Test system and test method

Abstract

The present invention provides a test system and a test method for performing a wireless test on a device under test (500) to obtain electromagnetic radiation performance. The test system includes a support table (100) for supporting the device under test, a plurality of test antennas (200), and a moving mechanism including at least two moving units (300). Each moving unit (300) is provided with a test antenna (200), and the test antennas (200) are arranged to have a predetermined angular interval with respect to the support table (100). The moving mechanism further includes a driving unit for driving the moving unit (300) so that the test antennas (200) reach a plurality of sampling points (600). The sampling points (600) are located at a plurality of different angles with respect to the support table (100), and the angular intervals of the sampling points (600) with respect to the support table (100) are smaller than the predetermined angular intervals.

Description

Technical Field

[0001] The present invention relates to the field of communication tests, and more particularly to a test system and a test method for obtaining electromagnetic radiation performance by performing wireless tests on a device under test.

Background Art

[0002] In related technologies, test systems for antennas and wireless devices can be classified into single-probe test systems and multi-probe test systems according to the number of test antennas. A single-probe test system has only one test antenna. To achieve sampling at different azimuth and elevation angles of the device under test, one implementation method is to fix the test antenna and control the two-dimensional rotation of the device under test, and another implementation method is to control the test antenna and move the device under test in the elevation angle direction in accordance with the one-dimensional rotation of the device under test in the horizontal direction. In a multi-probe test system, usually, a plurality of test antennas are fixedly arranged around the device under test, and electromagnetic performance sampling can be realized from all angles only by the one-dimensional rotation of the device under test during the test.

[0003] The single-probe test system has a simple structure, but to achieve sampling at different spatial positions, it is necessary to move and rotate the test antenna or the device under test multiple times, resulting in a long test time. The multi-probe test system can quickly switch each test antenna through an electronic switch, and has high test efficiency. However, there is coupling (interference) between adjacent test antennas. Especially in the case of high-resolution sampling, the distance between test antennas is small and the coupling interference is stronger, which affects the test accuracy.

Summary of the Invention

[0004] The present invention primarily provides a test system and test method for obtaining electromagnetic radiation performance by performing wireless tests on a device under test. The device under test is an antenna or a wireless device having an antenna.

[0005] According to a first embodiment of the present invention, a test system is provided comprising a support base, a plurality of test antennas, and a moving mechanism. The support base is used to support the device under test. The moving mechanism includes at least two moving units, each of which is fitted with a test antenna, which are positioned at a predetermined angular interval with respect to the support base. The moving mechanism further includes a drive unit for driving the moving units so that the test antennas reach a plurality of sampling points. The sampling points are located at a plurality of different angles with respect to the support base, and the angular interval of the sampling points with respect to the support base is smaller than the predetermined angular interval.

[0006] According to one embodiment of the test system, the number of mobile units is equal to the number of test antennas, with one test antenna attached to each mobile unit.

[0007] According to one embodiment of the test system, a tester for performing sampling when the test antenna reaches the sampling point is further included.

[0008] According to one embodiment of the test system, the distance between adjacent test antennas is greater than half the wavelength corresponding to the test frequency.

[0009] According to one embodiment of the test system, the moving mechanism includes a guide rail, and the moving unit is a slider that can move along the guide rail.

[0010] According to one embodiment of the test system, the support base is a one-dimensional rotating platform.

[0011] According to one embodiment of the test system, one of the mobile units is equipped with a high-frequency switch (RF switch) connected to all the test antennas.

[0012] According to one embodiment of the test system, a high-frequency switch is installed in each mobile unit, and each high-frequency switch is connected to a test antenna in the corresponding mobile unit.

[0013] A second embodiment of the present invention provides a test method. The method includes the steps of: placing a device under test on a support stand; dividing a plurality of test antennas into at least two groups and attaching the test antennas of each group to a mobile unit, wherein the test antennas are positioned at a predetermined angular interval with respect to the support stand; and driving the mobile unit so that the test antennas reach a plurality of sampling points and perform sampling, wherein the sampling points are located at a plurality of different angles with respect to the support stand, and the angular interval of the sampling points with respect to the support stand is smaller than the predetermined angular interval of the test antennas.

