An all-electric anechoic chamber ripple test fixture

Abstract

The application provides a full-electric-wave anechoic chamber ripple test clamp, and belongs to the technical field of wireless communication detection. In order to solve the problem of inconvenient adjustment of the position of a detection antenna in the full-electric-wave anechoic chamber ripple test, the full-electric-wave anechoic chamber ripple test clamp comprises a fixed base (1), a supporting column (7) and an antenna fixing device. The antenna fixing device is detachably connected with the supporting column (7), and the antenna fixing device is a Φ-axis antenna fixing device (9) or a θ-axis antenna fixing device (10). The full-electric-wave anechoic chamber ripple test clamp can conveniently and accurately realize the movement of the detection antenna in six directions, so that the accurate positioning and rapid adjustment of the detection antenna at different stations can be realized, the test operation efficiency is significantly improved, and the labor and time costs are reduced.

Description

Technical Field

[0001] This invention relates to the field of wireless communication testing technology, specifically a full anechoic chamber ripple testing fixture. Background Technology

[0002] The core function of a fully anechoic chamber is to simulate an infinitely large, reflection-free free-space environment. The inner walls of the chamber are lined with absorbing materials to absorb electromagnetic waves and prevent reflection. Ripple testing is used to verify the quiet zone performance of the site and measure the performance changes caused by reflection within the fully anechoic chamber. The results describe the characteristics of the entire test system, including the locator and support structure, and are included in the total uncertainty of the entire test system after analysis. Therefore, ripple testing is a mandatory procedure in the acceptance testing of fully anechoic chambers. Furthermore, CNAS-CL01-A008:2023, "Application Instructions of Accreditation Criteria for Testing and Calibration Laboratories in the Field of Electromagnetic Compatibility Testing," clearly stipulates that ripple testing should be performed at least every 3-5 years, making it a necessary item for periodically verifying the performance of the anechoic chamber.

[0003] According to the CTIA (Communications and Internet Association) standard, ripple testing is divided into Φ-axis ripple testing and θ-axis ripple testing. For Φ-axis ripple testing, the quiet zone is a cylinder with a diameter of 300mm and a height of 300mm. The probe antenna is parallel to the Φ-axis, and 10 positions are measured. For θ-axis ripple testing, the quiet zone is a sphere with a diameter of 300mm. The probe antenna is parallel to the θ-axis, and 12 positions are measured. Each axis test requires a coaxial dipole probe antenna family (at least 9 antennas) and a standard ring probe antenna family (at least 9 antennas). This means the probe antennas move around the center of the anechoic chamber along the X, Y, and Z axes. The phase center positions of the probe antennas differ for different frequency bands, and the positions must be continuously adjusted during testing to ensure the phase center of the probe antenna is at the measurement position specified in the standard.

[0004] Currently, changes to the antenna's position are achieved manually by adding or removing supports at varying heights. These supports lack displacement measurement markings, requiring personnel to repeatedly measure and align the antenna with a laser positioning device each time, significantly increasing manpower and time costs. Furthermore, during low-frequency ripple testing, the relatively long dipole antenna and high phase center of the low-frequency band make it susceptible to phase center shift if the turntable rotates too quickly, leading to inaccurate test results. Additionally, when measuring the quiet zone boundary, the antenna risks falling from the turntable, potentially causing damage.

[0005] Glossary: A quiet zone is a pre-designed, finite spatial area within a fully anechoic chamber. Within this area, the electromagnetic environment is shaped to closely approximate an ideal free space, and its characteristics (such as field strength amplitude, phase, polarization, etc.) meet the specifications required for specific precision testing.

[0006] Ripple: In a specific test environment, due to the coherent interference between the direct wave and the reflected wave from the surrounding environment, the signal strength (field strength or power) measured in the spatial or angular domain exhibits undesirable periodic fluctuations or fluctuations.

[0007] Over-the-air (OTA) performance refers to the spatial radio frequency performance of wireless communication devices, including spatial radio frequency transmission and reception performance.

