JPS61157105A - Antenna system - Google Patents

Abstract

PURPOSE:To eliminate the need for adjustment of an elevating angle and also for a circularly-linearly polarized wave converting section and a waveguide-coaxial converting section and to attain low cost by using a parabolic columnar reflecting mirror whose focus is located on a straight line at a right angle to ground and providing a primary radiator having a directivity in the oblique direction on the focus. CONSTITUTION:The parabolic columnar reflecting mirror is formed as a cylindrical parabola, and its focus 16 is a point in the horizontal direction and a straight lineiin the vertical direction The primary radiator 14 is arranged on the focus 16 in the vertical direction. In the radiator 14, a metallic plate 20 being an earth face on the rear side of a dielectric base 18 is provided and a microstrip line antenna element 22 is placed on the same straight line through series arrangement on the surface. Further, the elements 22 are arranged to a feeding phase difference to the elements 22 in response to an incoming radio wave at a reception district to receive a radio wave incoming with an elevating angle to a broadcast satellite depending on the installing location of the antenna device in an excellent way. The primary radiator 14 converts a radio wave reflected and converged by the reflecting mirror as a left rotary circularly polarized wave into a linearly polarized wave, which is converted into a high frequency current and fed to a converter 24.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an antenna device, and particularly to an antenna device for receiving microwave band signals, such as satellite broadcasting signals.

<Prior Art> Conventionally, the above-mentioned antenna device for receiving satellite broadcasting includes one as shown in FIG. 8, for example. In the figure, reference numeral 2 denotes an offset parabolic reflecting mirror, and a primary radiator 4 is placed at the focal point of this reflecting mirror 2. This -order radiator 4 is
Antenna horn section, circular-linear polarization conversion section, and waveguide
It consists of a coaxial conversion section. A converter 6 is coupled to this -order radiator 4 . - secondary radiator 4 and converter 6;
is attached to the reflector 2 by the arm 8, and the reflector 2
is supported by struts 10.

Radio waves transmitted from a broadcasting satellite are reflected by a reflecting mirror 2 and supplied to a converter 6 via a -order radiator 4 .

<Problems to be Solved by the Invention> However, since the above antenna device uses the reflecting mirror 2 or a paraboloid of revolution, it is difficult to receive satellite broadcasting well with only one focal point. However, there was a problem in that the elevation angle and azimuth angle of the reflecting mirror 2 had to be adjusted. Further, it has to be installed outdoors and needs to be supported by a support column 10, resulting in a problem that the scale of the device becomes large. Furthermore, since the antenna is installed outdoors and facing in the elevation direction, snow tends to accumulate on the reflector 2 and the primary radiator 4 in the winter, making it difficult to receive satellite broadcasts satisfactorily. Furthermore, since the -order sheet radiator 4 consists of a horn section, a circular-to-linear polarization conversion section, and a waveguide-to-coaxial conversion section, there are problems in that the configuration is complicated and the price is high. .゛It is an object of the present invention to provide an antenna device that solves each of the above-mentioned problems.

Means for Solving the Problems> Means for solving the above problems are either to be equipped with a reflector and a primary radiator like the conventional ones, or to have a reflector with a parabolic cylindrical surface. The -order radiator is a microsloth l-IJ tube array antenna that has diagonal directivity by arranging multiple radiating elements in a straight line and giving a phase difference in feeding to each of the radiating elements. This is located on the focal axis of the reflector.

According to the above means, since the reflecting mirror in the vertical direction consists of a parabolic cylindrical surface, its focal point becomes a straight line extending in a direction perpendicular to the earth. Since a primary radiator having diagonal directivity is arranged on this focal axis, when receiving satellite broadcasting at 1g, it is not necessary to adjust the elevation angle, and only the azimuth angle is adjusted. Furthermore, since the -order radiator is composed of a microstrip array antenna, a circular-to-linear polarization converter and a waveguide-to-11Ql+ converter are not necessary.

<Example> This example uses a parabolic cylindrical reflector 12 as shown in FIG.
and a primary radiator 14. This reflecting mirror 12 has a shape obtained by moving a horizontally arranged parabola in the vertical direction. That is, the reflecting mirror 12 is formed into a so-called cylindrical parabola. Therefore, the focal point 16 of this reflecting mirror 12 becomes a point in the horizontal direction as shown in FIG. 2, but becomes a straight line in the vertical direction as shown in FIG.

A primary radiator 14 is arranged vertically above this focus 16. This -order radiator 14 is shown in FIGS.
As shown in the figure, a metal plate 20 serving as a ground plane is provided on the back surface of the dielectric substrate 18, and five microstrip line antenna elements 22 are arranged in series on the same straight line on the surface of the dielectric substrate 18. This is what I did.

