Gain test method, device and system for unit-level digital dome conformal antenna array

Abstract

The invention discloses a unit-level digital dome conformal antenna array gain test method, device and system, and belongs to the technical field of array antennae, and the method comprises the steps: S1, setting a signal source as a tested frequency point, opening the signal source, and calibrating the input signal power at a tested dome conformal antenna array; s2, calculating a signal-to-noise ratio of an antenna aperture; s3, controlling beam forming equipment by using a computer to enable the beam of the dome conformal antenna array to point to a transmitting antenna; s4, collecting data in the closed state and the open state of the signal source, and calculating the output signal-to-noise ratio received and processed by the array antenna; and S5, calculating to obtain the array gain. According to the method, the whole array and the beam forming equipment can be tested together in the free space, the antenna array gain can be calculated by combining the improvement degree of the signal-to-noise ratio with the noise coefficient only through common general test equipment, and the method has the characteristics of low requirement on test conditions, small test workload and complete test.

Description

Technical Field

[0001] The present invention relates to the technical field of array antennas, and more specifically, to a unit-level digital spherical conformal antenna array gain testing method, device and system. Background Art

[0002] For the unit-level digital spherical conformal antenna array, its gain cannot be directly tested. It is generally tested by indirect method. The basic idea is as follows:

[0003] a) During the test, first test the near-field pattern of each unit antenna under near-field conditions;

[0004] b) Obtaining the far-field pattern of the unit antenna through near-field to far-field mathematical transformation;

[0005] c) Based on the far-field pattern and the array beamforming algorithm, the three-dimensional pattern of the array is simulated by numerical calculation on the computer side to obtain the gain.

[0006] The test schematic diagram of the test scheme under the above basic idea is as follows Figure 1 As shown in the figure, the spherical top conformal antenna array to be tested is placed at the center of the sphere in the spherical near-field microwave darkroom. The specific steps for testing a unit antenna are as follows:

[0007] a) Adjust the turntable so that the 0° line of the antenna array under test coincides with the spherical near-field reference line;

[0008] b) Generate a test frequency signal and inject it into the antenna of the unit under test;

[0009] c) Collecting test data by using multiple probes arranged on the arc-shaped bracket to complete the collection of test data of all pitches in the current azimuth;

[0010] d) Adjust the turntable to the next position and repeat step c) until the test data collection of the current unit antenna from 0° to 360° is completed;

[0011] e) Repeat steps b) to d) to complete the test data collection of all unit antennas in the full array.

[0012] Through mathematical transformation, the near-field and far-field transformation of all unit antennas is completed, and then the three-dimensional calculation of the beam is completed through numerical calculation to obtain the gain. The array scale is usually several hundred yuan, and the testing workload is quite large.

[0013] The main disadvantages of existing methods are as follows:

[0014] a) It is necessary to use a spherical near-field microwave darkroom, which has complex conditions and high cost;

[0015] b) Each unit antenna needs to be tested and the beam synthesized by mathematical methods. When the array size reaches several hundred elements, the workload is enormous.

[0016] c) Only the antenna array participated in the test, the beamforming was simulated by computer, and the back-end beamforming equipment was not involved in the test, resulting in a test blind spot. Summary of the invention

[0017] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a unit-level digital spherical conformal antenna array gain test method, device and system, which can test the entire array together with the beamforming equipment in free space, only require ordinary general test equipment, and calculate the antenna array gain by combining the signal-to-noise ratio improvement degree with the noise coefficient. It has the characteristics of low test condition requirements, small test workload and complete test.

[0018] The object of the present invention is achieved through the following solutions:

[0019] A unit-level digital spherical conformal antenna array gain test method comprises the following steps:

[0020] S1, set the signal source to the measured frequency point, turn on the signal source, and calibrate the input signal power S at the measured spherical conformal antenna array. i ;

[0021] S2, calculate the signal-to-noise ratio (SNR) of the antenna aperture i_dB ;

[0022] S3, using a computer to control the beam forming device so that the beam of the spherical conformal antenna array points to the transmitting antenna;

[0023] S4, collect data when the signal source is turned off and on, and calculate the output signal-to-noise ratio (SNR) after receiving and processing by the array antenna. o_dB ;

[0024] S5, using SNR i_dB and SNR o_dB , calculate the array gain G dB .

[0025] Furthermore, in step S1, the calibrated input signal power S i , specifically including the following sub-steps:

[0026] Before the test, the signal source generates the signal at the frequency point to be tested, which is radiated and output by the antenna. The spectrum analyzer reading S is received by the receiver antenna at the spherical conformal antenna array to be tested. r , the signal power S reaching the antenna interface i , calculated as follows:

[0027] S i =S r +LG r ;

[0028] Where L is the cable insertion loss between the receiving test antenna and the spectrum analyzer; G r Test antenna gain for reception.