[0014] According to one embodiment of the test method, the distance between adjacent test antennas is made greater than half the wavelength corresponding to the test frequency. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram of a single-probe test system in related technologies. [Figure 2] This is a schematic diagram of a single-probe test system in related technologies. [Figure 3] This is a schematic diagram of a single-probe test system in related technologies. [Figure 4] This is a schematic diagram of a multi-probe testing system in related technologies. [Figure 5] This is a schematic diagram of a test system according to one embodiment of the present invention. [Figure 6]This is a schematic diagram of a test system according to one embodiment of the present invention. [Figure 7] This is a flowchart of a test method according to one embodiment of the present invention. [Modes for carrying out the invention]

[0016] Embodiments of the present invention will be described below with reference to the drawings. Please note that the drawings are not necessarily to the same scale. The embodiments described are illustrative and are not intended to limit the present invention, and may be combined or replaced with the features of the embodiments in the same or similar manner. As used in the present invention and the appended claims, the singular forms “one kind,” “the said,” and “the said” include the plural unless the context clearly indicates otherwise. Furthermore, as used herein, the term “and / or” means any one or more of the listed related items or any possible combination thereof, and should be understood to include them.

[0017] In related technologies, test systems for antennas and wireless devices can be classified into single-probe and multi-probe systems depending on the number of test antennas. A single-probe system has only one test antenna, and in order to achieve sampling at different azimuth and elevation angles of the device under test, one method is to hold the test antenna still and control the device under test to rotate in two dimensions, and another method is to control the test antenna and move it in the elevation direction of the device under test in accordance with the device's one-dimensional horizontal rotation. In a multi-probe system, multiple test antennas are usually fixedly positioned around the device under test, and electromagnetic performance sampling can be achieved from any angle simply by rotating the device under test in one dimension during testing. Both single-probe and multi-probe systems have their own advantages and disadvantages.

[0018] For large antennas or large devices under test such as vehicles and aircraft, achieving two-dimensional rotation of the device itself is difficult. In wireless testing technologies, it is common to either hold the device under test still or rotate it horizontally in one dimension. As an example, a single-probe test system in related technologies is shown in Figures 1-3. In a single-probe test system, a single test antenna 200 is used to test the device under test 500. The test antenna 200 moves in an arc in the direction of the elevation angle of the device under test 500. The dashed line L shows the movement trajectory of the test antenna 200. If a spherical coordinate system is constructed with the center of the device under test 500 as the origin, the range of movement of the test antenna 200 in the elevation direction of the device under test 500 is 180°. The movement of the test antenna 200 is linked to a 180° one-dimensional rotation of the device under test 500 in the horizontal direction, realizing a sampling test of the upper hemisphere of the device under test 500. Figures 2 and 3 show the test antenna 200 positioned at the two endpoints of its movement trajectory L, respectively. As can be seen, the range of movement of the test antenna 200 is very wide, which causes the high-frequency cable (RF cable) 201 connecting the test antenna 200 and the test equipment 600 to repeatedly move and bend over a wide range. When the RF cable bends, the stability of its phase and amplitude decreases, which may affect the accuracy of the test. In addition, after a certain period of use, the RF cable may experience performance failure due to mechanical fatigue. On the other hand, as another example, a multi-probe test system in a related technology is shown in Figure 4. In a multi-probe test system, the device under test 500 is tested using multiple test antennas 200. In this example, the multiple test antennas 200 are fixedly arranged on an arc-shaped antenna rack centered on the device under test 500, and the test antennas 200 are positioned in the elevation direction of the device under test 500 in the range of 0° to 90°. The arrangement density of the test antennas 200 is the sampling resolution in the elevation direction of the device under test 500, and by matching the 360° one-dimensional rotation of the device under test 500 itself in the horizontal direction, sampling tests of the upper hemisphere of the device under test 500 can be realized.In this test system, since the test antenna is fixed so as not to move, repeated bending of the high-frequency cable is avoided. However, there is coupling interference between adjacent test antennas. Especially when the sampling resolution is high, the distance between the test antennas is narrow and the coupling interference is stronger, which has an adverse effect on the test accuracy.