[0008] Anechoic chamber: A shielded room in which all surfaces of the interior walls (including the ceiling, floor and surrounding walls) are covered with highly efficient electromagnetic wave absorbing materials, designed to simulate free space conditions with no reflection and no interference.

[0009] Coaxial dipole detection antenna family: A family of antennas consisting of multiple coaxial dipole antennas, used to detect the electromagnetic field strength at a specific location in a fully anechoic chamber, and its frequency range can cover the frequency band required for anechoic chamber ripple testing.

[0010] Standard ring probe antenna family: A family of antennas consisting of multiple standard ring antennas, used to detect the electromagnetic field strength at a specific location in a fully anechoic chamber, with a frequency range that can cover the frequency band required for anechoic chamber ripple testing. Summary of the Invention

[0011] To address the problem of inconvenient antenna position adjustment in existing anechoic chamber ripple testing, this invention provides a anechoic chamber ripple testing fixture. This fixture allows for convenient and accurate movement of the antenna in six directions, enabling precise positioning and rapid adjustment of the antenna at different workstations, significantly improving testing efficiency and reducing labor and time costs.

[0012] The technical solution adopted by the embodiments of the present invention to solve its technical problem is as follows: A fully anechoic chamber ripple testing fixture, in a spatial rectangular coordinate system with X, Y, and Z axes as coordinate axes, includes a fixed base, a support column, and an antenna fixing device. The upper surface of the fixed base is provided with a positive sliding longitudinal axis, a negative sliding longitudinal axis, a positive sliding transverse axis, and a negative sliding transverse axis, which are arranged in a cross shape. The center lines of the positive and negative sliding longitudinal axes coincide and are both parallel to the X, Y, and Z axes. The center lines of the X-axis, the positive sliding horizontal axis, and the negative sliding horizontal axis coincide and are both parallel to the Y-axis. The center line of the support column is parallel to the Z-axis. A sliding base is provided at the lower end of the support column. The support column can move along the positive sliding vertical axis, the negative sliding vertical axis, the positive sliding horizontal axis, or the negative sliding horizontal axis with the sliding base. The antenna fixing device is detachably connected to the support column. The antenna fixing device can move along the center line of the support column. The antenna fixing device is a Φ-axis antenna fixing device or a θ-axis antenna fixing device.

[0013] The beneficial effects of the embodiments of the present invention are: 1. This fixture fills the current gap in the field of ripple testing fixtures.

[0014] 2. This fixture allows for flexible displacement of the probe antenna along the XYZ axes. It enables the probe antenna to correspond one-to-one with the position specified in the ripple test standard without the need for additional supports, thereby improving testing efficiency and saving time and effort.

[0015] 3. This fixture has a three-dimensional displacement measurement scale, which can achieve precise control of the position of the detection antenna in the X, Y and Z axes, effectively reducing test errors and improving the accuracy of the anechoic chamber system.

[0016] 4. This fixture can stably fix the detection antenna, reducing the shaking of the antenna phase center caused by the rotation of the turntable during the test, thereby reducing test errors and effectively avoiding antenna damage.

[0017] 5. This fixture has wide applicability and can flexibly adjust the placement angle and position of the antenna under test.

[0018] 6. This fixture is also suitable for testing passive antennas.

[0019] 7. This fixture can be combined in various ways, and is easy to assemble and disassemble, making it suitable for a variety of antennas under test. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0021] Figure 1This is a three-dimensional schematic diagram of the antenna fixing device in the all-anechoic chamber ripple test fixture of the present invention when it is a Φ-axis antenna fixing device.

[0022] Figure 2 This is a three-dimensional schematic diagram of the antenna fixing device in the all-anechoic chamber ripple test fixture of the present invention when it is a θ-axis antenna fixing device.

[0023] Figure 3 This is a top view of the fixed base.

[0024] Figure 4 This is a schematic diagram showing the connection between the sliding base and the support column.

[0025] Figure 5 This is a schematic diagram of the connection between the Φ-axis antenna fixing device and the support column.

[0026] Figure 6 This is a three-dimensional schematic diagram of the Φ-axis antenna mounting device.

[0027] Figure 7 This is an exploded view of the Φ-axis antenna mounting device.

