Receiving link calibration device based on offset antenna

Abstract

The utility model discloses a receiving link calibration device based on an offset antenna, and belongs to the technical field of low-orbit satellite signal receiving. One end of a test optical transmitter and receiver for realizing optical transmission of an intermediate frequency test signal is connected with the output end of the test modulator and is used for receiving an intermediate frequency test modulation signal, and the other end of the test optical transmitter and receiver is connected with the input end of the power divider; the output end of the power divider is connected with the up-converter group and is used for realizing frequency conversion of an intermediate frequency test signal and output of radio frequency signals of different frequency bands; the antenna multi-band feed source is in wireless connection with the offset antenna, and the antenna multi-band feed source is connected with the signal link detection equipment through the ground receiving system. According to the utility model, possible problems and faults of the system can be found in time, and the calibration efficiency of the receiving link calibration equipment is greatly improved.

Description

Technical Field

[0001] The utility model belongs to the field of low-orbit satellite signal reception and discloses a satellite signal reception link calibration device based on an offset feed antenna. Background Art

[0002] With the development of earth observation technology, the reception of low-orbit remote sensing satellite signals is becoming more and more widely used in the military and civilian fields. At present, there are more and more ground remote sensing signal receiving stations built in China, and the receiving link calibration is generally to add a test coupler to the receiving front-end equipment and feed the test signal to perform self-inspection and calibration of the antenna receiving link; or to perform self-inspection and calibration of the signal receiving link by using the calibration tower or synchronous orbit satellite.

[0003] However, the method of adding a test coupler to the receiving front-end device makes it impossible to test and calibrate the antenna feed equipment; for antennas with relatively high operating frequency bands, the far-field conditions of the antenna are difficult to achieve, and it is impossible to build a calibration tower that meets the far-field and appropriate elevation conditions; for synchronous satellite calibration, since the satellite frequency and polarization are fixed, it is impossible to fully realize self-inspection and calibration of the receiving front-end equipment within the entire frequency band.

[0004] In view of the above specific situation, it is necessary to seek a more reasonable and convenient solution for self-checking and calibrating the antenna's full-band receiving performance to solve the problems arising in the background technology. Utility Model Content

[0005] The technical problem to be solved by the present invention is to avoid the deficiencies in the above-mentioned background technology, and specifically propose a receiving link calibration device based on an offset-fed antenna, which can be free from the influence of the weather and environment of the measuring station, and can perform self-inspection and calibration of the signal receiving channels of different frequency bands at the antenna receiving front end at any time, so that users can timely understand and grasp the performance of the system signal receiving channel, and timely discover possible problems and faults in the system, which also greatly improves the calibration efficiency of the receiving link calibration equipment.

[0006] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0007] A receiving link calibration device based on an offset-fed antenna comprises an antenna multi-band feed source, an offset-fed antenna, an up-converter group, a power divider, a test optical terminal, a test modulator, a signal link monitoring device and a ground receiving system;

[0008] The offset-fed antenna is mainly composed of two gain horn antennas, namely, a high-end gain horn antenna and a low-end gain horn antenna, which are respectively connected to the splitter in the antenna center body through corresponding linear polarization input ports, and are used for receiving the input of the RF test signal and transmitting the high-end frequency RF signal, and for receiving the input of the RF test signal and transmitting the corresponding frequency RF signal;

[0009] One end of the test optical terminal used to realize optical transmission of the intermediate frequency test signal is connected to the output end of the test modulator to receive the intermediate frequency test modulated signal, and the other end is connected to the input end of the power divider; the output end of the power divider is connected to the up-converter group to realize the frequency conversion of the intermediate frequency test signal and the output of radio frequency signals of different frequency bands;

[0010] The high-end gain horn antenna and the low-end gain horn antenna are respectively fixed on the antenna reflecting surface through corresponding mounting bases. The antenna multi-band feed source is wirelessly connected to the two offset-fed antennas. The antenna multi-band feed source is connected to the signal link detection equipment through a ground receiving system.

[0011] Furthermore, the test optical terminal includes a test transmitting optical terminal and a test receiving optical terminal; the test transmitting optical terminal and the test receiving optical terminal are bidirectionally interconnected, wherein the test receiving optical terminal is connected to a power splitter, and the test transmitting optical terminal is connected to a test modulator.

[0012] Compared with the background technology, the utility model has the following advantages:

[0013] (1) The utility model is easy to operate and does not require personnel to perform complicated operations. After power is turned on, the test modulator is configured through the station control software, and then the signal link monitoring equipment realizes the automatic test and calibration of the receiving performance.

[0014] (2) The utility model is fully functional and can realize automated testing and calibration of system receiving link performance indicators and implement RF wireless closed-loop testing.

[0015] (3) The utility model greatly improves the efficiency of antenna receiving link self-checking and calibration.

[0016] (4) The highest operating frequency band suitable for the present invention is the Ka band, and it has the characteristic of high calibration accuracy.

[0017] (5) The utility model has the advantages of relatively simple structure and stable and reliable use. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the principle of an embodiment of the utility model.