[0019] Based on the above findings, in order to overcome the above-mentioned technical problems to a certain extent, the present invention provides a test system and a test method.

[0020] <Embodiment 1> Please refer to FIGS. 5 and 6. The present invention provides a test system including a support base 100, nine test antennas 200, and a moving mechanism. Each part will be described in detail below.

[0021] The support base 100 is used to support the device under test 500.

[0022] The moving mechanism includes three moving units 300. Three test antennas 200 are attached to each of the moving units 300, and the test antennas 200 are arranged so as to have a predetermined angular interval of 20° with respect to the support base 100.

[0023] The moving mechanism further includes a drive unit (not shown) for driving the moving unit 300 to move along a predetermined trajectory so that the test antenna 200 attached to the moving unit 300 can reach multiple sampling points 600. The multiple sampling points 600 are located at multiple different angles with respect to the support base 100, and the angular spacing between sampling points 600 (with respect to the support base 100) is smaller than the predetermined angular spacing between test antennas 200 (with respect to the support base 100). As a specific example, the sampling points 600 shown in Figure 6 are arranged at equal angular intervals, and the angular spacing between adjacent sampling points 600 with respect to the support base 100 is 5°. This is smaller than the predetermined angular spacing of 20° between adjacent test antennas 200 with respect to the support base 100. In this example, it can be seen that if the moving unit 300 has an elevation range of 15° with respect to the support base 100, the test antenna 200 within the moving unit 300 can reach three sampling points 600 between adjacent test antennas 200. The three test antennas 200 within each mobile unit 300 move synchronously, but different mobile units 300 may move independently of each other or simultaneously, and it can be understood that this can be flexibly configured according to the needs of the test. The mobile mechanism can use mechanical devices from the prior art to achieve the above functions. In Embodiment 1, the mobile mechanism includes a guide rail 400. The mobile unit 300 is a slider that can move along the guide rail 400, and a drive unit provides power for the movement of the mobile unit 300.

[0024] In the test system of Embodiment 1, multiple test antennas are used that are spaced far apart to reduce coupling interference caused by the distance between test antennas being too close. Here, "spaced far apart" means in relation to the sampling resolution. Theoretically, by moving the mobile unit, the test antennas can reach any angular position between adjacent test antennas, thereby achieving higher resolution sampling. In Embodiment 1, multiple test antennas are used for movement and sampling, and the range of movement of the test antennas is much smaller than when sampling is performed using a single antenna, so it can be seen that problems caused by bending of high-frequency cables are greatly reduced, and both test efficiency and test accuracy are taken into consideration. In addition, in the test system of Embodiment 1, since each test antenna is installed on a different mobile unit, multiple test antennas can be moved in groups, which brings about the following beneficial effects: 1. In some test scenarios of large devices under test, the test antennas are large and heavy, and the sampling range to be performed is also wide. Moving multiple test antennas as a whole places a heavy load on the system and requires a high-performance drive mechanism; therefore, assigning multiple test antennas to different moving units is a good solution. 2. By individually controlling the operation of each group of test antennas, at least some of the operation of the test antennas is performed independently of each other, making the test system suitable for a wider range of test scenarios. For example, if it is only necessary to measure the radiation characteristics of a localized area of ​​the device under test, only one or more of the moving units can be used. For example, if sampling needs to be performed at different resolutions in different areas of the sampling plane, the moving units for the corresponding areas can be individually controlled to perform different movements and sampling in those areas.As another example, when testing the MIMO (Multiple Input, Multiple Output) performance of a device under test using the Radiated Two-stage (RTS) method in the related art, the independent movement between the test antennas contributes to quickly achieving an air transmission matrix with high isolation.

