JPH0456502A - Pianar antenna - Google Patents

Abstract

PURPOSE:To realize a planar antenna whose feeder loss is minimized to suit the reception of satellite communication by making a width of a feeder located in the vicinity of a coupling part with a radiation element narrower than the width of other feeders. CONSTITUTION:The antenna consists of a radiation circuit board 1 formed by punching plural apertures 2 being circularly polarized wave radiation elements arranged at an equal interval longitudinally and laterally to a metallic board, a feeder circuit board 4 formed with a feeder coupled electromagnetically with each aperture 2 arranged under the board 1 at a prescribed interval, and a ground conductor board 5 spaced under the board 4 at a prescribed interval. In this case, the width of the feeder 4b in the vicinity of a coupling part 4a of the feeder of the feeding circuit board 4 coupled electromagnetically with each aperture 2 is made narrower than the width of the other feeder 4c. Thus, undesired mutual coupling is minimized and the transmission loss is improved and the planar antenna is adopted even for the reception of a communication satellite in addition to the reception of satellite broadcast.

Description

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

[Prior Art] Conventional planar antennas have been proposed in which one is constructed by bending a strip line into a crank shape, and the other is constructed by a plurality of patch elements.

However, these are narrow band for boat fishing of 300 to 400M.
It has been difficult to provide sufficient performance over the entire broadcast band spanning Hz.

Furthermore, the loss from the power supply line is 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 planar antenna consisting of a radiating circuit board has been developed and has achieved reception performance comparable to that of a parabolic antenna.

[Issue to be solved by the invention WI] However, it has been confirmed that the above-mentioned antenna has performance equivalent to or better than that of a parabola in the case of a large EIRP such as a broadcasting satellite, but it is not suitable for a communication satellite. Like EIRP
In the case of a small antenna (parabolic antenna requires a diameter of 1 m or more), reception efficiency was found to be lower than that of a parabolic antenna due to the feed line loss.

The present invention has been made in view of the above-mentioned drawbacks, and its purpose is to provide a planar antenna configuration that has minimal power feed line loss and is suitable for receiving communication satellites.

[Means for Solving the Problems] The present invention provides a planar antenna consisting of a ground conductor, a feeding circuit, and a radiating circuit, in which the feeding circuit is located near a coupling portion of the feeding circuit that electromagnetically couples with a radiating element of the radiating circuit. The line width of the line is narrower than that of other power supply lines.

[Function] As described above, in the feed line, the line width of the feed line in the vicinity of the coupling part with the radiating element, that is, the part that surrounds the radiating element, is reduced to that of the other feed line, that is, the microwave By making the line width thinner than that of the feeder line in the portion that functions as transmission, we were able to minimize unnecessary mutual coupling and improve transmission loss.

[Detailed description of the invention] 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. In this embodiment, a circularly polarized radiating element is mounted on a metal plate such as aluminum with a thickness of 0.4 mm. barrel aperture 2
A radiation circuit board 1 is formed by punching out a plurality of radiating circuit boards 1 at equal intervals vertically and horizontally, and a power supply circuit that is placed below the radiation circuit board 1 at a certain interval and can be electromagnetically coupled to each aperture 2. It is composed of a feeder circuit board 4 on which a line is formed by etching, and a ground conductor plate 5 made of a metal plate such as a commercially available aluminum plate and placed below the feeder circuit board 4 at a certain distance. Figure 2 shows its cross-sectional configuration, and 6 in the figure is a dielectric layer.

By the way, in the embodiment, as shown in FIG. 3, the line width of the feed line 4b in the vicinity of the coupling portion 4a (indicated by the broken line frame) that electromagnetically couples to the aperture 2 of the feed line of the feed circuit board 4 is The line width of the feed line 4C in other parts is made thicker.

In particular, it is desirable to make the portion from the feeding end to the second T-branch thinner.

Further, the distance between the transmission portion parallel to the thin feed line 4b and the thick feed line 4c is set to be equal to or larger than the width of the feed line 4b.

