JP2001094337A - Micro strip antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a micro strip antenna which feeds power to the center of the outer shape of a radiation element 12 by a feeding pin 18 from a rear side and matches impedance. SOLUTION: A rectangular radiation element 12 is installed on the surface of a dielectric substrate 10 and a ground board 14 is installed on a rear face. Power is fed to the center of the outer shape of the radiation element 12 from a rear side through the dielectric substrate 10 by a feeding pin 18 and a feeding pint 20 is installed. A U-shaped slot 22 which surrounds the feeding point 20 and in which a part of the surrounding is opened is installed in the radiation element 12 so that it is line-symmetrical against one axis and is non-line symmetrical with respect to the other axis in the two axes which are parallel to the rectangular side of the outer shape and are orthogonal through the center. A straight polarized wave is transmitted/received in the direction of one axis becoming line symmetry.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microstrip antenna for feeding power to the center of the outer shape of a radiating element from the back.

[0002]

2. Description of the Related Art FIGS. 11A and 11B show an example of a conventional microstrip antenna for linear polarization, in which FIG. 11A is a front view and FIG. 11B is a sectional view. In the conventional microstrip antenna shown in FIG. 11, a square radiating element 12 made of a conductive foil is provided on the surface of a dielectric substrate 10, and a ground plate 14 made of a conductive foil is provided on the entire back surface.
A power supply connector 16 is provided on the back surface of the dielectric substrate 10, and a power supply pin 18, which is a central conductor of the power supply connector 16, penetrates through the dielectric substrate 10 from the back side and is electrically connected to the radiating element 12 to form a power supply point 20. You. The feed point 20 is parallel to the side of the outer shape of the radiating element 12, passes through the center, and is orthogonal to XX ′.
Axis and the YY ′ axis are arranged at positions that are axisymmetric with respect to one XX ′ axis and non-symmetric with respect to the other YY ′ axis. . That is, the feeding point 20 is disposed at a position shifted from the center on the XX ′ axis. Here, in order to achieve impedance matching between the radiating element 12 and the feeding pin 18, the feeding point 20 is set at a position shifted from the center. With such a configuration, line-symmetric XX ′
Axial linear polarization can be transmitted and received. The radiating element 1
2 is not limited to a square, but may be a rectangle such as a rectangle.

FIG. 12 is a front view of an example of a conventional microstrip antenna for circular polarization. In the conventional microstrip antenna shown in FIG. 12, a feeding point 20 is disposed at a position obliquely displaced from the center on a line connecting two opposing corners of a rectangular radiating element 12. That is,
The feed point 20 is located at a position that is non-linearly symmetric with respect to both the XX ′ axis and the YY ′ axis. Then, impedance matching between the radiating element 12 and the feeding pin 18 is achieved in both the XX ′ axis direction and the YY ′ axis direction. Therefore, a circularly polarized wave in which two orthogonal linearly polarized waves in the XX ′ axis direction and the YY ′ axis direction are combined can be transmitted and received.

[0004]

The above-described conventional microstrip antenna has a radiating element 12 and a feeding pin 18.
In order to achieve impedance matching, the feed point 20 is arranged at a position shifted from the center of the radiating element 12. In order to determine the optimum position of the feeding point 20 with respect to the radiating element 12, adjustment must be made experimentally in order to be affected by peripheral structures such as radomes and circuit components. In addition, re-processing such as adjusting the position of the hole for passing the power supply pin 18 through the dielectric substrate 10 and changing the rear-side circuit arrangement due to the change in the position of the hole is complicated, and it takes much time and time to complete the design. It took time and effort. Further, in the circularly polarized array antenna, in order to adjust the overall directional characteristics, the posture of each radiating element 12, 12,.
In some cases, the rotation adjustment may be performed on 0. In the adjustment in such a case, when the above-described microstrip antenna is used, it is extremely complicated to adjust and change the position of the feeding point 20 in order to rotationally adjust the attitude of the radiating element 12. If the attitude of the radiating element 12 is rotated about the point 20, a large number of radiating elements 12, 1
The intervals of 2 ... are shifted, and as a result, a desired directional characteristic cannot be easily obtained.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances of the prior art, and has as its object to provide a microstrip antenna capable of feeding power from the rear side to the center of the outer shape of a radiating element with a feed pin and achieving impedance matching. And

