of the main beam can be easily changed only by preparing a large number of. Therefore, when the planar antenna 1 is used as a fixed antenna for home use, or when it is mounted on a mobile object such as an automobile and used as a tracking antenna, it depends on the elevation angle of the satellite in the receiving area where the planar antenna 1 is used. It is only necessary to adjust the rotation direction of each patch unit 5 to the optimum position, and the versatile planar antenna 1 can be realized.

Further, since a large number of patch units 5 are mounted on the ground plate 3 at predetermined intervals,
Compared with the conventional example in which a large number of patch electrodes are formed on the surface of one dielectric substrate, the usage rate of the dielectric substrate is greatly reduced, and the cost can be reduced accordingly. For example, in the case of a 30 cm planar antenna on which 330 patch electrodes are formed, the conventional example requires a dielectric substrate of 30 cm × 30 cm = 900 cm ² , whereas the present embodiment example requires a dielectric substrate of 1.3 cm × 1.3 cm. * 330 pieces = 558 cm ² of the dielectric substrate 8 is sufficient, and the usage rate of the dielectric substrate is about 60%.
In addition, since the ground plate 3 functions as a common ground electrode for each patch unit 5, the patch electrodes 9 can be formed in a pattern from the dielectric substrate 8 made of a single-sided copper foil, and the soldering of the power supply pins 10 is simplified. For example, the configuration of each patch unit 5 itself can be simplified,
From this point, the cost can be reduced.

A guide plate 4 is joined to and integrated with the ground plate 3 to form an antenna base 7, and each of the patch units 5 is guided in a rotational direction by a number of guide holes 4 a provided in the guide plate 4. Thus, each patch unit 5 can be easily and reliably installed in a desired rotation direction. At this time, since the guide hole 4a of the guide plate 4 and the dielectric substrate 8 of the patch unit 5 are both circular, the outer periphery of the dielectric substrate 8 is
a, and the mounting density of each patch unit 5 on the ground plate 3 can be increased. Further, the patch unit 5
Since the cut 8a and the hole 8b are formed in the dielectric substrate 8, the patch unit 5 can be easily rotated by engaging a jig such as an automatic machine with the cut 8a and the hole 8b.

Further, since the protection sheet 6 is adhered to the surfaces of the guide plate 4 and each patch unit 5, the protection unit 6 can fix each patch unit 5 incorporated in the guide plate 4 and protect the antenna surface. it can.

In the embodiment shown in FIG. 6, a scale 11 is provided along the circumferential direction on the periphery of the dielectric substrate 8 in each patch unit 5, and a guide hole 4a in each guide plate 4 for guiding the patch unit 5 is provided. Pointer 12 near
Is provided. The scale 11 and the pointer 12 are formed by a method such as printing, and the pointer 12 is formed at the same position for all the guide holes 4a. With this configuration, the rotation angle of each patch unit 5 can be visually confirmed by the relative position of the scale 11 and the pointer 12, and, for example, the installation direction of each patch unit 5 can be manually adjusted. On the contrary, the pointer 12 is attached to the patch unit 5.
The same effect can be obtained by providing the scale 11 on the guide plate 4 side.

[0027]

The present invention is embodied in the form described above, and has the following effects.

A plurality of patch units having the same shape formed by forming patch electrodes on the surface of a dielectric substrate symmetrical with respect to the power supply pins; and a ground plate having a large number of through holes into which the power supply pins are inserted. According to the planar antenna configured to mount each patch unit on the ground plate, the patch formed on the surface of each patch unit is rotated by rotating each patch unit on the ground plate around its feeding pin. Since the electrodes can be installed at the optimal angle according to the required main beam direction, the main beam direction can be easily changed only by preparing a large number of patch units of the same shape, and a highly versatile planar antenna can be obtained. Can be realized. Also, since a large number of patch units are mounted on the ground plate at predetermined intervals, the usage rate of the dielectric substrate is lower than when a large number of patch electrodes are formed on the surface of one dielectric substrate. Because it is greatly reduced, the cost can be reduced accordingly, and the ground plate functions as a common ground electrode for each patch unit,
The configuration of each patch unit itself can be simplified, and the cost can be reduced from this point as well.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a planar antenna according to an embodiment of the present invention.

FIG. 2 is a perspective view of an antenna base provided in the planar antenna.

FIG. 3 is a sectional view of the antenna base.

FIG. 4 is a plan view of a patch unit provided in the planar antenna.

FIG. 5 is a cross-sectional view of the patch unit.

FIG. 6 is a plan view showing a main part of a planar antenna according to another embodiment of the present invention.

FIG. 7 is an explanatory diagram of a planar antenna according to a conventional example.

FIG. 8 is a detailed view of a patch electrode provided in the planar antenna.

FIG. 9 is an explanatory diagram illustrating two patch electrodes that are beam tilted.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Planar antenna 2 Radial waveguide 3 Ground plate 3a Through hole 4 Guide plate 4a Guide hole 5 Patch unit 6 Protective sheet 7 Antenna base 8 Dielectric substrate 8a Cut 8b Hole 9 Patch electrode 9a Notch 10 Feeding pin 11 Scale 12 Guideline

Claims (6)

[Claims] A plurality of patch units having the same shape formed by forming patch electrodes on the surface of a dielectric substrate symmetrical with respect to the power supply pins; a ground plate having a plurality of through holes into which the power supply pins are inserted; Wherein each of the patch units is mounted on the ground plate. 2. The device according to claim 1, wherein a guide plate having a plurality of guide holes is fixed on the ground plate, and the patch unit guides the patch unit in a rotational direction around the power supply pin by the guide holes. A planar antenna characterized in that: 3. The planar antenna according to claim 2, wherein the outer shapes of the dielectric substrate and the guide hole are both circular. 4. The planar antenna according to claim 3, wherein a rotation engaging portion is formed on a portion of the dielectric substrate other than the patch electrode. 5. The scale according to claim 3, wherein a scale is provided on one of the dielectric substrate and the guide plate along a circumferential direction, and the other is cooperated with the scale on the other. A planar antenna having a pointer indicating a rotation angle of a patch unit. 6. The planar antenna according to claim 2, wherein a protective sheet is adhered to surfaces of the guide plate and each of the patch units.