Each antenna element 22 converts the inverted left-handed circularly polarized wave into a linearly polarized wave because when the right-handed circularly polarized radio wave from the broadcasting satellite is reflected by the reflector 12, it is inverted to left-handed circularly polarized wave. It is said to have a shape that transforms. In addition, since the elevation angle with respect to the broadcasting satellite in I1 is approximately 30° at the northern tip of Hokkaido and approximately 50° at the southern tip of Okinawa, the broadcasting satellite can be used within the elevation angle range of 30° to 50' depending on the installation location of this antenna device. In order to receive well the radio waves arriving from the elevation angle, each antenna element 22 is
Each antenna element 221 is arranged so as to provide a feeding phase difference therebetween. Further, as shown by the dotted line a in FIG. 3, the -th order radiator 14 is positioned somewhat lower than the reflector 12 so that the radio waves arriving at the upper end of the reflector 12 also reach the i-th order radiator 14. It is arranged so that The antenna element 22 located at the top is terminated via a dummy resistor (not shown in the figure), and the antenna element 22 located at the bottom is terminated via a direct converter 24. is connected to the input of In other words, the lowest antenna element 22 is the feeding point. The reason why the lowest antenna element 22 is set as the feeding point is that blocking does not occur. Note that the antenna element 22 may be configured as shown in FIG. 6, and the converter 24 may be connected to the antenna element located in the center.

In this way, the impedance-matched high-frequency current can be output directly from the primary radiator, and the converter 2
4 can be easily connected. In this case, it is necessary to terminate the uppermost and lowermost antenna elements via dummy resistors. Converter 24 is attached to reflector 12 by support arm 26 .

As shown in FIG. 7, the antenna device constructed in this manner is installed at the eaves of a house or the like so that the primary radiator 14 is perpendicular to the ground. Then, the reflecting mirror 12 is adjusted to an azimuth depending on the installation location.

In this antenna device, radio waves from a broadcasting satellite are reflected by a reflecting mirror 12 as shown by dotted lines in FIGS.
focused on. The -order radiator 14 converts the radio wave reflected and focused by the reflecting mirror into a nine-left circularly polarized wave into a linearly polarized wave, and supplies the linearly polarized wave to a high frequency current to the annular converter 24 .

In the above embodiment, the microstrip line antenna element 22 is provided on the dielectric substrate 18 to constitute the primary radiator 14, or instead, a resonant element formed by an open planar circuit such as a circular or rectangular shape is used as the radiating element. It is also possible to use a microstrip antenna or a microstriped slot antenna. Further, in the above embodiment, the converter 24 is attached directly to the -order radiator 14, but if the feeder line is arranged so that blocking does not occur, it is not necessary to attach the converter 24 directly to the primary radiator 14. . Further, although this antenna device originally makes it unnecessary to adjust the directivity in the elevation angle direction, if a slight adjustment is desired, the primary radiator 14 may be tilted slightly within a range that does not significantly change the phase.

Effect> This invention uses a parabolic cylindrical reflector whose focal point is located on a straight line perpendicular to the ground, and a primary radiator with diagonal directivity is provided on the focal point. Therefore, only the azimuth angle needs to be adjusted. Moreover, it can therefore be installed at the eaves of a house, the auxiliary members required for installation can be simplified, and the size can be reduced. Furthermore, since it can be installed at the eaves of a house, etc., and the reflecting mirror is formed into a parabolic column, that is, a cylindrical parabola, satellite broadcasting can be received well even when snow is falling. Further, since the -order radiator is composed of a microstrip array antenna and can be directly fed with power, there is no need for a circular-to-linear polarization conversion section or a waveguide-to-coaxial conversion section, and therefore it can be manufactured at low cost.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an embodiment of the antenna device according to the present invention, Fig. 2 is a plan view of the embodiment, Fig. 3 is a vertical side view of the embodiment, and Fig. 4 is a primary antenna used in the embodiment. A front view of the radiator, FIG. 5 is a bottom view of the primary radiator used in the same example, and FIG. 6 is a front view of another example of the primary radiator used in the same example.
FIG. 7 is a perspective view showing the attached state of the same embodiment, and FIG. 8 is a perspective view showing an example of a conventional antenna device. 12...Reflector, 14...-order radiator. Patent Applicant: Diex Antenna Co., Ltd. Japan Broadcasting Corporation Representative: Satoshi Shimizu Haka2 ``kA1 Figure 1 Figure 3 Figure 4 Congee 5014 ``it'i6 Figure

Claims (1)

[Claims] 1) A primary radiator consisting of a microstrip array antenna in which a plurality of radiating elements are arranged in a straight line and has directivity in an oblique direction by giving a phase difference in feeding to each of the radiating elements is arranged on a parabolic cylindrical surface. Antenna device arranged on the focal axis of a reflecting mirror consisting of.