JP2002111376A - Polarized wave diversity antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable polarized wave diversity antenna. SOLUTION: Since a matrix plate 23 is formed so that a slot 21 and 22, which radiate two orthogonal direction polarized waves, are located separately from each other and are orthogonal each other on extended lines, micro strip lines 6 and 7 can be formed without crossing. According to this arrangement, there is no need to form a through-hole 8, and the machining process for the through-hole becomes unnecessary and the cost is reduced. Since there is no through-hole 8, the life is extended and the reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarization diversity antenna.

[0002]

2. Description of the Related Art In recent years, with the development of wireless communication technology, mobile communication using microwaves has been actively performed.

By the way, when a radio wave from a transmitter is received while moving, fading may be caused by a multiplex wave in which a reflected wave reflected from a high-rise building or the like and a direct wave from the transmitter are superimposed. As means for preventing such fading, diversity reception is used.
Diversity reception is to receive a plurality of input waves and combine them to make the output uniform.

[0004] Diversity reception includes spatial diversity, directional diversity, frequency diversity, time diversity, and polarization diversity. Space diversity combines the outputs of a plurality of spaced antennas. Directivity diversity arranges a plurality of directional antennas (for example, Yagi antennas) in different directions from each other. Are synthesized.
Frequency diversity is a technique in which radio waves transmitted at different frequencies are received by one antenna and the outputs are combined, and time diversity is a technique in which the output from one antenna and the output via a time delay circuit are combined. Things. In the polarization diversity, a transmitter transmits a horizontal polarization and a vertical polarization at the same time, and a receiver receives and combines the horizontal polarization and the vertical polarization simultaneously with a diversity antenna.

Accordingly, a polarization diversity antenna is indispensable for performing polarization diversity.

FIG. 7 is an external perspective view showing a conventional example of a polarization diversity antenna.

This polarization diversity antenna 1 is provided on a dielectric substrate 2 and one (upper side in the figure) main surface of the dielectric substrate 2 and has a cross-shaped shape which radiates polarized waves in two directions orthogonal to each other. Ground plate 4 made of a conductor having slots 3 formed
And a power supply line pattern 5 formed in the slot 3 on the dielectric substrate 2, and two microstrip lines 6 and 7 formed on the other (lower side in the figure) surface of the dielectric substrate 2. A through hole 8 formed to penetrate through the dielectric substrate 2 for connecting one of the power supply microstrip lines 6 and the line pattern 5;
A dielectric plate 10 supported by a support 9 made of a conductor (or a dielectric) so as to be parallel to the dielectric substrate 2 on one surface side of the dielectric plate 2, and arranged on the dielectric plate 10 so as to face the slot 3. And the parasitic element 11 formed.

The parasitic element 11 is for widening the frequency band of the polarization diversity antenna 1, and the through hole 8 is for preventing the microstrip lines 6, 7 from intersecting.

In such a polarization diversity antenna 1, a signal propagating through the microstrip lines 6 and 7 is transmitted from the slot 3 formed in the ground plane 4 to the parasitic element 11 side perpendicularly to the ground plane 4 (the upper side in the figure). ).

[0010]

By the way, the conventional polarization diversity antenna 1 shown in FIG.
In order to prevent the feed lines of both polarizations from intersecting with each other at the center, a part of the line is formed on the opposite surface and connected by a through hole or the like. Therefore, when the printed circuit board including the dielectric substrate 2, the ground plane 4, and the microstrip lines 6, 7 is formed, the through-holes 8 are formed. Moreover, since the through hole 8 is formed in the polarization diversity antenna 1, there is a problem that the life is shortened, the delivery time is lengthened, and the reliability is reduced.

An object of the present invention is to solve the above problems and to provide a highly reliable polarization diversity antenna.

[0012]

In order to achieve the above object, a polarization diversity antenna according to the present invention is provided on a dielectric substrate and on one main surface of the dielectric substrate.
A ground plate made of a conductor in which a pair of slots that emit polarized waves in different directions are separated from each other and are orthogonal to each other on an extended line, and a microstrip for power supply formed on the other main surface of the dielectric substrate It comprises a line and a parasitic element supported by a support member so as to be parallel to one main surface of the dielectric substrate and to face the slot.

