JPS6256880A - Antenna directivity detection system - Google Patents

Abstract

PURPOSE:To improve the operating rate of a circuit while maintaining its reliability by performing control so that a signal for directivity detection is transmitted from one of plural ground stations by switching ground stations. CONSTITUTION:Signals for directivity detection transmitted by the ground stations 2a and 2b are supplied to a tracking receiver 5a through feeding circuits 4a and 4b and a signal synthesizing circuit 9. Then, the signal for directivity detection is sent from one ground station, e.g. 2a and processed by the receiver 5a to detect an error in antenna directivity. At this time, if the signal from the ground station 2a is broken owing to a rainfall, etc., the transmitting station for directivity error detection is switched to the ground station 2b. When the ground stations 2a and 2b are at some distance, the probability that signals circuits for directivity detection are both broken is extremely small, so the operation rate is improved.

Description

[Detailed Description of the Invention] 7 [Field of Industrial Application] The present invention provides an antenna system based on a beacon signal from a ground station that is used to direct an antenna mounted on an artificial satellite to a desired direction on the ground with high precision. This invention relates to an antenna pointing direction error detection method for detecting pointing errors.

[Conventional technology and problems]

Conventionally, this type of system has been constructed by providing one ground station and one system of feeding horn and feeding circuit for detecting pointing direction error of the satellite-mounted antenna facing the ground station.

However, at frequencies higher than the microwave band, the pointing error detection signal (beacon signal) may be attenuated by rain, etc., and the beacon line may be disconnected. In such cases, the antenna pointing error increases. However, there was a problem in that the operating rate of the entire satellite deteriorated.

On the other hand, with a similar configuration, two ground stations are installed,
Furthermore, there are systems disclosed in Taitomo Sho No. 55-7422i and Japanese Patent Application No. Sho 59-197793, which adopt a system configuration including two pointing direction detection systems mounted on a satellite.

The configuration in this case is characteristically shown in PIS 1 diagram.

In Fig. 1, 1 is the earth, 2a and 2b are ground stations, 3 is a satellite-mounted antenna mirror surface, 4a and 4b are feeding horns and feeding circuits, 5a and 5b are tracking receivers, and 6a and 6b are antenna pointing error output signals. , 7 is a satellite yaw angle calculation circuit, and 8 is a yaw angle signal. The configuration shown in this figure is used to obtain the rotation angle of the satellite's yaw angle from the directions of two ground stations. .

In such a configuration, when controlling the antenna pointing direction using the output (for example, the antenna pointing error output signal 6a) of the antenna pointing error detection system consisting of the antenna feeding circuit and the tracking receiver, this system If the beacon signal line of one antenna is disconnected, it is possible to control the antenna pointing direction using the other antenna pointing error output signal 6b.

However, in this case, if one of the tracking receivers breaks down, it cannot be repaired at the satellite, so there is a drawback that it is not possible to remedy the deterioration of the communication line operating rate. Therefore, in order to improve the inclination of the device, it is necessary to provide a redundant system for the tracking receivers of both 1j, which increases the weight of the entire device by 2 + -1. was there.

[Purpose of the invention]

An object of the present invention is to provide a pointing direction detection method for an antenna mounted on a satellite, which can improve the line operation rate while maintaining the reliability of the device, and which can be realized with a simple configuration. There is.

[Means for solving the problem, α]

According to the present invention, the above object is achieved by the means described in the claims.

That is, in the present invention, a plurality of ground stations are installed,
The satellite has a corresponding feeding circuit for antenna pointing error inspection, and by combining the outputs of multiple feeding circuits and guiding them to the tracking receiver, one tracking receiver processes signals from two stations in each location. The main feature is to avoid disconnections by switching between ground stations.

In the conventional technology, since there is only one ground station, there is no remedy if the beacon line is disconnected, and even if multiple ground stations and antenna feeding circuits are installed, the tracking receiver However, the present invention is superior to conventional technology in that it is possible to realize a highly reliable device with a simple configuration in which signals from multiple ground stations are processed by a single tracking receiver. This is different from et al.

〔Example〕

The plS2 diagram is a diagram explaining the configuration of a system according to an embodiment of the present invention, and shows a case where there are two ground stations.
is the earth, 2a and 2b are the ground stations, 3 is the satellite antenna mirror surface, 4a and 4b are the feeding horn and feeding circuit for antenna pointing error detection (however, it may also be used for communication), (-(kI- ): Own H$, WkmG, CL1 ``P''
9 represents a signal switching circuit.

In FIG. 2, pointing direction detection signals transmitted from ground stations 2a and 2b are supplied to a tracking receiver 5a through feeder circuits ta and 4b and a signal synthesis circuit 9, respectively.

Then, a pointing direction detection signal is transmitted from one of the ground stations, for example 2a, and the signal is processed by the tracking receiver 8!5a to detect the antenna pointing error.

At this time, if signal No. 15 from the ground station 2a is cut off due to rain or the like, the transmitting station for pointing error detection is switched to the ground station 2b. At this time, if the distance between the ground stations 2a and 2b is a certain distance, there is a very low probability that both pointing error detection signal lines will be disconnected, so the operating rate will be greatly improved.

