JPH10160776A - Method for measuring radiation pattern of antenna mounted on satellite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring the radiation pattern of an antenna mounted on a satellite on an orbit using a plurality of portable communication terminals on the ground. SOLUTION: Radiation pattern of a communication antenna 6 mounted on a satellite is measured using a plurality of ground communication units A1 -AN arranged in the communication region of a communication satellite 5. Signals of frequencies F1, F2$,v, FN are transmitted from the antenna of N ground communication units installed at various places and received by the communication antenna 6 mounted on the satellite. N signals thus received are divided through a frequency selection circuit 7 into signals of frequencies F1, F2,..., FN and the level of each signal is detected by a level detector 8 thus measuring the radiation pattern of the communication antenna mounted on the satellite.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring a satellite-mounted communication antenna pattern used for satellite mobile communication in which, for example, an antenna mounted on an artificial satellite and an antenna mounted on a portable terrestrial communication apparatus communicate. It is.

[0002]

2. Description of the Related Art The pattern of an antenna mounted on a satellite does not match the antenna pattern measured on the ground because the environment is significantly different between the ground and the satellite orbit. this is,
This is because the deformation due to gravity is large on the ground, and the thermal environment of the satellite in orbit cannot be accurately simulated on the ground.

[0003] Therefore, it is desirable for a satellite-mounted antenna (particularly, a large antenna for communication) to directly measure an antenna pattern in orbit. FIG. 4 shows a conventional antenna pattern measuring method for measuring the receiving sensitivity of an antenna mounted on a satellite in this way. In FIG. 4, reference numeral 1 denotes an antenna system of a terrestrial communication device (fixed base station), 2 denotes a transmission / reception shared antenna mounted on a satellite, 3 denotes a detector, 4 denotes a telemetry command antenna, and 5 denotes an artificial satellite.

Referring to FIG. 4, a conventional method for measuring a satellite-mounted antenna pattern will be described. In order to obtain the reception sensitivity of the transmitting / receiving antenna 2 mounted on the artificial satellite 5, the signal radiated by the terrestrial transmitting / receiving antenna system 1 is received by the transmitter / receiver antenna 2, and the received signal is detected by the detector 3. It is detected. The detected signal is converted by the detector 3 into signal data representing the magnitude of the receiving sensitivity. The signal data is sent to the terrestrial transmission / reception shared antenna system 1 by the telemetry command antenna 4, and the reception sensitivity is recognized on the ground. Since there are a plurality of terrestrial communication apparatuses (fixed base stations) and the satellite-mounted antenna is stationary with respect to the earth station by attitude control in a normal state, the reception sensitivity to the plurality of base stations is in the direction of the satellite-mounted antenna. Antenna sensitivity, that is, the antenna pattern.

When the number of base stations is not enough to measure the antenna pattern, a transmitting and receiving antenna is mounted on a movable truck or the like to increase the number of observation points, or when it is not possible (for example, in a mountain or sea). In this case, the above-mentioned measurement is performed by changing the direction of the satellite-borne antenna by controlling the attitude of the satellite, and the antenna sensitivity of the portion that cannot be measured by the fixed station measurement is measured.

In the above description, there is only one terrestrial transmission / reception shared antenna system 1, but the antenna pattern can be measured in the same manner when the antenna system is divided into two, one for transmission and one for reception. Further, in the description of the conventional example, a case has been described in which the transmission / reception shared antenna 2 mounted on the satellite is operated as a reception antenna to measure reception sensitivity.
Since the antenna has reciprocal characteristics of transmission and reception, the transmission / reception shared antenna 2 is operated as a transmission antenna, a signal is transmitted from the transmission / reception shared antenna 2 operated as the transmission antenna, and the ground transmission / reception shared antenna system 1 is transmitted.
, And the reception sensitivity may be measured.

[0007]

The above conventional antenna pattern measuring method has the following problems.
When the receiving sensitivity is measured using the transmitting / receiving antenna 2 mounted on the satellite for reception while the attitude of the satellite is in a stationary state, a large number of ground observation points are required and cannot be performed at the same time. There was such a drawback. That is, the antenna angle portion where the ground station does not exist must be moved around by mounting a measuring transceiver on a truck or the like, and the measurement becomes difficult especially when the antenna angle direction is mountainous or at sea. was there.

In addition, the performance of the detector is difficult to secure a sufficient performance under the limitation of being mounted on a satellite, and is easily affected by the space environment. There is also a problem. Also, in the future, if the satellite becomes larger and a 10m-class large antenna is applied as a satellite-borne antenna, it is assumed that the above large antenna will be divided into a transmitting antenna and a receiving antenna to reduce the influence of "passive intermodulation". Is done. here,
"Passive intermodulation" means that a signal leaks from a transmission system to a reception system on a satellite and enters the reception system, causing intermodulation in the reception system.

