JPH0435508A - Plane antenna - Google Patents

Abstract

PURPOSE:To secure the cross polarization characteristic and to manufacture the antenna at a low cost by piercing an aperture of a circularly polarized wave shape on a radiation circuit plate, and also, forming additionally a radiation element of a circularly polarized wave shape to a feeding line of a feeding circuit plate, and coupling electromagnetically the radiation element to the aperture. CONSTITUTION:The antenna consists of a ground conductor plate 5, a feeding circuit plate 4, and a radiation circuit plate 1, an aperture 2 of a circularly polarized wave shape is pierced in the radiation circuit plate 1, and also, radiation element 6 of a circularly polarized wave shape is formed additionally to a feeding line of the feeding circuit plate 5, and this radiation element 6 is coupled electromagnetically to the aperture 2. Accordingly, since the radiation element of the radiation circuit plate 1 is the radiation element of the aperture, blanking of a metallic plate which can be manufactured easily and whose manufacturing cost is low can be adopted for manufacturing the radiation circuit plate. In such a way, the cost can be reduced, and the cross polarization performance can be obtained in a wide band.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a planar antenna.

[Conventional Technique #i] Conventional planar antennas have been proposed that are constructed by bending a strip line into a crank shape or are constructed from a plurality of patch elements.

However, these are narrow band 300-400MH for boat fishing.
It has been difficult to achieve sufficient performance over the entire broadcasting band. Furthermore, the loss from the power supply line was large, making it difficult to improve efficiency.

Therefore, in order to achieve high efficiency and wideband, ground conductor board, power supply circuit board,
A triplate-type planar antenna consisting of a radiating circuit board was developed and achieved reception performance comparable to that of a parabolic antenna.

[Problems to be Solved by the Invention] However, although the above-mentioned planar antenna consisting of an annular slot-type radiating element has the same performance as a parabolic antenna, there is a cost problem due to the high cost of the etching process. Furthermore, it has been difficult to ensure cross-polarization characteristics over a wide band.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a planar antenna that is highly efficient, easily ensures cross-polarization characteristics over a wide band, and can be manufactured at low cost. There is something to do.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention provides a planar antenna consisting of a ground conductor plate, a feeding circuit board, and a radiating circuit board, in which the radiating circuit board has an aperture shaped for circularly polarized waves. At the same time, a radiating element shaped for circularly polarized waves is added to the feeding line of the feeding circuit board, and this radiating element is electromagnetically coupled to the aperture.

In the invention as claimed in claim 2, the aperture is formed by a circular or regular polygonal hole, and an edge of the hole intersects with an axis inclined at 45 degrees with respect to a horizontal axis passing through the center, and a protrusion that communicates with the outside of the hole. It is formed by providing a cutout.

The invention according to claim 3 provides an outer circumferential shape that is the same as that formed by overlapping a square and a rectangle inclined at 45 degrees with respect to the horizontal axis passing through the center of the square with a common center. The hole constitutes an aperture, the length of the long side of the rectangle is approximately 10 times the size of one side of the square, and the short side of the rectangle is approximately 17 times the size of one side of the square. .

The invention according to claim 4 has a circle having an inclination of 45 degrees with respect to the horizontal axis passing through the center of the circle, the dimension of the short side is shorter than the diameter of the hole in the circle, and the dimension of the long side is the hole in the circle. The aperture is formed by a hole having the same shape as the outer circumferential shape formed by overlapping rectangles having a common center and a rectangle longer than the diameter of the feed line. It is formed using a solid-type patch element.

According to a sixth aspect of the invention, the radiating element added to the feed line is formed of a helical element.

[Function] According to the present invention, since the radiating element of the radiating circuit board is an aperture radiating element, the punching process of a metal plate, which is easy to manufacture and inexpensive to manufacture, is adopted for manufacturing the radiating circuit board. By manufacturing the radiating circuit board by punching out a metal plate, a radiating circuit board with excellent rigidity can be obtained, resulting in a ground conductor, power supply circuit board, and radiating circuit board. It is possible to improve the accuracy of the interval between antennas and minimize variations in antenna performance.

Furthermore, although electromagnetic coupling between the feed line and the aperture alone can operate as a good planar antenna, in the present invention, a radiating element such as a patch element or a helical element is added to the coupling portion of the feed line with the aperture. As a result, the gain and band can be significantly improved. In particular, it becomes possible to widen the cross-polarization performance, which has traditionally been a problem.

