CN107276643A - A kind of moving communication satellite multi-beam carrier/interface ratio ground testing system and method - Google Patents

Abstract

A mobile communication satellite multi-beam carrier-to-interference ratio ground test system and method, the system includes a power supply, a control module, a multi-channel signal source, a transmitting antenna simulator, and a spectrum analyzer; the power supply is a control module, a multi-channel signal source, and a transmitting antenna simulator Power supply with the spectrum analyzer, the multi-channel signal source provides test signals for the DUT, the transmitting antenna simulator realizes the simulation of the response of the reflector and the feed source in the large multi-beam antenna to the signal, and the control module controls the phase shift in the transmitting antenna simulator , the phase shift and attenuation parameters of the attenuation component, and the spectrum analyzer is used to read the output test signal level. The invention mainly aims at the mobile communication satellite load using a large multi-beam antenna, and can simulate the response of the feed source and reflector of the large multi-beam antenna through a transmitting antenna simulator, so as to realize the ground test of the carrier-to-interference ratio of the multi-beam load of the mobile communication satellite.

Description

A mobile communication satellite multi-beam carrier-to-interference ratio ground test system and method

technical field

The invention relates to a mobile communication satellite multi-beam load beam carrier-to-interference ratio ground test system and method, which are suitable for the mobile communication satellite multi-beam load beam carrier-to-interference ratio ground test and belong to the mobile communication satellite payload technical field.

Background technique

The multi-beam load based on reflector multi-beam antenna is the core technology of geostationary mobile communication satellites. The multi-beam load includes transponders, beamforming equipment, feed arrays, and large-aperture antennas. The size of large-aperture antennas can reach ten meters or several Ten meters, as shown in Figure 2.

In order to improve the utilization efficiency of frequency resources, frequency multiplexing technology is generally used, and 7-color multiplexing and 4-color multiplexing are commonly used.

Due to the existence of sidelobes in beams, there is mutual interference between beams of the same frequency, that is, the carrier-to-interference ratio (C/I) between beams of the same frequency is a key parameter that affects system capacity and communication quality.

The literature [Sudhakar K.Rao, Desibn and Analysis of Multiple Beam Reflector Antennas, IEEE Antennas and Propagation Magazine, Vpl.41, No.4, August 1999] studies the C/I of multi-beam antennas, and gives the same-frequency The definition of C/I between beams and a calculation method, the provided model and formula can calculate the C/I of each beam at a certain point (Figure 4), and the middle beam 0 is at point The formula for calculating C/I above is:

where P _k , Respectively denote the output power of beam i carrier and at point on the gains.

Due to the use of large-scale deployable antennas, it is difficult to measure the C/I of the load under the existing site conditions during the development stage. At present, semi-physical methods are used to test the radiation data of the feed array, which is substituted into the commercial software Grasp to calculate the distance of all beams. field, C/I is calculated using the sum method model provided in the above literature. This method is also the current general method.

Since the beam test cannot take into account the intermodulation in the active device when multiple carriers in multiple beams using the same frequency work simultaneously, the C/I given by this method generally cannot fully describe the performance of the system.

Contents of the invention

The technical solution problem of the present invention is: overcome the deficiencies in the prior art, provide a kind of mobile communication satellite multi-beam load beam carrier-to-interference ratio ground test system and method, realize the mobile communication satellite multi-beam load C/ that adopts large-scale multi-beam antenna The ground test of I improves the comprehensiveness and accuracy of the test.

Technical solution of the present invention is:

A mobile communication satellite multi-beam carrier-to-interference ratio ground test system, including: a power supply, a control module, a multi-channel signal source, a transmitting antenna simulator and a spectrum analyzer;

The power supply supplies power to the control module, multi-channel signal source, transmitting antenna simulator and spectrum analyzer, the multi-channel signal source provides test signals for the DUT, and the DUT outputs excitation signals of M-channel feeds to the transmitting antenna simulator for Form multiple beams; the transmitting antenna simulator realizes the simulation of the response of the reflector and the feed source to the signal in the large multi-beam antenna according to the received M-channel feed source excitation signal, and the control module according to different directions The response of the lower feed source and the reflector to the feed excitation signal controls the operation of the transmitting antenna simulator. The spectrum analyzer is used to read the test signal level output by the transmitting antenna simulator. M is the number of feed sources for the multi-beam load of the mobile communication satellite.

