Antenna pattern near-field test method and system based on linear scanning

Abstract

The invention relates to the technical field of antennas, in particular to an antenna pattern near-field test method and system based on linear scanning. The embodiment of the invention provides an antenna pattern near-field test method based on linear scanning, and the method comprises the steps: moving a receiving and transmitting antenna along a preset straight line, and transmitting and receiving electromagnetic waves at the same time; receiving echo level data of the test target at different positions of the transceiving antenna; determining the shortest distance between the transceiving antenna and the test target according to the echo level data; compensating the echo power obtained at different positions by taking the shortest distance as a standard, so that the echo power collected at different positions is compensated to be compensation power at the same distance from the test target and at different angles; and generating antenna directional diagrams with the same test distance and different test angles according to the compensation level data. The embodiment of the invention provides an antenna directional diagram near-field test method and system based on linear scanning, and the method and system can obtain a dual-antenna directional diagram.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a near-field testing method and system for antenna patterns based on linear scanning. Background Art

[0002] The antenna pattern is an important parameter of the antenna. It can directly reflect the important performance of the antenna gain distribution with angle. Therefore, it is very important to draw the antenna pattern of different frequency bands. The antenna pattern will be measured and a report will be provided before it leaves the factory. For the application of the receive / transmit dual antenna mode, in addition to the separate transmission and reception, there will also be vertical and horizontal station layouts and polarization matrices. In fact, the equivalent pattern of the dual antenna is somewhat different from that of the single antenna. Therefore, the antenna pattern of a single antenna will introduce certain errors when used in near-field measurements, so it is necessary to map the pattern of the dual antenna mode to effectively support related research. Summary of the invention

[0003] The embodiment of the present invention provides a method and system for near-field testing of antenna patterns based on linear scanning, which can obtain equivalent patterns of dual antennas.

[0004] An embodiment of the present invention provides a method for near-field testing of an antenna pattern based on linear scanning, comprising:

[0005] Move the transceiver antenna along a preset straight line to transmit and receive electromagnetic waves simultaneously;

[0006] Receiving echo level data of a test target at different positions of the transceiver antenna;

[0007] determining the shortest distance between the transceiver antenna and the test target based on the echo level data;

[0008] Taking the shortest distance as a standard, the echo powers obtained at different positions are compensated so that the echo powers collected at different positions are compensated powers at different angles at the same distance from the test target;

[0009] The antenna radiation pattern at the same test distance and different test angles is generated according to the compensation level data.

[0010] In a possible design, determining the shortest distance between a preset straight line and the test target according to the echo level data includes:

[0011] Performing one-dimensional range image processing on the echo level data to obtain a one-dimensional range image including distance and amplitude;

[0012] By performing software time-domain gate interception on the one-dimensional range image, the target part of a set of data is extracted to obtain the current state target data;

[0013] Based on the target data, a single straight line measurement data is used as a group of data to batch generate distance amplitude images;

[0014] The distance where the amplitude peak in the distance amplitude image is located is determined as the shortest distance.

[0015] In a possible design, the echo power obtained at different positions is compensated based on the shortest distance, so that the echo power collected at different positions is compensated for at different angles at the same distance from the test target, including:

[0016] Taking the echo power at the shortest distance as the standard power, calculating the error ratio between the echo power and the standard power at other distances;

[0017] The echo powers at other distances are compensated according to the error ratio to obtain compensated power.

[0018] In one possible design, the error ratio is calculated by the following formula:

[0019]

[0020] Where K is the error ratio, P x is the theoretical echo power at other distances, P0 is the standard power, R0 is the shortest distance, R x is the distance between the transmitting and receiving antennas and the test target, L x is the distance between the current transceiver antenna and the transceiver origin; where the transceiver origin is the position when the distance between the transceiver antenna and the test target is the shortest.

[0021] In a possible design, the compensation power is calculated by the following formula:

[0022]

[0023] Among them, P xs To compensate the power, P xc is the echo power.

[0024] In a possible design, the test target is a metal ball.