By providing the aperture size with the dimensional relationship as in the invention set forth in claim 3, an antenna with excellent circularly polarized wave performance can be realized, and the aperture shape of the radiation circuit board in the invention set forth in claim 4 can also be achieved. circularly polarized wave performance.

[Example] The present invention will be explained below with reference to Examples.

FIG. 1 shows an exploded perspective view of Embodiment 1, with some parts omitted. A radiating circuit board 1 is formed by punching out a plurality of 2 at equal intervals vertically and horizontally, and a helical element 7 for circularly polarized waves that can be electromagnetically coupled is added to each aperture 2 of this radiating circuit board 1. A feeder circuit board 4 on which a feeder line formed by etching is formed by etching is placed below the radiation circuit board 1 at a certain distance apart, as shown in FIG. Ground conductor plates 5 made of metal plates are arranged at fixed intervals. As shown in FIG. 3, the aperture 2 formed on the radiation circuit board 1 has a dimension a on one side (in the embodiment, a=
12ms) square and its long side dimension is approximately Ja,
In addition, the outer circumferential shape formed when a rectangle with a short side dimension of approximately a/J is overlapped at a 45 degree angle to the horizontal axis passing through the center of the square, as shown in Figure 4, with a common center. Consisting of holes of the same shape, the radiation circuit board l has 20-
It is punched out in 16 rows and 16 columns at regular intervals.

In other words, the aperture 2 is punched out in the form of a square hole with notches communicating outwardly from the edges of a pair of diagonal portions of the square hole.

In this embodiment, the feed circuit board 4 is a printed circuit board on which a circuit pattern is formed by etching, and a helical element 6 as a radiating element is connected to the tip of the feed line. This helical element 6 consists of a helical element with a circumference of 25 mm.

When the feeder circuit board 4 is arranged below the radiation circuit board 1, the feeder line 4a and helical element 6 corresponding to the aperture 2 are arranged as shown in FIG. 5 and are electromagnetically coupled to the aperture 2.

The ground conductor plate 5 is formed using a metal plate such as a commercially available aluminum plate having a thickness of 2 tw, for example.

Here, a dielectric material consisting of an air layer is interposed between the radiation circuit board 1 and the feeder circuit board 4, and between the feeder circuit board 4 and the ground conductor board 5, or a dielectric material is provided to serve as a spacer. A dielectric material made of foamed plastic sheet is interposed.

When we measured the input VSWF, gain, and cross-polarization characteristics of the planar antenna of the example configured as described above, we found that The results shown in the curve were obtained, and as can be seen from this result, a wide band of 11.5 to 12.2 GHz (approximately 700 MHz) was obtained.
Over the period, an efficiency of 64% or more and a cross polarization characteristic of 25 dB or more were obtained. Note that the mouth curves shown in FIGS. 6(a>, (b), and (c) show the characteristics when the helical element 6 is not used, and the superiority of this example compared to these characteristics is that I understand.

Furthermore, compared to the conventional annular slot type antenna in which a printed board is manufactured by an etching process, the manufacturing cost of this embodiment, in which the radiating circuit board 1 is manufactured by punching, is significantly lower.

Etane■1 In Example 1 above, the helical element 6 was used as the radiating element connected to the feed line, but in this example, as shown in FIG. Patch element 3 having a shape in which a portion corresponding to 2% of the area is cut off
Use. Note that the shape of the aperture 2 is the same as that in the first embodiment.

Even in this embodiment having the above-described configuration, the same cross-polarized wave characteristics as in the first embodiment were obtained.

Hinomi ■1 This example uses the patch element 3 as in Example 2, but as shown in FIG. A circular patch element 3 having a shape in which a portion corresponding to 2% in area ratio was cut out was used, and cross-polarization characteristics similar to those in Example 1 were obtained.

K1KA The shape of the aperture 2 in Examples 1 to 3 above was the same as the outer peripheral shape of a combination of a square and a rectangle, but it may also be a combination of a circle and a rectangle as shown in FIG. In the example, for example, a circle with a diameter of 8 m and a rectangle with a long side of 10 mm and a short side of 5 mm have a common center, and the rectangle is tilted by 45 degrees with respect to the horizontal axis passing through the center of the circle. The radiating circuit board 1 is manufactured by forming an aperture layer 2 having the same outer circumferential shape when stacked on top of each other, and drilling a plurality of holes in a metal plate in the same arrangement as in Example 2. The patch element 3 similar to that of the second embodiment is used as the radiation element to be coupled. Of course, the helical element 6 as in the first embodiment or the patch element 3 used in the third embodiment may be used.