The multi-channel signal source outputs K channels of equal-amplitude signals with a frequency interval of 100KHz, and K is the number of beams of the same frequency in the multi-beam load of the mobile communication satellite.

The DUT is a transponder channel and a beam forming device in a multi-beam load of a mobile communication satellite.

The transmitting antenna simulator includes M path variable phase shifting components, attenuation components and power combiner;

The variable phase-shift component performs phase-shift processing on the M-channel feed excitation signals output by the DUT according to the phase-shift parameters provided by the control module, and the attenuation component performs attenuation processing on the signals after phase-shift processing according to the attenuation parameters provided by the control module , the power synthesizer performs power synthesis on the M signals after attenuation processing, and generates the output signal of the transmitting antenna simulator, that is, the test signal.

The test signal refers to the K-way beam output by the transmitting antenna simulator in the azimuth signal of.

The m-th variable phase-shifting and attenuating components in the transmitting antenna simulator are in the azimuth The amount of phase shift and attenuation is equal to that when the m-th feed is excited by unit 1, the far field of the antenna is in the azimuth electric field value The magnitude and phase of , that is:

Among them, A _m,i and Φ _m,i are the magnitude and phase of the electric field, respectively.

The amplitude and phase A _m,i and Φ _m,i of the electric field have an accuracy of ±0.5dB and ±10 degrees, and the attenuation range of the attenuation component is 0-35dB.

A test method based on the mobile communication satellite multi-beam carrier-to-interference ratio ground test system, the steps are as follows:

Step 1: The multi-carrier signal source outputs K channels of equal-amplitude signals S1, S2...SK with a frequency interval of 100KHz, which are used to equivalently work at the same time. The carrier signal of the same frequency is connected to the corresponding beam input port of the DUT, and the DUT The duplexer and the feed source of the component are disconnected, and the duplexer is connected to the input port of the transmitting antenna simulator;

Step 2: The control module controls the phase-shift parameters and attenuation parameters A _m,i and Φ _m,i of the transmitting antenna simulator, located at the position

Step 3: Connect the spectrum analyzer to the output port of the transmitting antenna simulator, read and record the output power data S1,i,S2,i...SK,i corresponding to S1, S2...SK on the spectrum analyzer;

Step 4: Use the following formula to calculate the kth beam at load-to-dry ratio

Step 5: Repeat steps 2 to 4 to complete the C/I test of all K beams to be tested at all points.

The beneficial effect of the present invention compared with prior art is:

(1) The present invention can realize the ground test of the multi-beam load C/I of the mobile communication satellite adopting a large-scale multi-beam antenna, and can accurately test and verify the C/I of the multi-beam load before satellite launch, which improves the timeliness and comprehensiveness of the test sex and accuracy.

(2) The test system and method provided by the present invention work through the control module control system, and C/I can be obtained without the need for each beam pattern in the test antenna, which greatly improves the test efficiency compared with the prior art.

(3) The present invention realizes the simulation of the response of the reflector and the feed source to the signal in the large multi-beam antenna through a group of phase shifting and attenuating components and a power combiner, and provides the design requirements of the phase shifting and attenuating components.

Description of drawings

Fig. 1 is a schematic diagram of the system architecture of the present invention;

Fig. 2 is a functional block diagram of the mobile communication satellite multi-beam load that can use the present invention;

Figure 3 is an equivalent block diagram of the multi-beam load shown in Figure 2;

Figure 4 is a schematic diagram of the calculation method of the same frequency beam C/I given in the literature;

Fig. 5 is a schematic diagram of a transmitter antenna simulator in the present invention;

Figure 6 is the C/I design result of the implementation case;

Fig. 7 is the result tested with the present invention.

detailed description

Specific embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

The present invention provides a mobile communication satellite multi-beam load beam carrier-to-interference ratio ground test system and method, which are used to test the carrier-to-interference ratio of the mobile communication satellite multi-beam load (as shown in Figure 2) beam on the ground;

As shown in Figure 1, ground test system of the present invention comprises power supply, control module, multi-channel signal source, transmitting antenna emulator and spectrum analyzer;

The power supply supplies power to the control module, multi-channel signal source, transmitting antenna simulator and spectrum analyzer, the multi-channel signal source provides test signals for the DUT, and the DUT outputs excitation signals of M-channel feeds to the transmitting antenna simulator for Form multiple beams; the transmitting antenna simulator realizes the simulation of the response of the reflector and the feed source to the signal in the large multi-beam antenna according to the received M-channel feed source excitation signal, and the control module according to different directions The response of the lower feed source and the reflector to the feed source excitation signal controls the operation of the transmitting antenna simulator, and the spectrum analyzer is used to read the test signal level output by the transmitting antenna simulator, and M is the number of feed sources of the mobile communication satellite multi-beam load;