[0025] In one possible design, the method is used to test the directional patterns of the transceiver antennas when they are arranged horizontally, vertically, and at different polarizations.

[0026] In the second aspect, an embodiment of the present invention further provides an antenna pattern near-field test system based on linear scanning, which is used to implement any of the above methods, wherein the system includes a horizontal track, a vertical track, a transceiver antenna and the test target, wherein the vertical track is vertically arranged on the horizontal track and can slide along the horizontal track, and the transceiver antenna is arranged on the vertical track, and the station layout is changed by rotating the transceiver antenna.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] In this embodiment, while the transceiver antenna is moved in a straight line, the transceiver antenna continuously transmits and receives signals. When the transceiver antenna moves to different positions, it continuously receives echo signals of the test target and obtains echo level data. According to the received echo level data, the shortest distance between the transceiver antenna and the test target can be determined. Since the transceiver antenna moves in a straight line, the azimuth angle between the transceiver antenna and the test target will change during the movement. However, the position between the transceiver antenna and the test target is also changing. If a directional pattern is to be generated, the azimuth angle needs to change while the distance is constant. Therefore, the echo power obtained at other positions needs to be compensated according to the shortest distance and the current transceiver antenna position. After compensation, the compensated power is obtained, and the directional pattern can be generated according to the compensated power. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1a is a measured echo distribution diagram provided by an embodiment of the present invention;

[0031] Figure 1b is a distance compensation echo distribution diagram provided by an embodiment of the present invention;

[0032] Figure 2a is an echo accumulation distribution diagram provided by an embodiment of the present invention;

[0033] Figure 2b is an echo accumulation slope distribution diagram provided by an embodiment of the present invention;

[0034] Figure 3 is a schematic diagram of a horizontal plane scanning frame provided by an embodiment of the present invention;

[0035] Figure 4is a schematic diagram of a vertical scanning frame provided by an embodiment of the present invention;

[0036] Figure 5 is a schematic diagram of one-dimensional range image target extraction provided by an embodiment of the present invention;

[0037] Figure 6 is a distance amplitude image provided by an embodiment of the present invention;

[0038] Figure 7 is a schematic diagram of a test process provided by an embodiment of the present invention;

[0039] Figure 8 It is another schematic diagram of a testing process provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0041] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance; unless otherwise specified or explained, the term "multiple" refers to two or more; the terms "connected" and "fixed" should be understood in a broad sense, for example, "connected" can be a fixed connection, a detachable connection, an integral connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In the description of this specification, it should be understood that the directional words such as "upper" and "lower" described in the embodiments of the present invention are described at the angles shown in the drawings and should not be understood as limiting the embodiments of the present invention. In addition, in the context, it should also be understood that when it is mentioned that an element is connected to another element "upper" or "lower", it can not only be directly connected to another element "upper" or "lower", but also indirectly connected to another element "upper" or "lower" through an intermediate element.

[0043] An embodiment of the present invention provides a method for near-field testing of an antenna pattern based on linear scanning, comprising:

[0044] Move the transceiver antenna along a preset straight line to transmit and receive electromagnetic waves simultaneously;

[0045] Receive the echo level data of the test target at different positions of the transceiver antenna;

[0046] Determine the shortest distance between the transceiver antenna and the test target based on the echo level data;

[0047] Taking the shortest distance as the standard, the echo power obtained at different positions is compensated so that the echo power collected at different positions is compensated for the power at different angles at the same distance from the test target;

[0048] Generate antenna radiation patterns at the same test distance and different test angles as the compensation level data.

[0049] In this embodiment, while the transceiver antenna is moved in a straight line, the transceiver antenna continuously transmits and receives signals. In the process of the transceiver antenna moving to different positions, it continuously receives the echo signal of the test target and obtains the echo level data. According to the received echo level data, the shortest distance between the transceiver antenna and the test target can be determined. Please refer to Figure 1. Since the transceiver antenna moves in a straight line, the azimuth angle between it and the test target will change during the movement. However, the position between the transceiver antenna and the test target is also changing. If a directional pattern is to be generated, the azimuth angle needs to change while the distance is constant. Therefore, it is necessary to compensate the echo power obtained at other positions according to the shortest distance and the current transceiver antenna position. After compensation, the compensated power is obtained, and the directional pattern can be generated according to the compensated power.