When the size of the antenna mounted on the satellite is increased, the beam width becomes narrower, so that the accuracy of the antenna pattern measurement is required. In particular, when precise on-orbit evaluation of the radiation pattern of the receiving antenna is required, there is a problem that the measurement of the radiation pattern becomes difficult.
Further, after the operation of the satellite communication when the service is actually started, the measurement of the antenna pattern for monitoring is inconvenient because the service is interrupted and performed.

In the conventional antenna pattern measuring method, the receiving sensitivity of the transmitting / receiving antenna 2 is measured.
Since the detector 3 and the telemetry command antenna 4 are required as hardware, there is a problem that the weight of the detector 3 and the telemetry command antenna 4 is inevitably increased as a device mounted on the satellite. The present invention has been made to solve the above problems, and does not require a detector 3 or a telemetry command antenna 4, and uses a plurality of communication terminals on the ground to orbit the satellite antenna 2 in orbit. It is an object of the present invention to provide a method for measuring a satellite-borne antenna pattern that can easily measure a radiation pattern of a satellite.

[0011]

SUMMARY OF THE INVENTION A method for measuring the pattern of a satellite-mounted antenna according to the present invention uses an antenna pattern of a communication antenna mounted on a satellite by using a plurality of terrestrial communication devices arranged in a communication area of a communication satellite. .., FN transmitted from the antennas of the N terrestrial communication devices by the communication antennas mounted on the satellites, respectively. Frequency signals by the frequency selection circuit.
, F2,..., FN signals, and the level of each signal is detected by a level detector to measure the radiation pattern of the communication antenna mounted on the satellite. Alternatively, conversely, signals of different frequencies F1, F2,..., FN are transmitted from the communication antenna mounted on the satellite to the receiving antennas of the N terrestrial communication devices. By receiving only the signal assigned to each terrestrial communication device by the frequency selection device corresponding to each frequency, and detecting the received signal level with a level detector, the radiation pattern of the communication antenna mounted on the satellite Is measured.

When detecting the level of each signal with a level detector, there is provided a level correction circuit for adding a variation of a level variation caused by a difference in each frequency, and a bias of the variation is applied to the detected level. In addition, the radiation pattern of the receiving antenna mounted on the satellite is measured. Still further, a method of measuring a pattern of a satellite-mounted antenna according to the present invention measures an antenna pattern of a communication antenna mounted on a satellite using a plurality of terrestrial communication devices arranged in a communication area of a communication satellite. , TN transmitted from the antennas of the N terrestrial communication devices at different times T1, T2,..., TN by the communication receiving antenna mounted on the satellite. , TN by a time switch corresponding to each of the above-mentioned times, and the level of each of the above-mentioned signals is detected by a level detector. It measures the pattern.

On the contrary, different times T1, T2,..., T
A signal having the same frequency is transmitted to N reception antennas of the N terrestrial communication devices, and each terrestrial communication device receives only the signal assigned to each terrestrial communication device by the time switch corresponding to each time. Then, the radiation pattern of the communication antenna mounted on the satellite is measured by detecting the received signal level with a level detector. Still further, in the method for measuring a pattern of a satellite-mounted antenna according to the present invention, the plurality of terrestrial communication devices are mobile phones, and the frequencies F1, F2,.
Is a terrestrial service area during operation of the satellite mobile communication service, and measures the radiation pattern of the communication antenna mounted on the satellite by measuring the reception electric field strength when each mobile phone is used after the operation of the satellite mobile communication service. Is what you do.

[0014]

FIG. 1 is a diagram showing an embodiment of the present invention. In FIG. 1, A1, A2,..., AN are terrestrial communication devices, 6 is a receiving antenna, 7 is a frequency selection circuit, 8
Is a level detection circuit. The terrestrial communication devices A1, A
2 ...., AN may be either fixed on the ground or movable like a mobile phone.

Next, a method of measuring a satellite antenna pattern according to the present invention will be described with reference to FIG. In FIG. 1, signals of frequencies F1, F2,..., FN are assigned to terrestrial communication devices A1, A2,.
The radiated power level is also substantially constant. The signals of the frequencies F1, F2,..., FN transmitted from the terrestrial communication devices A1, A2,..., AN having different transmission positions are received by the receiving antenna 6 provided in the artificial satellite 5. The receiving antenna 6 has the frequencies F1, F2,.
It has a reception frequency band including N. The received N signals are divided by the frequency selection circuit 7 into the frequency F
, FN,..., FN, and the level detector 8 detects the level of each of the signals. The signal level is sent to the ground via a downstream communication line.