[0006]

In order to achieve the above object, a microstrip antenna according to the present invention is provided with a radiating element on a front surface of a dielectric substrate and a ground plate on a back surface, wherein the radiating element is provided on the dielectric element. A microstrip antenna penetrating a substrate and feeding power from a rear side with a feeding pin, wherein a feeding point for feeding with the feeding pin is provided at the center of the outer shape of the radiating element, and the radiating element surrounds and surrounds the feeding point. Is provided with a slot that is partially open.

The slot may be provided in a U-shape, V-shape, U-shape or C-shape surrounding the feeding point.

The outer shape of the radiating element is rectangular, and two axes parallel to the sides of the rectangular, passing through the center, and orthogonal to each other,
The slot may be provided so as to be linearly symmetric with respect to one axis and non-linearly symmetric with respect to the other axis so that linearly polarized waves can be transmitted and received in one axial direction which is symmetrical with the axis.

The outer shape of the radiating element is rectangular, and two axes parallel to the sides of the rectangular, passing through the center, and orthogonal to each other,
The slots may be provided so as to be non-linearly symmetric with respect to any axis so that circularly polarized waves can be transmitted and received.

Further, the outer shape of the radiating element has a shape in which two opposing corners of a rectangle are cut off by oblique sides, and the slot is aligned with one axis with respect to two axes that are parallel to the sides of the rectangle and pass through the center and are orthogonal. It may be provided so as to be linearly symmetric and non-linearly symmetric with respect to the other axis so that circularly polarized waves can be transmitted and received.

The outer shape of the radiating element is circular or elliptical, and the slot is symmetric with respect to one axis with respect to two axes passing through the center of the circular or elliptical and orthogonal to the other axis. It may be provided so as to be non-linearly symmetric so that linearly polarized waves can be transmitted and received in one axial direction that is symmetrical with the line.

Further, the outer shape of the radiating element is circular and has a shape in which a position opposite to the outer edge is notched in a concave shape. With respect to the two axes, the slots may be provided so as to be line-symmetric with respect to one axis and non-symmetric with respect to the other axis so as to transmit and receive circularly polarized waves.

[0013] The radiation element may have an elliptical outer shape,
With respect to the major axis and minor axis passing through the center of this ellipse and orthogonal,
The slots may be provided so as to be non-linearly symmetric with respect to any axis so that circularly polarized waves can be transmitted and received.

[0014]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. 1A and 1B show a first embodiment of a microstrip antenna according to the present invention, wherein FIG. 1A is a front view and FIG. 1B is a sectional view. FIG. 2 is an enlarged view of the slot in FIG. 1 and 2, the same or equivalent members as those shown in FIG. 11 are denoted by the same reference numerals, and redundant description will be omitted.

In the microstrip antenna of the present invention shown in FIG. 1, a square rectangular radiating element 12 made of a conductive foil is provided on the surface of a dielectric substrate 10 and a ground plate 14 made of a conductive foil is provided on the entire back surface. Arranged,
A power supply connector 16 is provided on the back surface of the dielectric substrate 10,
Feeding pin 18 serving as the center conductor penetrates through dielectric substrate 10 from the back side and is electrically connected to radiating element 12 to form feeding point 20, similarly to the conventional microstrip antenna shown in FIG. is there. Then, the present invention is different from the conventional example in that a feeding point 20 where the feeding pin 18 is electrically connected to the radiating element 12 is disposed at the center of the outer shape of the radiating element 12. Further, a U-shaped slot 22 having a part of the enclosure opened so as to surround the feed point 20 has a XX ′ axis which is parallel to a side of the outer shape of the radiation element 12, passes through the center, and is orthogonal to YY. Y-axis is symmetrical with respect to the two axes XX,
That is, it is provided to be non-linearly symmetric with respect to the Y ′ axis. Note that the outer shape of the radiating element 12 in the first embodiment is not limited to a square, but may be a rectangular rectangle.