[0050] Take the ground environment as an example. Antenna radiation is invisible to the naked eye, and the irradiated area of ​​the ground environment cannot be accurately measured. Therefore, the corresponding area is calculated through the dual-antenna equivalent antenna pattern. First, the pattern echo energy can be accumulated. As shown in Figure 2, as the angle increases, the curve approaches a constant and the slope decreases. The angle used for the test can be determined according to the test requirements. The same method can be used to obtain the antenna radiation angle under the HH / VV polarization of the antenna.

[0051] It is understandable that the present invention uses the radar system as the core to build an RCS measurement system. After the horizontal / vertical scanning system is built, the device is turned on and preheated until the system is stable, and the relevant frequency band and polarization settings are performed. Taking HH / VV polarization as an example, the HH polarization setting is performed first.

[0052] Horizontal layout of transmitting and receiving antennas (such as Figure 3 ), measure its horizontal plane pattern. After the measurement, keep the horizontal layout and rotate 90° (such as Figure 4 ) and measure its vertical plane pattern.

[0053] In some embodiments of the present invention, determining the shortest distance between a preset straight line and a test target according to the echo level data includes:

[0054] Performing one-dimensional range image processing on the echo level data to obtain a one-dimensional range image including distance and amplitude;

[0055] By performing software time-domain gate interception on the one-dimensional range image, the target part of a set of data is extracted to obtain the current state target data;

[0056] Based on the target data, a single straight line measurement data is used as a group of data to batch generate distance amplitude images;

[0057] The distance where the amplitude peak in the distance amplitude image is located is determined as the shortest distance.

[0058] In this embodiment, after the echo level data is obtained, a one-dimensional range image is processed to obtain a one-dimensional range image including distance and amplitude. In the one-dimensional range image, the peak part is the part with the largest amplitude, and the corresponding distance is the distance between the transceiver antenna and the test target. The amplitude and distance of the peak part are extracted ( Figure 5 ), and obtain the distance amplitude image ( Figure 6 ), the peak position with the strongest amplitude is the shortest distance between the transmitting and receiving antennas and the test target.

[0059] In some embodiments of the present invention, the echo power obtained at different positions is compensated based on the shortest distance, so that the echo power collected at different positions is compensated for the compensation power at different angles at the same distance from the test target, including:

[0060] Take the echo power at the shortest distance as the standard power, and calculate the error ratio between the echo power and the standard power at other distances;

[0061] The echo powers at other distances are compensated according to the error ratio to obtain the compensated power.

[0062] Please refer to Figure 7 In some embodiments of the present invention, the error ratio is calculated by the following formula:

[0063]

[0064] Where K is the error ratio, P x is the theoretical echo power at other distances, P0 is the standard power, R0 is the shortest distance, R x is the distance between the transmitting and receiving antennas and the test target, L x is the distance between the current transceiver antenna and the transceiver origin; where the transceiver origin is the position when the distance between the transceiver antenna and the test target is the shortest.

[0065] In some embodiments of the present invention, the compensation power is calculated by the following formula:

[0066]

[0067] Among them, P xs To compensate the power, P xc is the echo power.

[0068] It should be noted that P x P0 and P1 are theoretical values ​​calculated based on the distance between the transmitting and receiving wires and the test target. xc The actual value is obtained during the test, and the theoretical value is used to compensate the actual value.

[0069] It should be noted that the relationship between theoretical power and distance can be determined by the radar formula. Specifically, the radar formula is as follows:

[0070]

[0071] P t : Target echo;

[0072] P: electromagnetic system transmission power;

[0073] G: antenna gain;

[0074] λ: test wavelength;

[0075] R: distance between antenna and target;

[0076] δ t : Target electromagnetic scattering characteristics.