.., FN is assumed to be 1 to 2 kHz. Also, this F1
The width of the band from FN to FN is determined by how many frequency selection circuits are provided in the satellite. However, considering ordinary S-band satellite mobile communication, F1 = 2500 kHz to FN = 2600 kHz (N = 101). A width is assumed. In this way, the signals of the terrestrial communication devices A1, A2,.
Receive the respective signal levels, in other words, if the satellite is stationary, measure the reception sensitivity, that is, the radiation pattern, at which the observation angle of the reception antenna 6 provided on the artificial satellite 5 is different. Will be.

In the operation test before the start of the satellite communication service, the above-mentioned radiation pattern is measured with a ground fixed base station or a mobile base station (for example, mounted on a car) as a measurement point. In the satellite communication, the frequency is changed for each zone. After the satellite communication service is operated, it is possible to measure the antenna-mounted antenna pattern by measuring the reception electric field strength of the mobile phone with which communication is actually being performed. In this case, the output of each mobile phone is small, and the transmission output also varies slightly. However, after the operation of the satellite communication service, the number of mobile phones used at all times is 10,000,
Since the number becomes as large as 100,000 and can be handled as a statistic, the measurement accuracy of the antenna pattern is sufficiently maintained. In addition, the method for measuring a satellite-mounted antenna pattern according to the present invention does not require any special operation for antenna pattern measurement. Therefore, the method for monitoring an antenna pattern after operation of a satellite communication service and, consequently, monitoring the communication state is not suitable. It is a very simple and convenient measurement method. Note that a simple portable terminal or a portable telephone itself may be used at the time of antenna pattern measurement during an operation test before the start of the satellite communication service. In this case, it is desirable to add a GPS device to the above-mentioned simplified portable terminal or portable telephone, and simultaneously transmit accurate positional information on the ground together with the received electric field strength.

FIG. 2 shows an embodiment in which a level correction circuit between frequencies is provided in the above radiation pattern measurement. In the radiation pattern measurement, the terrestrial communication devices A1, A2,.
The frequency characteristics of the radiation pattern of the AN antenna and the receiving antenna 6 are desirably flat at the frequencies F1, F2,..., FN. However, in an actual antenna, the radiation pattern varies depending on the frequency. A level correcting circuit 9 is provided as shown in FIG. The level correction circuit 9 stores a level value for correcting the variation, and the signal level detected by the level detector 8 is corrected based on the stored level value. The correction value is measured in advance on the ground.

Next, another embodiment of the present invention will be described with reference to FIG. In FIG. 3, reference numeral 10 denotes a time switch, and the terrestrial communication devices A1, A2,..., AN placed in various places emit signals at the same frequency F at different times T1, T2,. Are received by the receiving antenna 6 provided in the artificial satellite 5. The received N signals are divided into the T1, T2,..., And TN signals by the time switch 10 according to the time, and the level of each of the signals is detected by the level detector, so that the radiation of the receiving antenna 6 is performed. The pattern is measured.

Although the present invention has been described above, the measurement accuracy of the present invention depends on the performance of the terrestrial communication device.
Therefore, for example, it is necessary to calibrate the transmission power of the terrestrial communication devices A1, A2,. In the pattern measurement accuracy of the present invention, it is important to know the exact position of the terrestrial communication device. Therefore, in any case (for example, even when measuring an antenna pattern in an operation test before starting a satellite communication service). , And the GPS function are more preferably added to the terrestrial communication devices A1, A2,.

[0021]

According to the present invention, as described above, the communication between the communication antenna provided on the artificial satellite and the antennas of N terrestrial communication devices such as mobile phones existing on the ground is realized. The signals of frequencies F1, F2,..., FN transmitted from the antennas of the N terrestrial communication devices are received by the receiving antennas provided on the artificial satellite, and the received N signals are received by the frequency selection circuit by the frequency selection circuit. FN, F2,..., FN signals are detected by a level detector, and the level of the fluctuation amount is added to the detected level by a level correction circuit for adding a radiation pattern fluctuation amount due to a difference in frequency. By applying a bias or vice versa, different frequencies F1, F2,...
FN signals are transmitted toward the N receiving antennas of the terrestrial communication devices, and each of the terrestrial communication devices receives only the signal assigned to each terrestrial communication device by the frequency selection device adapted to each of the frequencies, The level of the received signal is detected by a level detector, and further, a bias of the variation is applied to the detected level by a level correction circuit that adds a variation amount of a radiation pattern due to a difference in frequency, so that the signal is mounted on the satellite. The radiation pattern of the communication antenna can be easily measured.

Also, signals of the same frequency transmitted at different times T1, T2,..., TN from the antennas of the N terrestrial communication devices are received by the receiving antennas provided in the artificial satellite, and are received. .., T by the time switch according to the time.
N, and the level of each signal is detected by a level detector, or conversely, from the communication antenna mounted on the satellite, different times T1, T
, TN, the signals of the same frequency transmitted to the TN are transmitted to the receiving antennas of the N terrestrial communication devices. By receiving only the assigned signal and detecting the received signal level with the level detector, the radiation pattern of the communication antenna mounted on the satellite can be easily measured.