In this example, characteristics similar to those of Example 1 were obtained.

Cold 115 In Example 1, the radiation circuit board 1 is formed by punching out the apertures 2 on a metal plate made of aluminum, but in this example, the copper foil part of a commercially available flexible printed board is used as the conductive plate. The aperture 2 was formed by etching, and the same effect as in Example 1 was obtained.

Of course, it goes without saying that the configurations of Embodiments 2, 3, and 4 can also be adopted in this embodiment.

[Effects of the Invention] In the present invention, since the radiating element of the radiating circuit board is an aperture radiating element, the punching process of a metal plate, which is easy to manufacture and inexpensive to manufacture, can be adopted for manufacturing the radiating circuit board, and the cost is reduced. In addition, since it promotes the operation of two types of elements: the radiating element such as a helical element or patch element added to the feed line, and the aperture, it is possible to improve antenna characteristics over an extremely wide band, which solves the conventional problem. This has the effect of making it possible to widen the cross-polarization performance, which previously had been the case. Furthermore, by manufacturing the radiating circuit board by punching out a metal plate, a radiating circuit board with excellent rigidity can be obtained. This has the effect of improving the accuracy of the spacing between the feeding circuit board and the radiating circuit board, and minimizing variations in antenna performance.

By making the aperture size have the dimensional relationship as in the invention set forth in claim 3, an antenna with excellent circularly polarized wave performance can be realized. The shape also has the effect of providing excellent circularly polarized wave performance.

[Brief explanation of drawings]

FIG. 1 is a partially omitted perspective view of Embodiment 1 of the present invention, and FIG.
The figure is a partially omitted cross-sectional view of the same as above, Fig. 3 is an explanatory view of the dimensions of the aperture of the above, Fig. 4 is an explanatory view of the shape of the aperture of the above, and Fig. 5 is an explanatory view of the arrangement relationship between the aperture of the above and the radiation element. , FIG. 6 (a)-(c) are explanatory diagrams of the same characteristics as above,
FIG. 7 is an explanatory diagram of the arrangement relationship between the aperture and the radiating element according to the second embodiment of the present invention, FIG. 8 is an explanatory diagram of the arrangement relation between the aperture and the radiating element according to the third embodiment of the present invention, and FIG. 9 is an explanatory diagram of the arrangement relation between the aperture and the radiating element according to the third embodiment of the present invention. FIG. 4 is an explanatory diagram of the arrangement relationship between the aperture and the radiating element in Example 4; 1 is a radiation circuit board, 2 is an aperture, 3 is a patch element, 4
5 is a power supply circuit board, 5 is a ground conductor plate, and 6 is a helical element. Agent Patent Attorney Stone 1) Long 71 is the radiation circuit board 2 is the aperture 4 is the same name plate Figure 6 (GHz) (GHz) (GHz) Figure 7 Figure 8 Figure 9 1 is the radiation circuit board

Claims (6)

[Claims] (1) In a planar antenna consisting of a ground conductor plate, a feeding circuit board, and a radiating circuit board, an aperture shaped for circularly polarized waves is bored in the radiating circuit board, and an aperture shaped for circularly polarized waves is formed in the feed line of the feeding circuit board. A planar antenna characterized in that a radiating element is additionally formed and the radiating element is electromagnetically coupled to the aperture. (2) The aperture is formed by a circular or regular polygonal hole, and a notch is provided at the edge of the hole that intersects with an axis inclined at 45 degrees with respect to the horizontal axis passing through the center, which communicates and projects to the outside of the hole. A planar antenna characterized by being formed by (3) A square and 4 points for the horizontal axis passing through the center of the square.
An aperture is formed by a hole having the same shape as the outer periphery formed by overlapping rectangles with a 5 degree inclination with a common center, and the dimension of the long side of the rectangle is the dimension of one side of the square. 3. The planar antenna according to claim 2, wherein the short side of the rectangle is approximately 1/√2 times the dimension of one side of the square. (4) A circle with an inclination of 45 degrees to the horizontal axis passing through the center of the circle, the short side dimension is shorter than the diameter of the hole in the circle, and the long side dimension is longer than the diameter of the hole in the circle. 2. The planar antenna according to claim 1, wherein the aperture is formed by a hole having the same shape as the outer circumferential shape formed by overlapping a rectangle with a common center. (5) The planar antenna according to claim 1, wherein the radiating element added to the feed line is formed of a degenerate separation type patch element. (6) The planar antenna according to claim 1, wherein the radiating element added to the feed line is formed of a helical element.