[0077] Since the electromagnetic scattering characteristics of the metal ball are isotropic, the target electromagnetic scattering characteristics δ, the stable electromagnetic transmission power P and the electromagnetic wave wavelength λ are all constants. At the same time, the position of the antenna facing the metal ball is selected as the antenna gain reference point, so the above factors are normalized. That is:

[0078]

[0079] The formula can be written as:

[0080]

[0081] In some embodiments of the present invention, the test target is a metal ball. In order to ensure that the target electromagnetic echo is isotropic, a metal ball is selected as the measurement target. After the metal ball is set up, the scanning frame is adjusted so that the center of the transceiver antenna is facing the metal ball. This is the horizontal scanning center position. Figure 8 As shown in the figure, synchronous acquisition is performed, and the metal ball echo is observed to be submerged in the background level, and the level distribution of more than half of the horizontal and vertical planes is obtained. Change the polarization combination to VV, and repeat the above steps to obtain the level distribution of more than half of the horizontal and vertical planes of its VV polarization.

[0082] In some embodiments of the present invention, the method is used to test the directional patterns of transceiver antennas when they are arranged horizontally, vertically, and at different polarizations.

[0083] An embodiment of the present invention also provides an antenna pattern near-field test system based on linear scanning, which is used to implement any of the above methods. The system includes a horizontal track, a vertical track, a transceiver antenna and a test target. The vertical track is vertically arranged on the horizontal track and can slide along the horizontal track. The transceiver antenna is arranged on the vertical track, and the station layout is changed by rotating the transceiver antenna.

[0084] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for near-field testing of antenna patterns based on linear scanning, characterized in that: include: Move the transceiver antenna along a preset straight line to transmit and receive electromagnetic waves simultaneously; Record and receive different positions of the transceiver antenna, and collect echo level data of the test target at the current position; determining the shortest distance between the transceiver antenna and the test target based on the echo level data; Taking the shortest distance as a standard, the echo powers obtained at different positions are compensated so that the echo powers collected at different positions are compensated powers at different angles at the same distance from the test target; The antenna radiation pattern at the same test distance and different test angles is generated according to the compensation level data.

2. The method according to claim 1, characterized in that The determining the shortest distance between a preset straight line and the test target according to the echo level data comprises: Performing one-dimensional range image processing on the echo level data to obtain a one-dimensional range image including distance and amplitude; By performing software time-domain gate interception on the one-dimensional range image, the target part of a set of data is extracted to obtain the current state target data; Based on the target data, a single straight line measurement data is used as a group of data to batch generate distance amplitude images; The distance where the amplitude peak in the distance amplitude image is located is determined as the shortest distance.

3. The method according to claim 1, characterized in that The method of compensating the echo powers obtained at different positions based on the shortest distance so that the echo powers collected at different positions are compensated powers at different angles at the same distance from the test target includes: Taking the echo power at the shortest distance as the standard power, calculating the error ratio between the echo power and the standard power at other distances; The echo powers at other distances are compensated according to the error ratio to obtain compensated power.

4. The method according to claim 3, characterized in that The error ratio is calculated by the following formula: Where K is the error ratio, P x is the theoretical echo power at other distances, P0 is the standard power, R0 is the shortest distance, R x is the distance between the transmitting and receiving antennas and the test target, L x is the distance between the current transceiver antenna and the transceiver origin; where the transceiver origin is the position when the distance between the transceiver antenna and the test target is the shortest.

5. The method according to claim 4, characterized in that The compensation power is calculated by the following formula: Among them, P xs To compensate the power, P xc is the echo power.

6. The method according to claim 1, characterized in that The test target is a metal ball.

7. The method according to claim 1, characterized in that The method is used to test the directional diagrams of the transceiver antennas when they are arranged horizontally, vertically and in different polarization combinations.

8. A near-field antenna pattern test system based on linear scanning, characterized in that: Used to implement any of the methods described in claims 1-7, the system includes a horizontal track, a vertical track, a transceiver antenna and the test target, the vertical track is perpendicular to the horizontal track and can slide along the horizontal track, the transceiver antenna is arranged on the vertical track, and the station layout is changed by rotating the transceiver antenna.

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