On the other hand, the aperture 2 formed on the radiation circuit board 1 has a square shape with one side having a dimension a (a-13 mm in the example), the long side dimension being approximately Ja, and the short side dimension being approximately Ja as shown in FIG. With the center common to the rectangle with approximately a/, /F, as shown in Figure 5, 45 points with respect to the horizontal axis passing through the center of the square.
It consists of holes with the same shape as the outer periphery formed when they are stacked at an angle.
It is punched out in 6 rows and 16 columns. 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.

When the feeder circuit board 4 is disposed below the radiation circuit board 1, the coupling portion 4a of the feeder circuit corresponding to the aperture 2 and the aperture 2 are electromagnetically coupled as shown in FIG. Here, it is preferable that the tip of the coupling portion be placed at a position protruding from the center of 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 mm, for example.

Here, 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, there is a dielectric material 6 made of foamed brass that functions as a spacer, as shown in FIG. to intervene in such a way.

The planar antenna of the example constructed as described above has a gain of 0.5 dB compared to a conventional planar antenna using a feeding circuit in which a feeding line is formed with the same line width.
An improved result was obtained, and from this result 11.5 to 12
．． An efficiency of 69% or more was obtained over the 0 GHz band.

The shape of the aperture 2 formed on the radiation circuit board 1 is a square (for example, the - side is 14 m) as shown in FIG.
m) or a circular aperture 2 for linearly polarized waves as shown in FIG. A planar antenna with similar performance was obtained.

In this second embodiment, the dielectric material 6 made of foamed plastic of the first embodiment is used as a spacer, and one film sheet is stacked on top of another film sheet as shown in FIG. This air cap sheet 6a has a height of approximately 2 mm and is made up of a number of air-closed caps formed independently using a film sheet.
A is interposed as a spacer between the radiation circuit board 1 and the feeder circuit board 1 and between the feeder circuit board 4 and the ground conductor board 5, as shown in FIG.

Here, the configuration of the feeder circuit board 4 is based on the configuration of the embodiment], and the radiation circuit board 1 has a square hole for linearly polarized waves of 14 mm on a side as an aperture 2 with a thickness of 0.4 mm, as shown in FIG. The antenna was punched out of a metal plate such as aluminum, and it was confirmed that the gain as a flat antenna was improved by 0.7 dB, making it even more effective.

In each of the above embodiments, the radiating element of the radiating circuit board 1 is formed by the aperture 2, but it may also be formed by an annular slot. In this case, as in the above embodiments, unnecessary mutual coupling can be minimized, and Loss can also be improved.

[Effects of the Invention] In a planar antenna consisting of a ground conductor, a feeding circuit, and a radiation circuit, the present invention improves the line width of the feeding line located near the coupling portion of the feeding circuit that electromagnetically couples with the radiating element of the radiation circuit. Since the line width is thinner than that of other feed lines, unnecessary mutual coupling can be minimized and transmission loss can be improved, and as a result, the flat antenna can be applied not only to reception of broadcasting satellites but also to reception of communication satellites. Furthermore, since transmission loss can be improved, antennas for broadcasting satellites can be made smaller and have higher performance than conventional antennas.

[Brief explanation of drawings]

FIG. 1 is a partially omitted exploded perspective view of Embodiment 1 of the present invention;
Fig. 2 is a partially omitted cross-sectional view of the same as above, Fig. 3 is an explanatory diagram of the pattern of the same as the above power supply circuit, Figs. 7(a) and 7(b) are explanatory diagrams of another example of the aperture, FIG. 8 is a sectional view of an air cap sheet used in Example 2 of the present invention, and FIG. The figure is an exploded perspective view of the same as above, with some parts omitted. 1 is a radiation circuit board, 2 is an aperture, 3 is a patch element, 4
4 is a power supply circuit board, 4a is a coupling portion, 4b and 4c are power supply lines, and 5 is a ground conductor plate. Agent Patent Attorney Ishi 1) Chief Figure 7 2

Claims (1)

[Claims] (1) In a planar antenna consisting of a ground conductor, a feeding circuit, and a radiating circuit, the line width of the feeding line located near the coupling part of the feeding circuit that electromagnetically couples with the radiating element of the radiating circuit is A planar antenna characterized by having a line width thinner than that of .