[0028] Figure 8 This is a top view of the Φ-axis antenna mounting device.

[0029] Figure 9 This is a schematic diagram of the connection between the θ-axis antenna fixing device and the support column.

[0030] Figure 10 This is a three-dimensional schematic diagram of the θ-axis antenna mounting device.

[0031] Figure 11 This is a top view of the θ-axis antenna mounting device.

[0032] The annotations in the attached figures are explained as follows: 1. Fixed base; 2. Positive sliding longitudinal axis; 3. Negative sliding longitudinal axis; 4. Positive sliding transverse axis; 5. Negative sliding transverse axis; 6. Sliding base; 7. Support column; 8. First positioning screw; 9. Φ-axis antenna fixing device; 10. θ-axis antenna fixing device; 11. First rotating bracket; 12. First connector; 13. Fixing sleeve; 14. Second positioning screw; 15. Insertion support column; 16. Third positioning screw; 17. Second rotating bracket; 18. Second connector; 19. Fixing groove; 20. Fourth positioning screw; 21. Insertion pipe joint; 22. Fifth positioning screw; 23. First length measurement scale; 24. Second length measurement scale; 25. Third length measurement scale; 101. Base through hole; 601. Slide groove; 602. Positioning mark line; 1301. Internal through hole; 1501. First antenna mounting cavity; 1502. Support sidewall; 1503. Large diameter section; 1504. Small diameter section; 1901. Installation groove; 1902. Curve; 2101. The inner cavity for the second antenna installation; 2102. The side wall of the pipe section. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] For ease of understanding and description, the following description of the present invention uses a combination of absolute positional relationships and a spatial rectangular coordinate system. Unless otherwise specified, the directional term "above" indicates perpendicular to. Figure 3 The direction pointed outwards from the paper and corresponds to the positive direction of the Z-axis. The directional word "down" indicates perpendicular to the Z-axis. Figure 3 The direction pointing inwards from the paper and corresponding to the negative direction of the Z-axis is indicated by the directional term "left". Figure 3 The left direction in the middle, corresponding to the negative direction of the Y-axis, the directional word "right" indicates... Figure 3 The right-hand direction, corresponding to the positive direction of the Y-axis, is indicated by the directional term "front". Figure 3 The upper direction in the middle, corresponding to the negative direction of the X-axis, the directional word "back" indicates Figure 3 The orientation is located on the lower side and corresponds to the positive direction of the X-axis. This invention is described from the perspective of the reader or user, but the aforementioned directional terms should not be construed as limiting the scope of protection of this invention. Regarding the material, weight, size, angle, and parameters of the components, those skilled in the art can determine or replace them according to actual needs or a limited number of experiments.

[0035] In this embodiment, as Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, in a spatial rectangular coordinate system with the X-axis, Y-axis, and Z-axis as coordinate axes, the ripple test fixture for the anechoic chamber includes a fixed base 1, a support column 7, and an antenna fixing device. The upper surface of the fixed base 1 is provided with a positive sliding vertical axis 2, a negative sliding vertical axis 3, a positive sliding horizontal axis 4, and a negative sliding horizontal axis 5. These axes are arranged in a cross shape. The centerline of the positive sliding vertical axis 2 coincides with the centerline of the negative sliding vertical axis 3 and is parallel to the X-axis. The centerline of the positive sliding horizontal axis 4 coincides with the centerline of the negative sliding vertical axis 5. The center lines of the horizontal axis 5 coincide and are parallel to the Y-axis. The center line of the support column 7 is parallel to the Z-axis. A sliding base 6 is provided at the lower end of the support column 7. The support column 7 can move along the positive sliding vertical axis 2, the negative sliding vertical axis 3, the positive sliding horizontal axis 4, or the negative sliding horizontal axis 5 with the sliding base 6. The antenna fixing device is detachably connected to the support column 7. The antenna fixing device can move along the extension direction of the center line of the support column 7. The antenna fixing device is a Φ-axis antenna fixing device 9 or a θ-axis antenna fixing device 10. The antenna fixing device can install and fix the detection antenna.

