JPH0429402A - Plane antenna for satellite broadcast reception - Google Patents

Abstract

PURPOSE:To offer a wideband plane antenna with the same cross polarization characteristic and input VSWR as that of a parabolic antenna by using a feed horn used in the parabolic antenna by miniaturizing as the unit reception element of the plane antenna. CONSTITUTION:A large number of feed horns 1 are mounted by arranging at the outside box 10 of the plane antenna as the unit reception elements of the antenna, and the oscillation probe 5 of each feed horn 1 is connected to a connection line 11 so as to keep an equal distance from the feed point A of the plane antenna, and a voltage induced on the oscillation probe 5 of each unit reception element is fetched in the feed point A so as to be set in-phase, and it is drawn out to the outside from the feed point A on the connection line 11, which is set as the reception signal of the plane antenna.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a receiving antenna device for satellite broadcasting.

In recent years, parabolic antennas and planar antennas have been developed as receiving antennas for satellite broadcasting, and microstrip antennas, slot antennas, and the like have also been developed as planar antennas.

[Conventional technology]

Conventional parabolic antennas have the advantage of being able to collect electromagnetic waves efficiently, have a wide receivable frequency band, and have little loss, but they require high precision in the mirror surface of the reflector, making manufacturing costs high. There are problems such as the installation space is large, snow tends to stick to the reflector and feed horn (snow builds up, and the reception condition worsens), and conventional microstrip antennas, slot antennas, etc. Planar antennas have the advantage that there are fewer restrictions on the installation location and are less prone to snow buildup, but both cross-polarization characteristics and input VSWR have narrow bands, and losses in the N'lA path feeding the antenna element There was a problem with the large amount of

[Problem to be solved by the invention]

By using a feed horn as a unit receiving element of a planar antenna, the present invention improves cross-polarization characteristics, human power VS.
The purpose is to provide a wideband planar antenna for both WR and WR.

[Means to solve the problem]

As shown in FIGS. 1 and 2, one end of a waveguide 3 having two orthogonal electromagnetic wave modes with different internal wavelengths is a horn-shaped primary radiator 2, and the other end of the waveguide is a terminal surface. 6
and a shorting plate 4, and an excitation probe 5 is provided in the middle of the waveguide.
A large number of feed horns 1 are installed in a row, and the electromagnetic waves of the satellite broadcasting signal incident on the primary radiator 2 are efficiently collected and guided to the waveguide 3, and the circularly polarized waves incident on the waveguide 3 are by converting the electromagnetic waves into linearly polarized electromagnetic waves, coupling the same linearly polarized electromagnetic waves to the excitation probe 5, and reflecting the electromagnetic waves at the termination surface 6 and the shorting plate 4. The impedances are matched, and the voltage induced in the co-excitation probe 5 is taken out as the output of the unit receiving element, and each unit receiving element is connected and the output is taken out as a reception signal of the antenna.

[Effect]

As explained above, the present invention uses the feed horn used in parabolic antennas as a unit receiving element of a planar antenna in a smaller size. Cross polarization characteristics, input VSW from the receiving element
Both R can be used as broadband planar antennas.

【Example〕

FIG. 1 is a front view seen from the opening of a feed horn showing an embodiment of the present invention. 1 is a feed horn, and the feed horn 1 is designed to generate two orthogonal electromagnetic wave modes with different pipe wavelengths. The opening of the waveguide 3 is formed into a substantially elliptical shape having a major axis (y) and a minor axis (g).

The primary radiator 2 is formed by forming one end of the waveguide 3 into a horn shape.
The electromagnetic waves of the satellite broadcasting signal incident on the primary radiator 2 are efficiently collected and guided to the waveguide 3.

In Figure 1, if the vertical direction is the Y axis and the horizontal direction is the X axis, the circularly polarized electromagnetic wave incident on the waveguide 3 is divided into an electric field component Y1 in the X axis direction and an electric field component X1 in the X axis direction. , and Yl and Xl are out of phase by 90 degrees. The horizontal minor axis of the opening of the waveguide 3 is X, and the vertical major axis is y, and the internal wavelength of the electromagnetic wave propagating inside the waveguide 3 is structurally the internal wavelength of the electric field component X1. The wavelength can be made shorter than the wavelength within the tube of Y, and the frequency does not change. The propagation speed in the tube is slower for electric field component X1, and at a position where the phase difference between Y and 5, and the angle of installation is Yl and Xl.
It is made to form an angle of 45 degrees with respect to the Y axis and the X axis in order to match the direction of the resultant vector.