In such a configuration, the feeding point 2 at the center
The impedance value of 0 is the impedance when the feeding point 20 is provided on the virtual line A (shown in FIG. 2) connecting the opening of the U-shaped slot 22 and the feeding between the virtual line A and the center of the radiating element 12. The impedance of the microstrip feeder line having a length Ld and a width Lw connecting the point 20 and the impedance becomes a value corresponding to that connected in series. Therefore, even though the feed point 20 is located at the center of the outer shape of the radiating element 12, the microstrip antenna of the present invention can achieve impedance matching between the feed pin 18 and the radiating element 12. The first embodiment of the microstrip antenna of the present invention is formed to be line-symmetric with respect to the XX 'axis and non-linearly with respect to the YY' axis, similarly to the conventional example shown in FIG. It acts in the same way as the one in which the feeding point 20 is arranged at a position off the center on the -X 'axis. Therefore,
Transmission and reception of linearly polarized waves in the XX ′ axis direction are possible. Note that, as the length Ld from the feeding point 20 to the virtual line A increases, the impedance value at the virtual line A increases, and the delay phase amount from the feeding point 20 increases. Further, the width Lw contributes to the impedance of the feeder line, and the impedance tends to decrease as the width increases. When the external dimensions Lx and Ly of the slot 22 increase, the discontinuous portion of the radiating element which does not have the conventional shape shown in FIG. 11 increases, so that the impedance value in the virtual line A tends to increase. is there. Since the current contributing to the radiation of the radio wave is a current flowing through a portion other than the microstrip feed line between the feed point 20 and the virtual line A, L
When x and Ly increase, the current contributing to radiation among the currents flowing through the radiating element 12 tends to concentrate on the outer peripheral portion of the radiating element 12 and its path lengthens, and the resonance frequency tends to decrease. Therefore, a microstrip antenna capable of transmitting and receiving linearly polarized waves having a desired resonance frequency can be obtained by appropriately adjusting and setting the outer dimensions of the radiating element 12 and the dimensions of the slots 22 experimentally.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a front view of a second embodiment of the microstrip antenna according to the present invention. In the second embodiment shown in FIG. 3, the radiating element 30 has an outer shape in which two opposing corners of a square are cut off with inclined surfaces. A feed point 20 is provided at the center of the rectangle of the outer shape of the radiating element 30, and a U-shaped slot 22 is line-symmetric with respect to the XX 'axis and YY so as to surround the feed point 20. 'Asymmetrical with respect to the axis.

In such a configuration, the feeding point 20 is set at X-
Acting in the same way as the one arranged at a position deviated from the center on the X ′ axis, the radiating element 30 can transmit and receive circularly polarized waves because its two opposing corners are cut off by oblique sides.

A third embodiment of the present invention will be described with reference to FIG. FIG. 4 is a front view of a third embodiment of the microstrip antenna according to the present invention. In the third embodiment shown in FIG. 4, a feeding point 20 is disposed at the center of the outer shape of the rectangular radiating element 12, and a U-shaped slot 32 is formed so as to surround the feeding point 20 so as to surround the feeding point 20. Are provided symmetrically with respect to the line connecting the two corners of the rectangle and asymmetrically with respect to the line connecting the other opposite corners of the rectangle. This is X
It will be provided non-linearly symmetric with respect to both the -X 'axis and the YY' axis. In such a configuration, the feeding point 20
Has the same effect as that disposed at a position obliquely displaced from the center of the radiating element 12. Thus, similarly to the conventional microstrip antenna shown in FIG. 12, circularly polarized waves can be transmitted and received.