[0036] The fixed base 1 is a circular plate structure with a diameter of 760mm. The fixed base 1 is parallel to the horizontal plane, and the upper surface of the fixed base 1 is parallel to the plane containing the X-axis and Y-axis. The positive sliding longitudinal axis 2 can be called the positive sliding longitudinal track, the negative sliding longitudinal axis 3 can be called the negative sliding longitudinal track, the positive sliding transverse axis 4 can be called the positive sliding transverse track, and the negative sliding transverse axis 5 can be called the negative sliding transverse track.

[0037] like Figure 1 , Figure 2 , Figure 3 , Figure 4 As shown, the positive sliding vertical axis 2 and the negative sliding vertical axis 3 are spaced apart along the X-axis direction, with a distance of 60mm between them. The positive sliding horizontal axis 4 and the negative sliding horizontal axis 5 are spaced apart along the Y-axis direction, with a distance of 60mm between them. The spaced portion between the positive sliding vertical axis 2 and the negative sliding vertical axis 3 partially overlaps with the spaced portion between the positive sliding horizontal axis 4 and the negative sliding horizontal axis 5. The sliding base 6 can reciprocate between the positive sliding vertical axis 2 and the negative sliding vertical axis 3, and it can also reciprocate between the positive sliding horizontal axis 4 and the negative sliding horizontal axis 5.

[0038] Both the positive sliding vertical axis 2 and the negative sliding vertical axis 3 are provided with a first length measurement scale 23. The measurement direction of the first length measurement scale 23 is parallel to the X-axis. The projection of the center line of the positive sliding vertical axis 2 onto the upper surface of the fixed base 1 passes through the center of the upper surface of the fixed base 1. Both the positive sliding horizontal axis 4 and the negative sliding horizontal axis 5 are provided with a second length measurement scale 24. The measurement direction of the second length measurement scale 24 is parallel to the Y-axis. The distance between the projection of the center line of the positive sliding horizontal axis 4 onto the upper surface of the fixed base 1 and the center of the upper surface of the fixed base 1 is equal to the antenna setting offset distance L (e.g., 100mm). This antenna setting offset distance L is consistent with the distance from the center line of the detection antenna installed in the Φ-axis antenna fixing device 9 or the θ-axis antenna fixing device 10 to the center line of the support column 7, thereby ensuring that when the support column 7 slides on the positive sliding horizontal axis 4 and the negative sliding horizontal axis 5, the phase center position of the detection antenna is always on the Y-axis.

[0039] like Figure 3 As shown, the negative sliding horizontal axis 5 and the positive sliding horizontal axis 4 are set at intervals to the left and right. The negative sliding horizontal axis 5 and the positive sliding horizontal axis 4 are symmetrical and mirror images of each other. The negative sliding vertical axis 3 and the positive sliding vertical axis 2 are set at intervals to the front and back. The length of the negative sliding vertical axis 3 is greater than the length of the positive sliding vertical axis 2.

[0040] The positive sliding vertical axis 2 corresponds to the positive direction of the X-axis. The range of the first length measurement scale 23 on the positive sliding vertical axis 2 is 130mm (located at the front end of the positive sliding vertical axis 2) to 350mm (located at the rear end of the positive sliding vertical axis 2). The negative sliding vertical axis 3 is marked with scales starting from position A. The range of the first length measurement scale 23 on the negative sliding vertical axis 3 is 0mm (located at the rear end of the negative sliding vertical axis 3) to -350mm (located at the front end of the negative sliding vertical axis 3). The positive sliding horizontal axis 4 corresponds to the positive direction of the Y-axis. The range of the second length measurement scale 24 on the positive sliding horizontal axis 4 is 30mm (located at the left end of the positive sliding horizontal axis 4) to 350mm (located at the right end of the positive sliding horizontal axis 4). The range of the second length measurement scale 24 on the negative sliding horizontal axis 5 is -30mm (located at the right end of the negative sliding horizontal axis 5) to -350mm (located at the left end of the negative sliding horizontal axis 5).