[0025] In the test system of the present invention, as a special example, the number of moving units is equal to the number of test antennas, and one test antenna is attached to each moving unit. Correspondingly, each moving unit can be controlled to move the test antennas independently of each other, or all the moving units can be controlled to move the test antennas simultaneously. This is suitable for test scenarios where the test antennas are larger and heavier, or where a wider sampling range needs to be executed. Also, the independence between the test antennas is enhanced and the utilization becomes more flexible.

[0026] The connection method between the test antenna and the high-frequency switch includes two alternative methods, but is not limited thereto. One method is to attach one high-frequency switch to one of the moving units, connect all the test antennas to the high-frequency switch, and connect the other end of the high-frequency switch to the tester via a high-frequency cable. Another method is to attach one high-frequency switch to each moving unit, connect the test antennas attached within each moving unit to the high-frequency switch, and connect the other end of the high-frequency switch to the tester via a high-frequency cable.

[0027] It should be understood that the predetermined angular interval between the test antennas with respect to the support base mentioned in the present invention represents the angular interval between the test antennas within a single moving unit. This is because the relative positions between the test antennas within the moving unit are fixed, but the relative positions of the test antennas between each moving unit are not fixed.

[0028] Embodiment 1 provides only one specific example, and in the present invention, the number of mobile units (i.e., the number of groups of test antennas) may be set according to the actual situation, such as the sampling accuracy, the test content, the number and weight of the test antennas, and the driving capacity of the drive unit. The number of test antennas attached to each mobile unit may be the same or different. The predetermined angular spacing between the test antennas may be equal or unequal. That is, the test antennas may be evenly or unevenly arranged.

[0029] Furthermore, it should be explained that in this invention, when describing spatial relationships with respect to the support base (such as "a predetermined angular interval between test antennas with respect to the support base" or "sampling points at multiple different angular positions with respect to the support base"), the position of the support base should be understood as a single point, or more specifically, the center point of the test. For example, in spherical scanning, the position of the support base may be considered as the center of the spherical scan, that is, the center of the device under test.

[0030] Selectively, the test system further includes a test instrument for performing sampling when the test antenna reaches the sampling point. The test instrument is, for example, at least one of the following in the relevant art: a vector network analyzer, a vector signal analyzer, a spectrum analyzer, an oscilloscope, or a signal generator.

[0031] Please refer to Figure 5 for this selective method. In order to control the coupling interference between test antennas 200 within a certain level, the test antennas 200 may be set such that the distance S between adjacent test antennas 200 is greater than half the wavelength corresponding to the test frequency. By setting this spacing distance, the coupling interference between test antennas 200 can be controlled to a generally acceptable level. For example, if the test frequency is 600 MHz and the wavelength is 50 cm, then the test antennas 200 need to be set such that the distance S between adjacent test antennas 200 is greater than 25 cm.

[0032] In Embodiment 1, the test antennas are arranged in an arc shape with the support base as the center, allowing for arc-shaped sampling on a single cross-section in the elevation direction of the device under test. To further obtain spherical scanning of the device under test, one implementation is to control the device under test to rotate in the azimuth direction. Specifically, for example, the support base is a one-dimensional rotating platform used to support the device under test and rotate it in one dimension in the horizontal plane. Another implementation is for multiple test antennas to surround the device under test as a whole and move in the horizontal plane. Specifically, for example, multiple test antennas are mounted on a movable platform that can move around the device under test.

[0033] It should be noted that the present invention is not limited to use in spherical scanning, but is also applicable to other scanning methods such as planar scanning.

[0034] <Embodiment 2> Similar to the test system described above, the present invention provides a test method. Referring to Figure 7, the test method in the embodiment is: Step S1 involves placing the device under test on a support stand, Step S2 involves dividing multiple test antennas into at least two groups and attaching the test antennas of each group to one mobile unit, wherein the test antennas are positioned so as to have a predetermined angular distance from the support base. Step S3 includes driving a mobile unit so that a test antenna reaches multiple sampling points and performs sampling, wherein the sampling points are located at multiple different angles with respect to a support base, and the angular spacing between the sampling points with respect to the support base is smaller than the predetermined angular spacing described above. Selectively, the distance between adjacent test antennas is greater than half the wavelength corresponding to the test frequency.