Among the present invention, the multi-channel signal source is a general-purpose multi-channel signal source, which can output K-channel frequency interval 100KHz equal-amplitude signals, and K is the same-frequency beam number in the multi-beam load of mobile communication satellites; the K-channel test signal output by the multi-channel signal source Enter the DUT (the transponder channel and beamforming equipment in the multi-beam load of the mobile communication satellite (as shown in Figure 2 and 3), the DUT can be equivalent to a network with K input and M output, and the output of the DUT is the excitation signal of M feeds, used to excite the feed array to form multi-beams;

Transmitting antenna emulator (as shown in Figure 5) among the present invention, comprises M road variable phase-shifting, attenuation assembly and an M-in-one power combiner; Variable attenuation assembly processes phase-shifting according to the attenuation parameter that control module provides After the signal is attenuated, the variable phase-shift component performs phase-shift processing on the M-channel feed source excitation signals output by the DUT according to the phase-shift parameters provided by the control module, and the power combiner performs phase-shift processing on the M-channel signals after phase-shift processing. Power combining to generate the output signal of the transmit antenna simulator, ie the test signal.

Simulate the response of the corresponding feed source and reflector to the feed source excitation signal through M-channel variable phase shifting and attenuation components; the control module according to different orientations The response of the lower feed source and the reflector to the feed excitation signal controls the variable phase shift and attenuation components in the transmitting antenna simulator; the output of the transmitting antenna simulator is the K-way beam in the azimuth signal of;

The m-th variable phase-shifting and attenuating components in the transmitting antenna simulator are in the azimuth The amount of phase shift and attenuation is equal to that when the kth feed is excited by unit 1 power, the far field of the antenna is in the azimuth The magnitude and phase of the electric field value of :

Among them, A _m,i and Φ _m,i are the amplitude and phase of the electric field respectively;

In the present invention, the control module stores the phase shifting and attenuation parameters of all M variable phase shifting and attenuation components at all required test points as a phase shifting and attenuation parameter table, and reads and controls the transmitting antenna according to the azimuth angle of the test point during the test. Variable phase shifting, attenuation components work in the simulator.

In the present invention, the spectrum analyzer is a general-purpose instrument, which is used to monitor and read the K-way beam in the azimuth signal level.

Based on the above-mentioned ground test system, a test method is also proposed in the present invention, which is realized by the following steps:

Step 1: The multi-carrier signal source outputs K (number of beams of the same frequency) channels of equal-level signals S1, S2...Sk with a frequency interval of 100KHz, which are used to equivalently work at the same time. Carrier signals of the same frequency are connected to the beams corresponding to the load The input port, the duplexer of the load is disconnected from the feed source, and the duplexer is connected to the input port of the transmitting antenna simulator (use the transmitting antenna simulator to replace the feed array and reflector of the large multi-beam antenna);

Step 2: The control module controls the phase-shift attenuation parameters A _m,i and Φ _m,i of the transmitting antenna simulator, located at the position

Step 3: Connect the spectrum analyzer to the output port of the transmitting antenna simulator, read and record the output power data S1, i, S2, i...Sk,i corresponding to S1, S2...Sk on the spectrum analyzer;

Step 4: Use the following formula to calculate the kth beam at of

Step 5: Repeat steps 2 to 4 to complete the C/I test of all M beams to be tested at all points.

Example:

The multi-beam load of a mobile communication satellite is shown in Figure 2. The system has 109 beams, and 64 feeds can be shared by transmitting and receiving through duplexers. to 16 times.

Using the system proposed by the present invention, according to the method of the present invention, the C/I of all beams is tested, and the minimum C/I in the service area of all beams is counted.

After calculation, when the phase-shifting and attenuation components of the transmitting antenna simulator meet the requirements of the amplitude and phase accuracy: ±0.5dB, ±10 degrees, and the attenuation range of the attenuator is 0-35dB, the main lobe error of the beam is less than 0.01dB, and the side lobe error is less than 0.01dB. 1dB@30dBc (that is, the error of the sidelobe 30dB lower than the main lobe level is about 1dB, and the error of the sidelobe level of each beam is about 1‰). It can be seen that the influence on C is 0.01dB, and the maximum influence on I is about 6‰. The overall test error is about 0.03dB.