[0041] like Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, a base through hole 101 is provided inside the fixed base 1. The diameter of the base through hole 101 can be 30mm. During testing, the magnetic ring wire connected to the probe antenna passes through this hole. The axis of the base through hole 101 is parallel to the Z-axis. The axis of the base through hole 101 is perpendicular to and intersects the center line of the positive sliding vertical axis 2. The axis of the base through hole 101 is also perpendicular to and intersects the center line of the positive sliding horizontal axis 4. The diameter of the base through hole 101 is smaller than the distance between the positive sliding vertical axis 2 and the negative sliding vertical axis 3. The diameter of the base through hole 101 is also smaller than the distance between the positive sliding horizontal axis 4 and the negative sliding horizontal axis 5. The distances from the axis of the base through hole 101 to the positive sliding vertical axis 2, the negative sliding vertical axis 3, the positive sliding horizontal axis 4, and the negative sliding horizontal axis 5 are all the same.

[0042] The sliding base 6 has a roughly inverted U-shaped cross-section. A groove 601 is provided in the lower part of the sliding base 6. To prevent tipping, the groove 601 can have a T-shaped cross-section. The upper part of the positive sliding longitudinal axis 2, the upper part of the negative sliding longitudinal axis 3, the upper part of the positive sliding horizontal axis 4, or the upper part of the negative sliding horizontal axis 5 can be fitted into the groove 601 of the sliding base 6. The sliding base 6 can slide along the positive sliding longitudinal axis 2, the negative sliding longitudinal axis 3, the positive sliding horizontal axis 4, or the negative sliding horizontal axis 5. The length of the sliding base 6 is parallel to the extension direction of the groove 601. The length of the sliding base 6 is greater than the distance between the positive sliding longitudinal axis 2 and the negative sliding longitudinal axis 3, and also greater than the distance between the positive sliding horizontal axis 4 and the negative sliding horizontal axis 5. The width of the sliding base 6 is less than the distance between the positive sliding longitudinal axis 2 and the negative sliding longitudinal axis 3, and also less than the distance between the positive sliding horizontal axis 4 and the negative sliding horizontal axis 5.

[0043] The sliding base 6 can be made of existing transparent low-dielectric-constant materials. The length of the sliding base 6 can be 120mm, and the width can be 50mm. This size ensures that the sliding base 6 can directly span the gap between the negative sliding horizontal axis 5 and the positive sliding horizontal axis 4, as well as the gap between the negative sliding vertical axis 3 and the positive sliding vertical axis 2. When the sliding base 6 slides to the desired position, it can be connected and fixed to the positive sliding vertical axis 2, the negative sliding vertical axis 3, the positive sliding horizontal axis 4, or the negative sliding horizontal axis 5 using the first positioning screw 8 to achieve positioning.

[0044] The outer surface of the sliding base 6 is provided with a positioning mark line 602. The center line of the support column 7 and the positioning mark line 602 are located in the same vertical plane. The scale values ​​of the sliding base 6 on the first length measurement scale 23 and the second length measurement scale 24 can be viewed through the side of the sliding base 6. When the sliding base 6 is located on the positive sliding vertical axis 2 or the negative sliding vertical axis 3, the vertical plane is perpendicular to the X-axis, and the positioning mark line 602 can indicate the coordinate position of the support column 7 on the X-axis. When the sliding base 6 is located on the positive sliding horizontal axis 4 and the negative sliding horizontal axis 5, the vertical plane is perpendicular to the Y-axis, and the positioning mark line 602 can indicate the coordinate position of the support column 7 on the Y-axis. The current position is obtained by the offset of the positioning mark line 602 from the first length measurement scale 23 and the second length measurement scale 24.

[0045] The support column 7 is equipped with a third length measurement scale 25, the measurement direction of which is parallel to the Z-axis. The support column 7 and the sliding base 6 are connected vertically (e.g., glued) and fixed as a single unit. The Φ-axis antenna fixing device 9 or the θ-axis antenna fixing device 10 can be installed or removed from the support column 7 as needed. The support column 7 is an upright cylinder with a diameter of 28mm. On the outer circumference of the support column 7, at a distance of 150mm from the sliding base 6, there is a displacement third length measurement scale 25. The range of the third length measurement scale 25 is from -300mm (located at the lower end of the support column 7) to 300mm (located at the upper end of the support column 7).