Further, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 5 is a front view of a microstrip antenna according to a fourth embodiment of the present invention. In the fourth embodiment shown in FIG. 5, the outer shape of the radiating element 40 is circular. A power supply point 20 is provided at the center thereof.
Are provided so as to be line-symmetric with respect to the XX 'axis and non-symmetrically with respect to the YY' axis. In the fourth embodiment having such a configuration, X
A feed point 20 is provided at a position deviated from the center on the -X 'axis to operate in the same manner as that for achieving impedance matching.
X'-axis linearly polarized waves can be transmitted and received. The outer shape of the radiating element 40 in the fourth embodiment is not limited to a circle, but may be an ellipse.

Further, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a front view of a microstrip antenna according to a fifth embodiment of the present invention. In the fifth embodiment shown in FIG. 6, the radiating element 42 has a circular outer edge X-.
It has a shape in which concave cutouts 44, 44 are provided at two positions facing each other on a line inclined at 45 degrees to the X 'axis and the YY' axis. A feeding point 20 is provided at the center of the radiating element 42. A U-shaped slot 22 is symmetrical about the XX 'axis and non-linear about the YY' axis so as to surround the feeding point 20. Provided symmetrically. In the fifth embodiment having such a configuration, the radiating element 42 is circular and the cutouts 44, 44 are provided at positions facing the outer edges thereof, so that circularly polarized waves can be transmitted and received.

FIG. 7 shows a sixth embodiment of the present invention.
This will be described with reference to FIG. FIG. 7 is a front view of a microstrip antenna according to a sixth embodiment of the present invention. In the sixth embodiment shown in FIG. 7, the radiating element 46 is elliptical, and is disposed with its major axis being the YY 'axis and its minor axis being the XX' axis. The feed point 2 is located at the center of the radiating element 46.
0 is provided, and a U-shaped slot 32 is provided so as to surround the feeding point 20 in a non-symmetric manner with respect to any of the major axis and the minor axis. This is the XX 'axis and Y-
It is provided non-linearly symmetric with respect to any of the Y 'axes. In such a configuration, the feeding point 20 operates in the same manner as that provided at a position shifted obliquely from the center of the radiating element 46, and can transmit and receive circularly polarized waves.

The slots 22, 32 are not limited to the U-shape as described above, but may be a V-shaped slot 50 as shown in FIG. 8, or a U-shaped slot 52 as shown in FIG. And a C-shaped slot 54 as shown in FIG.

[0024]

As described above, since the microstrip antenna of the present invention is constituted, the following special effects can be obtained.

In the microstrip antenna according to the first aspect, a feed point is provided at the center of the radiating element. By providing a slot surrounding the feed point and partially opening the enclosure, Despite the feed point at the center, proper impedance matching can be achieved and the antenna can function as an antenna. And the adjustment of the impedance matching is also possible by adjusting the shape of the slot,
There is no need to adjust the position of the feed point with respect to the radiating element,
This makes it easier to adjust the design, shortens the time required to complete the design, and saves time and effort. Also, in a circularly polarized array antenna, when the attitude of the radiating element is rotationally adjusted to adjust the directional characteristics, the rotational adjustment may be performed about a feed point at the center of the radiating element. Does not occur such that the pitch between them is fluctuated.

In the microstrip antenna according to the second aspect, by appropriately selecting the shape of the various slots, the impedance value according to the length from the feeding point to the opening of the slot and the opening of the slot from the feeding point are determined. It can be adjusted by appropriately combining the impedance values of the feeder lines up to the section.

In the microstrip antenna according to the third or sixth aspect, linearly polarized waves can be transmitted and received by the microstrip antenna having a feed point provided at the center of the radiating element.

In any of the microstrip antennas according to the fourth, fifth, seventh and eighth aspects, circularly polarized waves can be transmitted and received by the microstrip antenna provided with a feed point at the center of the radiating element.

[Brief description of the drawings]

1A and 1B show a first embodiment of a microstrip antenna according to the present invention, wherein FIG. 1A is a front view and FIG. 1B is a cross-sectional view.

FIG. 2 is an enlarged view of a slot in FIG.

