JPS59131202A - Antenna device - Google Patents

Abstract

PURPOSE:To control the beam and to obtain a fixed surface of radio waves by controlling the feeding phase shift degrees to plural primary radiators in response to a reflector that is deformed by the sunbeam and based previously on the estimation of deformation of the period of a day, etc. CONSTITUTION:A parabolic reflector 1 is deformed by heat as shown in the figure 1' for instance, and therefore the surface of a radio wave is deformed. Therefore the phase shift degrees of phase shifters 9-1-9-n are controlled to compensate the deformation of the radio wave surface. As a result, the optical path of the radio wave is set in parallel to the original optical path 8 as shown in the figure 8''. Thus it is possible to prevent the bend of the optical path of the radio wave which is caused with a conventional antenna device.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an antenna device comprising a reflector and a primary radiator, and will be explained below using an antenna mounted on a geostationary satellite as an example.

Figure 1 is a diagram for explaining a conventional antenna device.
1) is the reflector, (2) is the reflector support, (3) is the -order radiator, (4) is the geostationary satellite body, (5) is the transmitter/receiver separator, (
6) is the transmitter, (7) is the receiver, (81//i shows the optical path of the radio wave.

In Fig. 1, the optical path (8) of the radiated radio waves from the primary radiator (3) placed at the focus of the parabolic reflector (1) is directed to the desired point on the earth as seen from the geostationary satellite orbit. Assume that the antenna is attached to a geostationary satellite. However, in reality, geostationary satellites revolve around the earth in line with the earth's rotation, so if the top of Figure 1 is facing north, the east side of the satellite will be in the morning, and the back of the satellite in the afternoon.

Sunlight hits the west side of the satellite in the evening, and the front of the satellite at night.
Additionally, as sunlight tilts north and south in spring, summer, autumn, and winter, the temperature distribution of the reflector changes as well, and the resulting thermal deformation of the reflector changes the optical path of radio waves.

The required point will not be irradiated correctly.

In other words, if we assume that the optical path (8) of the radio wave in Figure 1 is in the morning or evening of the vernal or autumnal equinox, the sunlight is shining from the side of the 2-reflector (1), so there is little thermal deformation, but it remains constant throughout the day. 1 reflector (1
) The temperature on the back surface of the antenna increased, causing the reflector to deform as shown in (1) in Figure 1, which deformed the wavefront of the radio wave and caused deterioration of the antenna characteristics.

Alternatively, the optical path (8) of the radio wave in Figure 1 curves southward as shown in (8).Similarly, in the middle of the night, sunlight hits the front of the 2 reflecting mirrors, so it is reflected (not shown in Figure 1). The mirror deforms to become shallower, and this deforms the wavefront of the radio waves, deteriorating the antenna characteristics and causing the optical path of the encased radio waves to curve northward.

However, this deformation changes regularly over a short period of time, with a daily cycle, and over a long time, with a one-year cycle, and can be predicted in advance.

Therefore, in the present invention, a modification is added to the primary radiator to compensate for the deformation of the wavefront of the radio wave due to this deformation, thereby preventing deterioration of the characteristics of the antenna and bending of the optical path of the radio wave.

This will be explained below with reference to two figures.

FIG. 2 shows an embodiment of the antenna device according to the present invention, in which (1) is a parabolic reflector, (2) is a support of the reflector, and (3-1) to (!In) are /161 to /1
n primary radiators of 6n, (4) is the geostationary satellite main body, (5
) is a transmitter/receiver separator, (6) is a transmitter, (7) is a receiver, (
8) is the optical path of radio waves.

(9-1) to (9-n) are n phase shifters of 41 to /16n.

0 [ is an n-distribution power divider, an is the above /16 i
Control signals as-i to as for controlling the amount of phase shift of n phase shifters (9-1) to (9-n) of ~/16n
-n Indicates a controller that outputs full output.

In Figure 2, there are n pieces of -order radiators (1~/I6n) (
For example, if the horn is located at the apex and center of a regular hexagon, n = 7), and n phase shifters from /161 to An are connected to the power divider On. .

Therefore, even if the reflecting mirror (1) is deformed by heat as shown in (1') for example, and the wavefront of the stain wave is deformed by this,
To compensate for this, phase shifters (q-1) to (9-n)
Adjust the phase shift amount to correct the deformation of the radio wave front. As a result, the optical path of the radio wave becomes parallel to the original optical path (8) as shown in (8) in Figure 2, and the bending of the optical path of the radio wave that occurs in conventional antenna devices can be prevented. can.

As mentioned earlier, in geostationary satellites, the thermal deformation of the reflector changes periodically due to changes in the direction of sunlight irradiation, and the amount of deformation can be predicted analytically, so information on this It is easy to control the amount of phase shift of the phase shifter using a controller αυ stored in advance so as to prevent deformation of the wavefront of the radio wave due to thermal deformation of the reflecting mirror.

As described above, by using the antenna device according to the present invention, it is possible to prevent the deterioration of the characteristics of the 99 reflector due to thermal deformation. 10 m), or when using a high circumference or a high number of wires. Although an example in which there is one reflecting mirror is shown here, it goes without saying that the same applies to a case in which two reflecting mirrors are used.

Further, although an example of an antenna mounted on a geostationary satellite is shown here, the present invention can be implemented in any antenna device whose thermal deformation can be predicted in advance.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a conventional antenna device, and FIG. 2 is a diagram showing an embodiment of the present invention! ll, (1) C reflector,
(2) is the pillar, (3) is the -order radiator, and (4) is the satellite body. (5) is a transmitter/receiver separator, (6) is a transmitter, (7) is a receiver, (8) is a radio wave optical path, (9) is a phase shifter, (II is a power divider, +11) is a phase shifter. This is the control circuit for the device. Note that the same or corresponding parts in FIG. 9 are designated by the same reference numerals. Agent Makoto Kuzuno

Claims (1)

[Claims] An antenna device comprising a reflecting mirror and a primary radiator, a plurality of primary radiators, a plurality of phase shifters provided corresponding to each of the plurality of primary radiators, and the phase shifter. a power divider that distributes power to each radiating element through the
An antenna device comprising: a controller that controls the amount of phase shift of each of the phase shifters to compensate for the curvature of a wavefront of a radio wave due to thermal deformation of a reflecting mirror, which is predicted in advance.