JPS5895272A - Controlling device for antenna directivity - Google Patents

Abstract

PURPOSE:To precisely control antenna directivity even if a beacon station stops to transmit by storing beacon wave tracking information to use it when said information is reduced. CONSTITUTION:A beacon wave summing signal received from a prescribed direction by the primary radiators 3, 3 which are located on symmetrical positions about the pattern focus F of a main reflector 1 is applied to a received field strength discriminator 10, and when the value of the summing signal is more than the threshold, an output from a synchronous detector 5 is applied to a main reflector driving means 2 through a changeover switch 12 and stored in a storing element 11. When the value of the beacon information summing signal is reduced less than the threshold, the switch 12 is turned through the discriminator 10 and the stored contents of the element 11 are applied to the means 2. Thus even if a beacon station stops to transmit, antenna directivity can be precisely controlled without the mistake of noise signals or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that correctly controls the pointing direction of an antenna in a desired direction.

Conventional directivity direction control devices use a number of primary radiators, calculate the difference in electric fields received from the second direction, and control the direction of the mirror surface so that the difference becomes O. is under control. This can be explained with reference to FIG. 1 as follows. 1. First, a beacon wave comes from a desired direction 8 and is transmitted to two primary radiators 3 (A,
B) Receive from VLc and add to the hybrid/de circuit 4 to obtain a sum signal A+B and a difference signal A-B. Figure 2 tbl
As shown in , the sum signal A+B has a maximum value at θ=0 and is an even function with respect to θ. On the other hand, the difference signal AB is an odd function with respect to θ, and is O at θ−〇. The difference signal passes through an AGC amplifier 9 which normalizes the amplitude using the sum signal, and is synchronously detected by a highly sensitive synchronous detector 5 using the sum signal as a local oscillation signal. The output is added to the drive mechanism 2, and the difference signal A-
By controlling the direction of the mirror surface so that B becomes 0, that is, θ becomes O, the pointing direction is controlled in a desired direction.

However, in this configuration, if the beacon wave is interrupted due to rain or the like, both the difference signal and the sum signal will be O regardless of θ, and the antenna directivity direction will be dominated by the axis, making it impossible to restrict the VC in a constant direction. Therefore, if this device is applied to a satellite-mounted antenna whose pointing direction must be controlled due to changes in the satellite's attitude, for example, it will not only make communications inoperable, but also lead to the destruction of the antenna drive mechanism in some cases. Sometimes.

In order to eliminate these drawbacks, the present invention stores antenna orientation control information in a storage element at all times, and when the electric field strength of an incoming beacon wave falls below a predetermined threshold or threshold value, An object of the present invention is to provide an antenna pointing direction control device that controls one drive mechanism of an antenna using stored information or data processing results.

The present invention will be explained in detail below with reference to the drawings.

FIG. 3 shows an embodiment of the present invention that can cope with a short-term drop in beacon level due to rain or the like. That is, t sum signal A
+B is added to the receiving electric field strength discriminator lO, and when the received electric field strength is greater than a predetermined value, the output of the J4/[ waver 5 is switched, and the switch goes up to the channel 2 and connects to the main reflector drive mechanism 2. At the same time, the output signal is stored in the storage element 11. When the received electric field strength becomes smaller than a predetermined value, the changeover switch 12 disconnects the output of the synchronous detector 5 from the main reflector drive mechanism 2 and the memory element 11, and transfers the output of the memory element 11 to the main reflector drive mechanism 2. By connecting, the antenna pointing direction is maintained before the beacon signal level drops below the threshold value.

The reception level of the beacon signal decreases due to rain within a few minutes at most, and the attitude of the satellite during this time can be ignored. According to actual measurements, the amount of attitude fluctuation of the satellite is about 0.010 per day. Therefore, with the configuration shown in FIG. 3, the pointing direction can be controlled correctly even if the receiving level of the beacon signal decreases for a short time due to rain or the like or the line is disconnected.

FIG. 4 shows the structure of an embodiment that corresponds to a case where the level of the beacon signal decreases or the signal is cut off for a long period due to a failure of the beacon transmitting station or the like. That is, the storage element 11VC in FIG. 3 is further connected to the processor 13.

The pointing direction of the satellite antenna changes due to changes in the attitude of the satellite itself, thermal distortion of the antenna, etc. However, at intervals of about one week, this fluctuation is a combination of fluctuations in the negative direction and periodic fluctuations on a daily basis, and can be predicted over a one-week period. Therefore, the fluctuation state of the pointing direction, that is, the output 5 of the synchronous detector, is approximated by a polynomial or an appropriate function with respect to time using the memory element 11 and the processor 13, and its coefficients or parameters are calculated using the latest data. You can decide while you are at it. If the beacon level drops, the drive mechanism 12 is activated.

It is controlled by data created by the processor 13 based on a polynomial or function approximation for time having coefficients or .zeta. parameters that have been constantly updated since 13Vc. As mentioned above, the fluctuation situation of the orientation direction can be predicted for about one week.

Therefore, with this configuration, even if the beacon station stops transmitting for about a week, the pointing direction can be controlled correctly.

[Brief explanation of drawings]

Fig. 1 is a side view of the configuration of a conventional pointing J direction control device, Fig. 2 is a characteristic diagram for explaining the principle of its operation, and Figs. 3 and 4 are diagrams showing an embodiment of the device of the present invention. It is a diagram. . 1... Main reflecting mirror, 2... Main reflecting mirror drive mechanism, 3
...-Next radiator, A, B...3, 2i1δ shown
Symbols to distinguish the primary radiators of 1, 4...
・Ibrid circuit, 5... Synchronous detector, 6.
...Sub-reflector, 7...Main radiation direction, 8...
Required pointing direction (direction of arrival of peacon wave), 9...A
GC amplifier, 10... Received electric field strength discriminator, 11
...Memory element, 12...Selector switch, 13...
・Processor, F...Focus of main reflecting mirror, θ...
・The angle between the main radiation direction and the required directivity direction (peakon wave arrival direction). Patent applicant: Nippon Telegraph and Telephone Public Corporation Agent: Tsune Hakumizu, 1 other person, 1st person: Kanriki 2: η 3: 1: η 4 ■

Claims (1)

[Claims] a memory element for temporarily storing beacon wave tracking data or the results of data processing of the beacon wave tracking data;
The present invention is characterized by comprising a mechanism for correctly controlling the antenna pointing direction using the information in the storage element or the result of data processing of that information when the beacon wave level falls below a predetermined threshold value. Antenna pointing direction control device.