Furthermore, when a so-called hybrid circuit is used as the signal synthesis circuit, two outputs are obtained, so one output is supplied to the tracking receiver 8!5a, and the other output is supplied to the tracking receiver fi5b. This makes it possible to create a redundant configuration with the pre-punishment tracking receiver ff1815b added, without adding a special circuit such as a C switching circuit, and improve the reliability of the device.

For example, V in the configuration of fiS1 diagram, which is one of the conventional techniques.
At position C, four tracking receivers are required to obtain the same reliability as in Fig. 2, but in this embodiment, only two are required as shown in Fig. 2.

When performing two-dimensional tracking, the monopulse tracking system feeder circuit output normally consists of three signals: a reference signal, and one two-dimensional (for example, east-west, north-south) error signal. However, in the case of the high-order mode detection monopulse tracking method, there is a case where there is only one error signal, and this is a signal equivalent to the two-dimensional error signals synthesized with a phase difference of 90°.

On the other hand, there are various configurations of tracking receivers and power supply circuits.
[“New Edition Satellite Communication Engineering” Kanken-1L Lattice Publishing, 1
As stated in J. 1969, there are three channel systems, two channel systems, and one channel system.

The 3-channel system is equipped with a high frequency amplifier, a frequency converter, an intermediate frequency amplifier, an AGC amplifier, etc. for 3 channels for the 3 signals of the reference signal and the 2 error signal, and uses the reference signal to normalize the amplitude of the error sign. AGC is applied to detect each error signal using the phase of the reference signal as a reference to obtain angular error DC output signals in the east-west and north-south directions.

In the 2-channel system, two error signals are orthogonally synthesized with a 90° phase difference, or by periodically switching the error signal system to one channel, the error signal system is converted to a single channel, and the signal is connected to a high-frequency amplifier, a frequency converter, Intermediate frequency and AGC
This method uses an amplifier for two channels, a reference signal and an error signal, and the error signal is separated again in accordance with each two-dimensional error at the detection stage and output.

The 1-channel method combines or switches all three signals, including not only the error signal but also the reference signal, into one channel, and requires only one channel of high-frequency amplifiers, frequency converters, intermediate frequency and AGC amplifiers, etc. It is.

There are various methods for converting three signals into one channel. After orthogonally combining the two error signals, low-frequency phase modulation or amplitude modulation 17 is performed to combine them with the reference signal. A method of applying phase modulation or amplitude modulation to a frequency signal, then combining it with a reference signal,
There is a method in which both error signals are subjected to phase modulation with different amounts of phase shift, and then combined with a reference signal. There are methods such as a method of performing phase modulation or amplitude modulation and then combining it with a reference signal, and a method of switching between three signals with a switch and outputting only one signal.

Therefore, as mentioned above, depending on the number of channels of the tracking receiver, there are various circuit configurations to make the feeder circuit either 2 channels or 1 channel, and the outputs of the feeder circuits of two antenna systems are supplied to one tracking receiver. There are several possible ways to arrange the signal synthesis circuits for this purpose.

One is to have a signal synthesis circuit for each of the three signals, the reference signal of each system and the two-dimensional error signal, and combine the signals of the two systems, and the second is to combine or switch between the two difference signals. After converting the two signals into one channel by doing this, we have a signal synthesis circuit for the two signals, the reference signal and the error signal converted into one channel, and synthesize the two systems of signals. There is a method of combining three two-dimensional error signals into Q1 channels by combining or switching, and then using one signal combining circuit to perform signal combining of two systems.

〔Effect of the invention〕

As explained above, according to the present invention, a plurality of ground stations are provided for transmitting pointing error detection signals, and a feeding horn and a feeding circuit for the onboard antenna are provided corresponding to each of these ground stations. The system is structured so that the signals are supplied to one tracking receiver, and switching between ground stations avoids disconnection of the line, which greatly improves the operating rate of the line for detecting antenna pointing errors. It has the advantage of being able to

Further, according to the configuration of the present invention, the antenna pointing error detection device can be constructed with a simple configuration, and therefore, its reliability can be greatly improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a configuration in which two conventional pointing direction detection systems are provided, and FIG. 2 is a configuration diagram of a system according to an embodiment of the present invention. 1...Earth, 2a, 2b...Ground station for transmitting pointing direction detection signal, 3...Satellite antenna mirror surface, 4a, 4b...Antenna orientation Direction detection power supply horn and power supply circuit, 5a+5
b...Tracking receiver, 6a, 6b...
Antenna pointing error output signal, 7...Yaw angle calculation circuit, 8...Yaw angle signal, 9.
...Signal synthesis circuit

Claims (1)

[Claims] In addition to installing a plurality of ground stations that transmit signals for detecting the pointing direction, a feeding horn and a feeding circuit for detecting the pointing direction using a monopulse tracking method are installed on the antenna on the satellite facing the ground station, corresponding to each of the ground stations. The output signal of each feeder circuit is simultaneously supplied to one tracking receiver, and the signal from the ground station is processed by the tracking receiver, thereby obtaining a DC output corresponding to the antenna pointing error. An antenna pointing direction detection method characterized in that the ground station is switched so that a pointing direction detection signal is transmitted from any one of the plurality of ground stations.