[0019] Figure 2 The figure is a schematic diagram of the working principle of the offset-fed antenna of the utility model. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1-2 The specific implementation methods of the utility model are further described in detail with examples.

[0021] Depend on Figure 1As shown, the receiving link calibration device based on the offset fed antenna of the utility model is applied to the low-orbit remote sensing satellite signal receiving system. The receiving link calibration device based on the offset fed antenna is mainly composed of an antenna multi-band feed source, an offset fed antenna, an up-converter group, a power divider, a test optical terminal, a test modulator, a signal link monitoring equipment and a ground receiving system.

[0022] Figure 1 The up-converter group described in the invention mainly includes up-converters of five frequency bands, and the input intermediate frequency is 1200MHz or 720MHz, which can realize the up-conversion of intermediate frequency test signals and the output of radio frequency signals of different frequency bands.

[0023] Figure 1 The power divider described in the figure has one input and six simultaneous outputs, and is used to realize the branching of intermediate frequency test signals in different frequency bands.

[0024] Figure 1 The test optical terminal described in the foregoing includes a test transmitting optical terminal and a test receiving optical terminal, and is used to realize optical transmission of intermediate frequency test signals.

[0025] Figure 1 The test modulator described in the specification is mainly used to provide a 1200MHz or 720MHz intermediate frequency test modulation signal, wherein the test modulator is provided by the high-speed demodulation terminal.

[0026] Figure 1 The signal link monitoring equipment described in the invention is used to measure the spectrum characteristics of the radio frequency signal, realize self-inspection and calibration of the system receiving link performance, judge the working status of the receiving channel, and complete the overall performance detection of the whole link from antenna feed to receiving demodulation.

[0027] Figure 1 The signal link monitoring device described in the invention is a 2U chassis, which is installed at an appropriate position of the RF signal output to facilitate the detection of the RF signal receiving performance. After the detection is completed, the RF spectrum can be transmitted to the equipment room through the network to realize the monitoring of the RF signal spectrum.

[0028] Depend on Figure 2 As shown, the offset-fed antenna is composed of two standard gain horn antennas, one of which is an offset-fed antenna (high end), equipped with a linear polarization input port, connected to the splitter in the center of the antenna, receiving the input of the RF test signal, and used to transmit the high-end frequency RF signal. The other is an offset-fed antenna (low end), equipped with a linear polarization input port, connected to the splitter in the center of the antenna, receiving the input of the RF test signal, and used to transmit the low-end frequency RF signal.

[0029] Working principle of the receiving link calibration device based on offset fed antenna:

[0030] The receiving link calibration based on offset-fed antenna mainly feeds the test signal from the receiving antenna entrance through the offset-fed antenna to complete the overall system performance detection of the whole link from antenna feed source to receiving demodulation, which is used to judge the overall link performance such as system sensitivity; at the same time, the LNA output signal is split to the signal link monitoring equipment, and the performance of the test signal output by the LNA is further measured to judge the LNA performance. It can also be used for daily actual signal monitoring. In this mode, the intermediate frequency test signal generated by the test modulator is output to the up-converter through the intermediate frequency exchange matrix, converted to RF signals of different frequency bands, input to the multi-band feed source through the offset-fed antenna, and then received through the receiving channel to judge the channel status. At the same time, it is branched to the signal link monitoring equipment through the LNA to measure the spectrum characteristics of the RF test signal.

[0031] The above description is only the best specific implementation mode of the utility model, but the protection scope of the utility model is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the utility model should be included in the protection scope of the utility model.

[0032] The contents not described in detail in the utility model specification belong to the common knowledge of professionals in this field.

Claims

1. A receiving link calibration device based on an offset-fed antenna, characterized in that: It includes antenna multi-band feed, offset-fed antenna, up-converter group, power divider, test optical transceiver, test modulator, signal link monitoring equipment and ground receiving system; The offset-fed antenna is mainly composed of two gain horn antennas, namely, a high-end gain horn antenna and a low-end gain horn antenna, which are respectively connected to the splitter in the antenna center body through corresponding linear polarization input ports, and are used for receiving the input of the RF test signal and transmitting the high-end frequency RF signal, and for receiving the input of the RF test signal and transmitting the corresponding frequency RF signal; One end of the test optical terminal used to realize optical transmission of the intermediate frequency test signal is connected to the output end of the test modulator to receive the intermediate frequency test modulated signal, and the other end is connected to the input end of the power divider; the output end of the power divider is connected to the up-converter group to realize the frequency conversion of the intermediate frequency test signal and the output of radio frequency signals of different frequency bands; The high-end gain horn antenna and the low-end gain horn antenna are respectively fixed on the antenna reflecting surface through corresponding mounting bases. The antenna multi-band feed source is wirelessly connected to the two offset-fed antennas. The antenna multi-band feed source is connected to the signal link detection equipment through a ground receiving system.

2. A receiving link calibration device based on an offset-fed antenna according to claim 1, characterized in that: The test optical terminal comprises a test transmitting optical terminal and a test receiving optical terminal; the test transmitting optical terminal and the test receiving optical terminal are bidirectionally interconnected, wherein the test receiving optical terminal is connected to a power splitter, and the test transmitting optical terminal is connected to a test modulator.

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