The statistics of the design results and the actual measurement results are shown in Figure 6 and Figure 7, and the actual measurement results are consistent with the design results.

Parts not described in detail in the present invention belong to the common knowledge of those skilled in the art.

Claims (8)

1. A mobile communication satellite multi-beam carrier-to-interference ratio ground test system is characterized in that comprising: power supply, control module, multi-channel signal source, transmitting antenna simulator and spectrum analyzer; The power supply supplies power to the control module, multi-channel signal source, transmitting antenna simulator and spectrum analyzer, the multi-channel signal source provides test signals for the DUT, and the DUT outputs excitation signals of M-channel feeds to the transmitting antenna simulator for Form multiple beams; the transmitting antenna simulator realizes the simulation of the response of the reflector and the feed source to the signal in the large multi-beam antenna according to the received M-channel feed source excitation signal, and the control module according to different directions The response of the lower feed source and the reflector to the feed excitation signal controls the operation of the transmitting antenna simulator. The spectrum analyzer is used to read the test signal level output by the transmitting antenna simulator. M is the number of feed sources for the multi-beam load of the mobile communication satellite. 2. a kind of mobile communication satellite multi-beam carrier-to-interference ratio ground test system according to claim 1, is characterized in that: described multi-channel signal source outputs the equal-amplitude signal of K road frequency interval 100KHz, and K is mobile communication satellite multiple The number of beams with the same frequency in the beam load. 3. A mobile communication satellite multi-beam carrier-to-interference ratio ground test system according to claim 1, characterized in that: said DUT is a transponder channel and a beamforming device in a mobile communication satellite multi-beam load. 4. a kind of mobile communication satellite multi-beam carrier-to-interference ratio ground test system according to claim 1, is characterized in that: described transmitting antenna emulator comprises M path variable phase-shift assembly, attenuation assembly and power combiner; The variable phase-shift component performs phase-shift processing on the M-channel feed excitation signals output by the DUT according to the phase-shift parameters provided by the control module, and the attenuation component performs attenuation processing on the signals after phase-shift processing according to the attenuation parameters provided by the control module , the power synthesizer performs power synthesis on the M signals after attenuation processing, and generates the output signal of the transmitting antenna simulator, that is, the test signal. 5. a kind of mobile communication satellite multi-beam carrier-to-interference ratio ground test system according to claim 4, is characterized in that: described test signal refers to that the K road beam that transmitting antenna emulator outputs is in azimuth signal of. 6. A kind of mobile communication satellite multi-beam carrier-to-interference ratio ground test system according to claim 4, is characterized in that: the mth road variable phase shifting in the transmitting antenna emulator, the attenuation component is in the azimuth The amount of phase shift and attenuation is equal to that when the m-th feed is excited by unit 1, the far field of the antenna is in the azimuth electric field value The magnitude and phase of , that is: Among them, A _m,i and Φ _m,i are the magnitude and phase of the electric field, respectively. 7. A kind of mobile communication satellite multi-beam carrier-to-interference ratio ground test system according to claim 6, is characterized in that: the amplitude of electric field, phase Am, _i , the accuracy of Φ _{m, i} meet ±0.5dB, ±10 The attenuation range of the attenuation component is 0~35dB. 8. a method of testing based on the realization of the mobile communication satellite multi-beam carrier-to-interference ratio ground test system of claim 1, is characterized in that the steps are as follows: Step 1: The multi-carrier signal source outputs K channels of equal-amplitude signals S1, S2...SK with a frequency interval of 100KHz, which are used to equivalently work at the same time. The carrier signal of the same frequency is connected to the corresponding beam input port of the DUT, and the DUT The duplexer and the feed source of the component are disconnected, and the duplexer is connected to the input port of the transmitting antenna simulator; Step 2: The control module controls the phase-shift parameters and attenuation parameters A _m,i and Φ _m,i of the transmitting antenna simulator, located at the position Step 3: Connect the spectrum analyzer to the output port of the transmitting antenna simulator, read and record the output power data S1,i,S2,i...SK,i corresponding to S1, S2...SK on the spectrum analyzer; Step 4: Use the following formula to calculate the kth beam at load-to-dry ratio Step 5: Repeat steps 2 to 4 to complete the C/I test of all K beams to be tested at all points.