[0029] Furthermore, in step S2, the signal-to-noise ratio SNR of the antenna aperture is calculated. i_dB , specifically including the following sub-steps:

[0030] Calculate according to the following formula:

[0031] SNR i_dB =S i -N i ;

[0032] Where, the input noise power N i =-114+10logB, where B is the receiving bandwidth of the receiving channel of the antenna array to be tested.

[0033] Further, in step S4, the signal-to-noise ratio SNR after receiving and processing by the array antenna is calculated. o_dB , specifically including the following sub-steps:

[0034] When the test signal is not radiated, collect N noise time domain points n 1 ....n i , after radiating the test signal, collect N signal plus noise time domain points a 1 ....a i , calculate the output signal-to-noise ratio SNR according to the following formula o_dB :

[0035]

[0036] Further, in step S5, the use of SNR i_dB and SNR o_dB , calculate the array gain G dB , specifically including the following sub-steps:

[0037] SNR i_dB and SNR o_dB Substitute the following formula to calculate the array gain G dB :

[0038] G dB =NF dB +SNR o_dB -SNR i_dB ;

[0039] Among them, NF dB is the noise coefficient, which is an inherent characteristic of the channel.

[0040] Furthermore, the antenna includes an L-band antenna.

[0041] Further, the array comprises a 512-element array.

[0042] Furthermore, the number of the measured frequency points includes 3, and the elevation angles relative to the center of the antenna array are 0°, 10° and 30° respectively.

[0043] A unit-level digital spherical conformal antenna array gain test device comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is loaded by the processor, any of the above methods is executed.

[0044] A unit-level digital spherical conformal antenna array gain test system comprises the device as described above.

[0045] The beneficial effects of the present invention include:

[0046] a) The requirements for test conditions are reduced: the existing spherical near-field darkroom test method needs to be tested in a spherical near-field darkroom, while the method of the present invention is tested in free space.

[0047] c) Shortening of test cycle: When the method of the present invention is used to test a 512-element array, the test cycle is shortened to 25% of that of the existing method.

[0048] c) Comparable test accuracy: Through comparative tests, the unit-level digital dome conformal array gain data obtained by the method of the present invention differs from that of the existing method by no more than 0.5 dB. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0050] Figure 1 It is a schematic diagram of spherical near field test of the existing test method;

[0051] Figure 2 This is a schematic diagram of a test scenario for the method of the present invention;

[0052] Figure 3 This is a schematic diagram of a test scenario for Embodiment 1 of the method of the present invention. DETAILED DESCRIPTION

[0053] All features disclosed in all embodiments in this specification, or steps in all methods or processes implicitly disclosed, except for mutually exclusive features and / or steps, can be combined and / or expanded or replaced in any manner.

[0054] The specific implementation process of the present invention is as follows:

[0055] In a preferred embodiment, it is particularly related to the digital conformal antenna array gain test. Specifically, the invention is conceived as follows: the physical meaning of the receiving antenna gain is reflected in the improvement of the signal-to-noise ratio. When testing by the field radiation method, the antenna gain test is converted into the test of the output signal signal-to-noise ratio. The signal-to-noise ratio improvement relationship expressed by a linear value is as follows: SNR i G = NF SNR o Among them, SNR i is the signal-to-noise ratio of the antenna aperture, G is the array gain, NF is the noise factor, SNR o is the signal-to-noise ratio after receiving and processing by the array antenna. After conversion to logarithmic representation, it is expressed as follows:

[0056] G dB =NF dB +SNR o_dB -SNR i_dB (1);

[0057] The receiving antenna gain is calculated using the above formula. Input signal power S i It can be calibrated before testing (unit: dBm), such as Figure 2 As shown in the figure, before the test, the signal source generates the signal at the frequency point to be tested, which is radiated and output by the antenna, and the spectrum analyzer reading S is received by the receiver antenna at the antenna array to be tested. r (Unit: dBm), the signal power S reaching the antenna aperture i , calculated as follows:

[0058] S i =S r +LG r (2);

[0059] Where L is the cable insertion loss between the receiving test antenna and the spectrum analyzer, in dB; G r Antenna gain for receiving test, in dB.

[0060] Input noise power (unit: dBm) N i =-114+10logB, B is the receiving bandwidth of the receiving channel of the antenna array to be tested, unit: MHz.