Further, the radiation pattern of the receiving antenna provided on the artificial satellite can be easily measured without providing special ground equipment such as loading the ground on a truck or the like and moving it to various places and measuring the electric field strength. This has the effect. Furthermore, after the operation of the satellite communication service, the antenna-equipped antenna pattern can be measured by measuring the reception electric field strength of the mobile phone with which communication is actually performed, so that the fixed base station and other special equipment can be measured. The antenna pattern on the satellite can be measured at all times without using it for the purpose and without any special work for measuring the antenna pattern. This is advantageous in that a very simple and convenient measurement method can be provided for use in monitoring of the measurement.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a method of measuring a satellite-borne antenna pattern of the present invention.

FIG. 2 is a diagram showing an improved example of the embodiment of the present invention.

FIG. 3 is a diagram showing another embodiment of the method of measuring a satellite-borne antenna pattern of the present invention.

FIG. 4 is a diagram illustrating a conventional method for measuring a satellite-borne antenna pattern.

[Explanation of symbols]

 1 terrestrial transmission / reception shared antenna system 2 satellite-mounted transmission / reception shared antenna 3 detector 4 telemetry command antenna 5 artificial satellites A1, A2,. . . , AN Ground communication equipment 6 Receiving antenna 7 Frequency selection circuit 8 Level detector 9 Level correction circuit 10 Time switch

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masao Miyauchi 2-12-5 Iwamotocho, Chiyoda-ku, Tokyo Research Institute for Next Generation Satellite Communication and Broadcasting Systems Co., Ltd. (72) Inventor Yoichi Kawakami Chiyoda-ku, Tokyo 2-12-5 Iwamotocho Incorporated Research Institute for Next Generation Satellite Communications and Broadcasting Systems

Claims (6)

[Claims] 1. A measuring method for measuring an antenna pattern of a communication antenna mounted on a satellite using a plurality of terrestrial communication devices arranged in a communication area of a communication satellite, comprising: , And FN transmitted by the communication antenna mounted on the satellite, and the received N signals are received by the frequency selection circuit by the frequency selection circuit.
2,..., FN signals, and the level of each signal is detected by a level detector to measure the radiation pattern of a communication antenna mounted on the satellite. Measuring method. 2. A method for measuring an antenna pattern of a communication antenna mounted on a satellite using a plurality of terrestrial communication devices arranged in a communication area of a communication satellite, comprising: .., FN are transmitted to the receiving antennas of the N terrestrial communication devices, and the terrestrial communication devices transmit the signals to the terrestrial communication devices by the frequency selection device adapted to the respective frequencies. Receive only the assigned signal,
A method for measuring a satellite-mounted antenna pattern, comprising: measuring a radiation pattern of a communication antenna mounted on the satellite by detecting the received signal level with a level detector. 3. A level correction circuit for adding a variation of a level variation caused by a difference in each frequency when a level of each signal is detected by a level detector, and a bias of the variation is applied to the detected level. 3. The method for measuring a satellite-mounted antenna pattern according to claim 1, wherein the pattern is added. 4. A measurement method for measuring an antenna pattern of a communication antenna mounted on a satellite using a plurality of terrestrial communication devices arranged in a communication area of a communication satellite, comprising: The signals of the same frequency transmitted at different times T1, T2,..., TN are received by a communication antenna mounted on the satellite, and the received N signals are time-switched in accordance with the respective times. .. TN are divided into signals of T1, T2,..., TN, and the level of each signal is detected by a level detector to measure a radiation pattern of a communication antenna mounted on the satellite. How to measure antenna pattern. 5. A measuring method for measuring an antenna pattern of a communication antenna mounted on a satellite using a plurality of terrestrial communication devices arranged in a communication area of a communication satellite, comprising: At the different times T1, T2,..., TN, signals of the same frequency are transmitted to the receiving antennas of the N terrestrial communication devices, and in each terrestrial communication device, each terrestrial communication is performed by a time switch corresponding to each time. A satellite-mounted antenna for measuring a radiation pattern of a communication antenna mounted on the satellite by receiving only a signal assigned to the device and detecting the received signal level with a level detector; How to measure the pattern. 6. The plurality of terrestrial communication devices are mobile phones, the frequencies F1, F2,..., FN are terrestrial service areas when operating a satellite mobile communication service, and each of the mobile phones after operating a satellite mobile communication service. The satellite-mounted antenna pattern according to any one of claims 1 to 3, wherein a radiation pattern of a communication antenna mounted on the satellite is measured by measuring a reception electric field strength at the time of use. Measuring method.