[0046] like Figure 5 , Figure 6 , Figure 7 , Figure 8 As shown, the Φ-axis antenna fixing device 9 includes a first rotating bracket 11, a first connecting piece 12, and a fixing sleeve 13 connected in sequence. The connection direction of the first rotating bracket 11, the first connecting piece 12, and the fixing sleeve 13 is parallel to the plane containing the X-axis and Y-axis. The first rotating bracket 11 is fitted onto the outside of the support column 7. The Φ-axis antenna fixing device 9 can move up and down along the support column 7 or rotate around the support column 7 (360° rotation). The first rotating bracket 11 can be connected and fixed to the support column 7 by the second positioning screw 14. The fixing sleeve 13 contains an inner through hole 1301. The axis of the inner through hole 1301 is parallel to the center line of the support column 7. The distance between the axis of the inner through hole 1301 and the center line of the support column 7 is equal to the antenna set offset distance L (e.g., 100mm).

[0047] The Φ-axis antenna fixing device 9 also includes a plug-in support column 15, which has a cylindrical structure and is an upright cylindrical structure. The plug-in support column 15 includes an inner and outer first antenna mounting cavity 1501 and a support column sidewall 1502. The axis of the first antenna mounting cavity 1501 coincides with the axis of the inner through hole 1301. The outer circumferential surface of the support column sidewall 1502 includes a large-diameter section 1503 and a small-diameter section 1504 arranged vertically. The small-diameter section 1504 is matched and inserted into the inner through hole 1301. The outer diameter of the large-diameter section 1503 is larger than the diameter of the inner through hole 1301. The test antenna can be coaxially installed in the first antenna mounting cavity 1501. The test antenna can be connected and fixed to the plug-in support column 15 by a third positioning screw 16. That is, at this time, the axis of the test antenna coincides with the axis of the first antenna mounting cavity 1501, and the axis of the test antenna is parallel to the Z-axis. Multiple third positioning screws 16 are evenly spaced along the circumference of the insertion post 15, which can be adapted to install detection antenna families of different thicknesses. The inner diameter of the insertion post 15 is 20mm, and the inner diameter of the first rotating bracket 11 is 28mm.

[0048] like Figure 9 , Figure 10 , Figure 11 As shown, the θ-axis antenna fixing device 10 includes a second rotating bracket 17, a second connecting piece 18, and a fixing groove 19 connected in sequence. The connection direction of the second rotating bracket 17, the second connecting piece 18, and the fixing groove 19 is parallel to the plane containing the X-axis and Y-axis. The second rotating bracket 17 is fitted onto the support column 7. The θ-axis antenna fixing device 10 can move up and down along the support column 7 or rotate around the support column 7 (360° rotation). The second rotating bracket 17 can be connected and fixed to the support column 7 by a fourth positioning screw 20. An installation groove 1901 is provided in the upper surface of the fixing groove 19. The opening of the installation groove 1901 faces upward. The center line of the installation groove 1901 is perpendicular to the center line of the support column 7. The distance between the center line of the installation groove 1901 and the center line of the support column 7 is equal to the antenna set offset distance L (e.g., 100mm).

[0049] like Figure 9 , Figure 10 , Figure 11As shown, the θ-axis antenna fixing device 10 also includes a connector section 21. The connector section 21 has an inner and outer second antenna mounting cavity 2101 and a sidewall 2102. The outline of the cross-section of the mounting groove 1901 is an arc 1902. The lower part of the connector section 21 is fitted within the mounting groove 1901. The connector section 21 can slide along the centerline of the mounting groove 1901. The axis of the second antenna mounting cavity 2101 passes through the center of the circle containing the arc 1902. The axis of the second antenna mounting cavity 2101 and the centerline of the mounting groove 1901 are located in the same vertical plane, which is parallel to the Z-axis. The test antenna can be coaxially mounted within the second antenna mounting cavity 2101. The test antenna can be connected to the connector section 21 via a fifth positioning screw 22. That is, at this time, the axis of the test antenna coincides with the axis of the second antenna mounting cavity 2101, and the axis of the test antenna is parallel to the plane containing the X-axis and Y-axis. Multiple fifth positioning screws 22 are spaced apart circumferentially along the insertion pipe section 21, which can be adapted to install detection antenna families of different thicknesses. The inner diameter of the insertion pipe section 21 is 20 mm, and the inner diameter of the second rotating bracket 17 is 28 mm.