FIG. 2 is a side view of a feed horn showing an embodiment of the present invention, in which the excitation probe 5 is attached at a position a length Zl in the longitudinal direction of the waveguide 3 from the opening of the waveguide 3. The length of this ZI is made to match the length at which a circularly polarized wave incident on the waveguide 3 is converted into a linearly polarized wave.

Furthermore, in order to attach the excitation probe 5, the terminal surface 6 is provided at a position zzl in the longitudinal direction from the position, and the short-circuit plate 6 is attached to the terminal surface 6 so that the tip of the short-circuit plate 4 is located at a position (i) away from the position. 4, the terminal surface 6 reflects electromagnetic waves with longer wavelengths in the tube, and the shorting plate 4 reflects electromagnetic waves with shorter wavelengths in the tube, thereby matching the impedance to the excitation probe 5. The voltage induced in the same excitation probe 5 is made to be large.

The shorting plate 4 should be made of metal, and should be as thin as possible if it has mechanical strength.An excitation probe extraction part 8 is provided on the side of the waveguide 3, and the excitation probe 5 is connected to the excitation probe extraction part. It is supported by an excitation probe support member 7 provided inside the waveguide 8 and drawn out to the outside of the waveguide 3.

FIG. 3 is a front view of a receiving section of a planar antenna showing an embodiment of the present invention, and FIG. 4 is a cutaway side view of the same planar antenna, in which the feed horn 1 is used as a unit receiving element of the antenna, and the outer box of the planar antenna is A large number of them are installed side by side in 10,
The excitation probes 5 of each feed horn 1 are connected by a connection line 11 so as to be equidistant from the feed point A of the planar antenna, and the voltages induced in the excitation probes 5 of each unit receiving element are in the same phase at the feed point. The signal is taken out from the feeding point A, and is led out from the feeding point A via a connecting line 11 to serve as a reception signal for the planar antenna.

In Fig. 1, if you want to receive counter-rotating circularly polarized waves, move the excitation probe 5 to the opposite side to the vertical Y-axis and make an angle of 45 degrees with the Y-axis. They may be attached as shown in FIG. 3 to form a unit receiving element, and then connected side by side as shown in FIG. In this case, the unit receiving element is attached so that its major axis is different from that shown in FIG. 3 by 90 degrees.

〔Effect of the invention〕

As explained above, according to the present invention, the feed horn used in a parabolic antenna is used in a smaller size as a unit receiving element of a planar antenna, and the cross-polarization characteristics and input VSWR are comparable to those of a parabolic antenna. Both can provide a wideband planar antenna, have fewer restrictions on installation locations than parabolic antennas, and are less prone to snow buildup, greatly contributing to improving the performance of satellite broadcast receiving antennas.

[Brief explanation of the drawing]

FIG. 1 is a front view seen from the opening of a feed horn showing an embodiment of the present invention, FIG. 2 is a side view of the same feed horn, and FIG. 3 is a receiving section of a planar antenna showing an embodiment of the present invention. FIG. 4 is a cutaway side view of the same planar antenna. 1--Feed horn, 2--Primary radiator, 3 Waveguide, 4- Shorting plate, 5- Excitation probe, 6
- Termination surface, 7 - excitation probe support material, 8 excitation probe drawer part, 10 - flat antenna outer box, 1
1- Connection line.

Claims (1)

[Claims] One end of the waveguide, which has two orthogonal electromagnetic wave modes with different guide wavelengths, is used as a horn-shaped primary radiator, and the other end of the waveguide is provided with a termination surface and a short-circuit plate. A large number of feed horns equipped with excitation probes are installed in a row in order to efficiently collect the electromagnetic waves of the satellite broadcasting signal incident on the primary radiator, guide them to the waveguide, and generate circularly polarized waves incident on the waveguide. converting the electromagnetic waves into linearly polarized electromagnetic waves, coupling the same linearly polarized electromagnetic waves to the excitation probe, and matching the impedance to the excitation probe by reflecting the electromagnetic waves at the termination surface and the shorting plate. A planar antenna for receiving satellite broadcasting, characterized in that the voltage induced in the coexcitation probe is extracted and used as an output of a unit receiving element, and each unit receiving element is connected to take out the output and used as a received signal.