FIG. 3 is a front view of a microstrip antenna according to a second embodiment of the present invention.

FIG. 4 is a front view of a third embodiment of the microstrip antenna according to the present invention.

FIG. 5 is a front view of a microstrip antenna according to a fourth embodiment of the present invention.

FIG. 6 is a front view of a microstrip antenna according to a fifth embodiment of the present invention.

FIG. 7 is a front view of a microstrip antenna according to a sixth embodiment of the present invention.

FIG. 8 is a front view showing another example of the slot.

FIG. 9 is a front view showing still another example of the slot.

FIG. 10 is a front view showing still another example of the slot.

11A and 11B show an example of a conventional linearly polarized microstrip antenna for linear polarization, wherein FIG. 11A is a front view and FIG. 11B is a cross-sectional view.

FIG. 12 is a front view of an example of a conventional microstrip antenna for circular polarization.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Dielectric substrate 12, 30, 40, 42, 46 Radiating element 14 Ground plate 18 Feeding pin 20 Feeding point 22, 32, 50, 52, 54 Slot 44 Notch

Claims (8)

[Claims] 1. A microstrip antenna in which a radiating element is provided on a front surface of a dielectric substrate and a ground plate is provided on a back surface, and the radiating element penetrates the dielectric substrate and is fed from a back side with a feeding pin, A microstrip antenna, wherein a feed point for feeding with the feed pin is provided at the center of the outer shape of the radiating element, and the radiating element is provided with a slot surrounding the feed point and having a part of the enclosure opened. . 2. The microstrip antenna according to claim 1, wherein said slot is provided in a U-shape, V-shape, U-shape or C-shape surrounding said feeding point. antenna. 3. The microstrip antenna according to claim 1, wherein the outer shape of the radiating element is rectangular, and the slot is connected to one axis with respect to two axes that are parallel to the sides of the rectangle, pass through the center, and are orthogonal to each other. A microstrip antenna which is symmetrical and non-linearly symmetric with respect to the other axis, and is configured to transmit and receive linearly polarized waves in one axially symmetrical axis direction. 4. The microstrip antenna according to claim 1, wherein the outer shape of the radiating element is rectangular, and the slot is formed with respect to any two axes that are parallel to the sides of the rectangle, pass through the center, and are orthogonal to each other. A microstrip antenna which is provided so as to be non-linearly symmetric and is configured to transmit and receive circularly polarized waves. 5. The microstrip antenna according to claim 1, wherein said radiating element has a rectangular outer shape.
The slot is formed to have a shape lacking a hypotenuse, so that the slot is line-symmetric with respect to one axis and non-linear with respect to the other axis with respect to two axes that are parallel to the sides of the rectangle and are orthogonal to the center. A microstrip antenna provided so as to be able to transmit and receive circularly polarized waves. 6. The microstrip antenna according to claim 1, wherein the radiating element has a circular or elliptical outer shape, and the slot is formed on one axis with respect to two axes passing through the center of the circular or elliptical shape and orthogonal to each other. A microstrip antenna provided so as to be linearly symmetric with respect to the axis and non-linearly symmetric with respect to the other axis, so as to be able to transmit and receive linearly polarized waves in one axis direction that is line symmetric. 7. The microstrip antenna according to claim 1, wherein the radiating element has a circular outer shape, and a position where an outer edge of the radiating element opposes is notched in a concave shape. 4 for the direction
With respect to two axes which are oblique and orthogonal at 5 degrees, the slot is provided so as to be line-symmetric with respect to one axis and non-symmetric with respect to the other axis, so as to be capable of transmitting and receiving circularly polarized waves. Characteristic microstrip antenna. 8. The microstrip antenna according to claim 1, wherein the outer shape of the radiating element is elliptical, and the slot is formed with respect to any axis with respect to a long axis and a short axis passing through the center of the ellipse and orthogonal to each other. A microstrip antenna, wherein the microstrip antenna is provided so as to be non-linearly symmetrical and can transmit and receive circularly polarized waves.