[0061] SNR i_dB =S i -N i (3);

[0062] The output signal-to-noise ratio test process is as follows: When the test signal is not radiated, collect N noise time domain points n 1 ....n i, after radiating the test signal, collect N signal plus noise time domain points a 1 ....a i , output signal-to-noise ratio:

[0063]

[0064] Substituting the calculation results into formula (1), G dB That is the dome array antenna gain. The test steps when using the method of the present invention are as follows:

[0065] a) Set the signal source to the frequency to be measured, turn on the signal source, and use a spectrum analyzer to calibrate the input signal power S at the spherical conformal antenna array to be measured according to formula (2): i ;

[0066] b) Calculate SNR according to formula (3) i_dB ;

[0067] c) controlling the beam forming device with a control computer so that the beam of the spherical conformal antenna array points toward the transmitting antenna;

[0068] d) Collect data with the signal source turned off and on, and calculate the SNR according to formula (4) o_dB ;

[0069] e) SNR i_dB and SNR o_dB Substituting into formula (1), we get the array gain G dB NF dB The NF of a channel in the array is selected as the channel intrinsic characteristic dB Substitute the design value into the formula for calculation.

[0070] In other embodiments, the method of the present invention is used for a unit-level digital dome conformal array gain test, and good results are achieved. The test scenario is as follows: Figure 3 As shown. The test was carried out in free space, with the horizontal distance between the test tower and the antenna array being about 110 meters. Three test points were set on the tower, with elevation angles of 0°, 10° and 30° relative to the center of the antenna array. A beacon signal was sent by a signal source at the three test points, and the gain test was performed using the method of the present invention. The test cycle was shortened by 75% compared with the test in a spherical near-field microwave darkroom, and the test accuracy was comparable, which fully demonstrated the effectiveness of the method of the present invention.

[0071] It should be noted that within the scope of protection defined in the claims of the present invention, the following embodiments can be combined and / or expanded or replaced in any logical way from the above specific implementation methods, such as disclosed technical principles, disclosed technical features or implicitly disclosed technical features.

[0072] Example 1

[0073] A unit-level digital spherical conformal antenna array gain test method comprises the following steps:

[0074] S1, set the signal source to the measured frequency point, turn on the signal source, and calibrate the input signal power S at the measured spherical conformal antenna array. i ;

[0075] S2, calculate the signal-to-noise ratio (SNR) of the antenna aperture i_dB ;

[0076] S3, using a computer to control the beam forming device so that the beam of the spherical conformal antenna array points to the transmitting antenna;

[0077] S4, collect data when the signal source is turned off and on, and calculate the output signal-to-noise ratio (SNR) after receiving and processing by the array antenna. o_dB ;

[0078] S5, using SNR i_dB and SNR o_dB , calculate the array gain G dB .

[0079] Example 2

[0080] Based on Example 1, in step S1, the calibrated input signal power S i , specifically including the following sub-steps:

[0081] Before the test, the signal source generates the signal at the frequency point to be tested, which is radiated and output by the antenna. The spectrum analyzer reading S is received by the receiver antenna at the spherical conformal antenna array to be tested. r , the signal power S reaching the antenna interface i , calculated as follows:

[0082] S i =S r +LG r ;

[0083] Where L is the cable insertion loss between the receiving test antenna and the spectrum analyzer; G r Test antenna gain for reception.

[0084] Example 3

[0085] Based on Example 2, in step S2, the signal-to-noise ratio SNR of the antenna aperture is calculated. i_dB , specifically including the following sub-steps:

[0086] Calculate according to the following formula:

[0087] SNR i_dB =S i -N i;

[0088] Where, the input noise power N i =-114+10logB, where B is the receiving bandwidth of the receiving channel of the antenna array to be tested.

[0089] Example 4

[0090] Based on Example 3, in step S4, the signal-to-noise ratio SNR after receiving and processing by the array antenna is calculated. o_dB , specifically including the following sub-steps:

[0091] When the test signal is not radiated, collect N noise time domain points n 1 ....n i , after radiating the test signal, collect N signal plus noise time domain points a 1 ....a i , calculate the output signal-to-noise ratio SNR according to the following formula o_dB :

[0092]

[0093] Example 5

[0094] Based on Example 4, in step S5, the use of SNR i_dB and SNR o_dB , calculate the array gain G dB , specifically including the following sub-steps:

[0095] SNR i_dB and SNR o_dB Substitute the following formula to calculate the array gain G dB :

[0096] G dB =NF dB +SNR o_dB -SNR i_dB ;

[0097] Among them, NF dB is the noise coefficient, which is an inherent characteristic of the channel.

[0098] Example 6

[0099] Based on embodiment 1, the antenna includes an L-band antenna.