In addition to the above configuration, in the polarization diversity antenna of the present invention, a plurality of parasitic elements are arranged in a line on the same plane, and a slot adjacent to a position of the base plate facing each parasitic element is orthogonal on an extension line. A plurality of pairs of slots may be formed so that the power supply microstrip lines are connected in parallel on the other main surface side of the dielectric substrate.

According to the present invention, since the slots for emitting polarized waves in two orthogonal directions are separated from each other and are formed on the ground plane so as to be orthogonal to each other on an extension line, the respective power supply microstrip lines cross each other. It can be formed without performing. Therefore, it is not necessary to form a through hole, and the number of working steps is reduced by that much, so that the cost is reduced. Further, since there is no through hole, the life is extended and the reliability is improved.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is an external perspective view showing an embodiment of the polarization diversity antenna of the present invention. Note that the same members as those of the conventional example shown in FIG.

The polarization diversity antenna 20 includes a pair of slots 21 provided on the dielectric substrate 2 and one (upper side in the figure) main surface of the dielectric substrate 2 for radiating polarized waves in two orthogonal directions. , 22 are spaced apart from each other and are formed so as to be orthogonal to each other on an extended line, and a power supply microstrip formed on the other (lower side in the figure) main surface of the dielectric substrate 2. Lines 6 and 7 and dielectric substrate 2
Parasitic element 11 supported by a support member so as to be parallel to one of the main surfaces and to face slots 21 and 22.
It is composed of Microstrip lines 6, 7
Is set so that the longitudinal direction of the slots 21 and 22 and the end portions 6a and 7a are orthogonal to each other at a position directly below the center of the slots 21 and 22 so as to perform electromagnetic coupling power supply to the slots 21 and 22. Is formed.

The support member is composed of a column 9 having conductors (or dielectrics) provided at the four corners of the dielectric substrate 2 at the lower end, and a dielectric plate 10 having four corners attached to the upper end of the column 9. . The parasitic element 11 may be provided on either the front surface or the back surface of the dielectric plate 10.

In the polarization diversity antenna 20, the signal propagating through the microstrip lines 6, 7 is:
The light is radiated from the slots 21 and 22 formed in the base plate 23 vertically to the base plate and toward the parasitic element 11 (upper side in the figure).

Since the polarization diversity antenna 20 is configured as described above, the slots 21 and 22 are formed so as to be orthogonal to each other with respect to the ground plane 23, so that the power supply microstrip lines 6 and 7 are provided. Can be formed without crossing. For this reason, it is not necessary to form the through-hole 8 unlike the conventional case, and the number of working steps is reduced by that much, so that the cost is reduced. Further, since there is no through hole 8, the delivery time can be shortened, the service life is prolonged, and the reliability is improved.

FIG. 2 is a diagram showing a voltage standing wave ratio (VSWR) characteristic of the polarization diversity antenna shown in FIG.
The horizontal axis is the frequency axis, and the vertical axis is the VSWR axis.

FIG. 2 shows that the bandwidth ratio is 14% (VSWR <1.
It can be seen that the wide band of 4) is realized.

FIG. 3 is a diagram showing the isolation characteristics of the polarization diversity antenna shown in FIG. 1. The horizontal axis is the frequency axis, and the vertical axis is the isolation axis.

FIG. 3 shows that good results were obtained with isolation <14 dB or less.

FIG. 4 is a characteristic diagram showing the horizontal directivity of the polarization diversity antenna shown in FIG. 1. The horizontal axis is the angle axis, and the vertical axis is the electric field intensity axis.

FIG. 4 shows that a beam having a half width of about 60 degrees is emitted.

FIG. 5 is a characteristic diagram showing the vertical plane directivity of the polarization diversity antenna shown in FIG. 1. The horizontal axis is the angle axis, and the vertical axis is the electric field intensity axis.

FIG. 5 shows that a beam having a half width of about 60 degrees is emitted. Although there is a deviation in the radiation direction depending on the plane of polarization, this can be solved by arranging the elements as described later.

Here, when the position on the base plate 23 corresponding to the center of the parasitic element 11 is displaced from the symmetry axis of the pair of slots 21 and 22, the radiation of the radio waves radiated from the slots 21 and 22 is performed. There is a concern that the direction may be inclined with respect to the normal of the base plate 23.