[0035] In the test method of the present invention, the order in which steps S1 and S2 are performed is not limited; step S2 may be performed first, followed by step S1. For a description of the technical details included in the test method, please refer to the above description of the test system, as the description is omitted here.

[0036] Please note that all figures in this invention are simplified schematic diagrams and are used only to provide a general overview of the positional and connection relationships between the components in the embodiments.

[0037] In the above description, reference terms such as "one embodiment," "several embodiments," "example," "specific example," or "several examples" mean that the specific features, structures, materials, or properties described in accordance with the embodiment or example are included in at least one embodiment or example of the present invention. In the present invention, the general expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or properties described can be combined in an appropriate manner in one or more embodiments or examples.

[0038] Furthermore, the terms “first” and “second” are used solely for descriptive purposes and are not intended to indicate or imply relative importance, or to implicitly specify the number of technical features described. Accordingly, features designated as “first” and “second” may explicitly or implicitly include at least one such feature. In the description of this invention, “multiple” means at least two, such as two, three, etc., unless otherwise clearly and specifically limited.

[0039] Although embodiments of the present invention have been shown and described above, these embodiments are illustrative and should not be construed as limiting the present invention. Those skilled in the art should understand that changes, modifications, substitutions, and variations of the above embodiments can be made within the scope of the present invention.

Claims

1. A test system for obtaining electromagnetic radiation performance by performing wireless tests on a device under test having a radiating antenna, comprising a support stand, multiple test antennas for receiving, and a mobile mechanism, The support stand is used to support the device under test. The moving mechanism includes at least two moving units, each of which is fitted with the test antenna, and the test antennas within each moving unit are arranged at a predetermined angular distance from the support base. The moving mechanism further includes a drive unit for driving the moving unit so that the test antenna reaches a plurality of sampling points, wherein the sampling points are located at a plurality of different angles with respect to the support base, and the angular interval of the sampling points with respect to the support base is smaller than the predetermined angular interval. Each mobile unit is equipped with at least two of the aforementioned test antennas, and at least two of the aforementioned test antennas attached to the same mobile unit can move in sync, while different mobile units can move independently of each other. A test system characterized in that the distance between adjacent test antennas is greater than half the wavelength corresponding to the test frequency, a high-frequency switch is installed in each of the mobile units, and each high-frequency switch is connected to the test antenna in the corresponding mobile unit.

2. The test system according to claim 1, further comprising a tester for performing sampling when the test antenna reaches the sampling point.

3. The test system according to claim 1, characterized in that the moving mechanism includes a guide rail, and the moving unit is a slider that can move along the guide rail.

4. The test system according to claim 1, characterized in that the support base is a one-dimensional rotating platform.

5. The test system according to claim 1, characterized in that one of the mobile units is fitted with a high-frequency switch connected to all of the test antennas.

6. A test method for obtaining electromagnetic radiation performance by performing a wireless test on a device under test that has a radiating antenna, The steps include: placing the device under test on a support stand, The steps include dividing a plurality of receiving test antennas into at least two groups, and attaching the test antennas of each group to at least two mobile units, wherein the test antennas are positioned within each mobile unit at a predetermined angular distance from the support base, A step of driving the mobile unit so that the test antenna reaches a plurality of sampling points and performs sampling, the step of the sampling points being located at a plurality of different angles with respect to the support base, and the angular interval between the sampling points with respect to the support base being smaller than a predetermined angular interval, Each mobile unit is equipped with at least two of the aforementioned test antennas, and at least two of the aforementioned test antennas attached to the same mobile unit can move in sync, while different mobile units can move independently of each other. A test method characterized in that the distance between adjacent test antennas is greater than half the wavelength corresponding to the test frequency, a high-frequency switch is installed in each of the mobile units, and each high-frequency switch is connected to the test antenna in the corresponding mobile unit.

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