[0100] Example 7

[0101] Based on Example 1, the array includes a 512-element array.

[0102] Example 8

[0103] Based on Example 1, the number of the measured frequency points includes 3, and the elevation angles relative to the center of the antenna array are 0°, 10° and 30° respectively.

[0104] Example 9

[0105] A unit-level digital spherical conformal antenna array gain test device comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is loaded by the processor, a method as described in any one of Embodiments 1 to 8 is executed.

[0106] Example 10

[0107] A unit-level digital spherical conformal antenna array gain test system includes the device as described in Example 9.

[0108] The units involved in the embodiments of the present invention may be implemented by software or hardware, and the units described may also be arranged in a processor. The names of these units do not, in some cases, limit the units themselves.

[0109] According to one aspect of an embodiment of the present invention, a computer program product or a computer program is provided, the computer program product or the computer program includes a computer instruction, and the computer instruction is stored in a computer-readable storage medium. A processor of a computer device reads the computer instruction from the computer-readable storage medium, and the processor executes the computer instruction, so that the computer device executes the method provided in the above various optional implementations.

[0110] As another aspect, an embodiment of the present invention further provides a computer-readable medium, which may be included in the electronic device described in the above embodiment; or may exist independently without being assembled into the electronic device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by an electronic device, the electronic device implements the method described in the above embodiment.

Claims

1. A unit-level digital spherical conformal antenna array gain test method, characterized in that: The following steps are involved: S1, set the signal source to the measured frequency, turn on the signal source, and calibrate the input signal power S at the measured spherical conformal antenna array. i ; S2, calculate the signal-to-noise ratio (SNR) of the antenna aperture i_dB ; S3, using a computer to control the beam forming device so that the beam of the spherical conformal antenna array points to the transmitting antenna; S4, collect data when the signal source is turned off and on, and calculate the output signal-to-noise ratio (SNR) after receiving and processing by the array antenna. o_dB ; S5, using SNR i_dB and SNR o_dB , calculate the array gain G dB .

2. The unit-level digital spherical conformal antenna array gain test method according to claim 1, characterized in that: In step S1, the calibrated input signal power S i , specifically including the following sub-steps: Before the test, the signal source generates the signal at the frequency point to be tested, which is radiated and output by the antenna. The spectrum analyzer reading S is received by the receiver antenna at the spherical conformal antenna array to be tested. r , the signal power S reaching the antenna interface i , calculated as follows: S i =S r +L-G r ; Where L is the cable insertion loss between the receiving test antenna and the spectrum analyzer; G r Test antenna gain for reception.

3. The unit-level digital spherical conformal antenna array gain test method according to claim 2, characterized in that: In step S2, the signal-to-noise ratio (SNR) of the antenna aperture is calculated. i_dB , specifically including the following sub-steps: Calculate according to the following formula: SNR i_dB =S i -N i ; Where, the input noise power N i =-114+10logB, where B is the receiving bandwidth of the receiving channel of the antenna array to be tested.

4. The unit-level digital spherical conformal antenna array gain test method according to claim 3, characterized in that: In step S4, the signal-to-noise ratio SNR after receiving and processing by the array antenna is calculated. o_dB , specifically including the following sub-steps: When the test signal is not radiated, collect N noise time domain points n1....n i , after radiating the test signal, collect N signal plus noise time domain points a1...a i , calculate the output signal-to-noise ratio SNR according to the following formula o_dB :

5. The unit-level digital spherical conformal antenna array gain test method according to claim 4, characterized in that: In step S5, the SNR i_dB and SNR o_dB , calculate the array gain G dB , specifically including the following sub-steps: SNR i_dB and SNR o_dB Substitute the following formula to calculate the array gain G dB : G dB =NF dB +SNR o_dB -SNR i_dB ; Among them, NF dB is the noise coefficient, which is an inherent characteristic of the channel.

6. The unit-level digital spherical conformal antenna array gain test method according to claim 1, characterized in that: The antenna includes an L-band antenna.

7. The unit-level digital spherical conformal antenna array gain test method according to claim 1, characterized in that: The array comprises a 512-element array.

8. The unit-level digital spherical conformal antenna array gain test method according to claim 1, characterized in that: The number of the measured frequency points includes 3, and the elevation angles relative to the center of the antenna array are 0°, 10° and 30° respectively.

9. A unit-level digital spherical conformal antenna array gain test device, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is loaded by the processor, the method according to any one of claims 1 to 8 is executed.

10. A unit-level digital spherical conformal antenna array gain test system, characterized in that: Comprising the device as claimed in claim 9.

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