However, by arranging a plurality of polarization diversity antennas 20 shown in FIG. 1, the beam width and the radiation direction of the radiated radio wave are changed according to the interval between the arrangement and the position of the high frequency fed to the line pattern. This can be solved by optimizing the phase difference.

For example, if the element spacing (slots 21 and 22 and the parasitic element 11) is set to about half of the used wavelength, the number of used elements is set to about 10, and the feeding phases are all the same, radio waves are synthesized and almost the ground plane 23 can be emitted in a direction perpendicular to the direction.

FIG. 6 is an external perspective view showing another embodiment of the polarization diversity antenna of the present invention.

The difference from the embodiment shown in FIG. 1 is that a plurality of polarization diversity antennas are arranged.

That is, in the polarization diversity antenna 30, a plurality (four, but not limited to, four in the figure) of the parasitic elements 11-1, 11-2, 11-3 and 11-4 are composed of the dielectric plate 31. Are arranged in a line on the front surface (or the back surface) of the base plate 32, that is, on the same plane.
-1 to 11-4, adjacent slots (slot 22-1 and slot 21-2, slot 22
-2 and the slot 21-3, and the slot 22-3 and the slot 21-4) are formed so that a plurality of pairs of the slots 21-1 to 21-4 and 22-1 to 22-4 are orthogonal to each other on the extension line. Slots 21-1 to 21- of dielectric substrate 33
4, 22-1 to 22-4 and end portions 6a-1 to 6a-4, 7a-1 to 7a- formed to perform electromagnetic coupling type power supply.
4 are connected in parallel by microstrip lines 34 and 35, respectively.

By arranging a plurality of polarization diversity antennas 20 as shown in FIG. 1, deviation in the radiation direction due to the polarization plane is eliminated, and the through-hole 8 is formed in the same manner as the polarization diversity antenna 20. It is not necessary to perform the operation, and the number of work steps is reduced by that much, so that the cost is reduced. Further, since there is no through hole 8, the delivery time can be shortened, the service life is prolonged, and the reliability is improved.

[0036]

In summary, according to the present invention, the following excellent effects are exhibited.

It is possible to provide a highly reliable polarization diversity antenna.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing an embodiment of a polarization diversity antenna according to the present invention.

FIG. 2 is a diagram showing a voltage standing wave ratio (VSWR) characteristic of the polarization diversity antenna shown in FIG.

FIG. 3 is a diagram illustrating isolation characteristics of the polarization diversity antenna illustrated in FIG. 1;

FIG. 4 is a characteristic diagram illustrating horizontal plane directivity of the polarization diversity antenna illustrated in FIG. 1;

FIG. 5 is a characteristic diagram showing vertical plane directivity of the polarization diversity antenna shown in FIG.

FIG. 6 is an external perspective view showing another embodiment of the polarization diversity antenna of the present invention.

FIG. 7 is an external perspective view showing a conventional example of a polarization diversity antenna.

[Explanation of symbols]

 2 Dielectric Substrate 6, 7 Microstrip Line 6a, 7a End 9 Support 10 Dielectric Plate 11 Parasitic Element 21, 22 Slot 23 Ground Plate

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5J021 AA07 AB05 FA32 GA08 HA05 JA07 5J045 AA12 AB05 AB06 AB07 DA06 EA07 FA02 HA03 JA04 NA01 5J046 AA04 AA06 AA08 AB08 AB10 PA07

Claims (2)

[Claims] 1. A dielectric substrate and a pair of slots provided on one main surface of the dielectric substrate and radiating polarized waves in two orthogonal directions are separated from each other, and are orthogonal to each other on an extension line. A ground plane formed of the formed conductor, a microstrip line for power supply formed on the other main surface of the dielectric substrate, and a plane parallel to one main surface of the dielectric substrate and opposed to the slot; And a parasitic element supported by the support member as described above. 2. A plurality of parasitic elements are arranged in a line on the same plane, and a plurality of pairs of slots are formed so that adjacent slots at positions opposing each parasitic element on the ground plane are orthogonal to each other on an extended line. 2. The polarization diversity antenna according to claim 1, wherein a microstrip line for feeding power is connected in parallel on the other main surface side of said dielectric substrate.