[0050] The following describes the working process of the ripple test fixture in the anechoic chamber during ripple testing, which includes Φ-axis ripple testing and θ-axis ripple testing.

[0051] In the Φ-axis ripple test, there are 10 test positions with specific coordinates (Y, Z) of (0, 0), (0, +150), (0, -150), (+150, 0), (+150, +150), (+150, -150), (0, +210), (+250, -150), (+250, 0), and (+250, +210), where the unit is mm. Taking (+250, +210) as an example... Figure 5 The Φ-axis antenna fixing device 9 is mounted on the support column 7, and the sliding base 6 is placed on the sliding horizontal axis (positive sliding horizontal axis 4 or negative sliding horizontal axis 5) of the fixed base 1, such as Figure 1As shown, first slide the sliding base 6 to the center of the two axes of the fixed base 1 (approximately located at the through hole 101 of the base). Then place the detection antenna in the first antenna mounting cavity 1501 of the Φ-axis antenna fixing device 9. Rotate the Φ-axis antenna fixing device 9 so that the straight line connecting the axis of the support column 7 and the axis of the detection antenna is perpendicular to the Y-axis. Then adjust the height of the Φ-axis antenna fixing device 9 so that the phase center position of the detection antenna is aligned with the +210mm position on the support column 7, that is, 210mm higher than the center position of the anechoic chamber. Finally, move the sliding base 6 to the positive sliding horizontal axis 4 until the positioning mark line 602 of the sliding base 6 coincides with the +250mm scale on the positive sliding horizontal axis 4. After the position is adjusted, tighten the positioning screws on the sliding base 6 and the plug-in support column 15. Replace the detection antennas of different frequency bands at each position, at least 9 antennas. When replacing the antennas, make fine adjustments according to the actual phase center.

[0052] In the θ-axis ripple test, there are 12 test positions with specific coordinates (X, Y, Z) of (0, 0, 0), (+150, 0, 0), (-150, 0, 0), (0, -150, 0), (0, +150, 0), (0, 0, +150), (0, 0, -150), (+250, 0, 0), (-250, 0, 0), (0, +250, 0), (0, -250, 0), (0, 0, +210), where the unit is mm. Since the θ-axis test points move in three dimensions, and except for (0, 0, 0), all other points have a positional offset along one of the three axes, if there is an offset along the X-axis, then... Figure 9 The θ-axis antenna fixing device 10 is placed on the sliding longitudinal axis (positive sliding longitudinal axis 2 or negative sliding longitudinal axis 3) of the fixed base 1, such as... Figure 2 As shown, if there is a Y-axis offset, place the device on the sliding horizontal axis (positive sliding horizontal axis 4 or negative sliding horizontal axis 5) of the fixed base 1. If there is a Z-axis offset, place the device at the center of the sliding horizontal axis of the fixed base 1 (between positive sliding horizontal axis 4 and negative sliding horizontal axis 5). Taking three positions as examples in sequence, (+150, 0, 0), (0, -150, 0), and (0, 0, +210), the first position is a +X axis offset of 150mm. First, install the θ-axis antenna fixing device 10 on the support column 7, place the sliding base 6 on the sliding vertical axis (positive sliding vertical axis 2 or negative sliding vertical axis 3), and then place the detection antenna horizontally. Figure 9The second antenna is installed in the cavity 2101 of the θ-axis antenna fixing device 10. The θ-axis antenna fixing device 10 is rotated to make the detection antenna parallel to the Y-axis. The detection antenna is adjusted so that its phase center coincides with the laser at the center of the anechoic chamber. Then, the sliding base 6 is moved along the +X direction so that the positioning mark line 602 of the sliding base 6 coincides with +250mm on the positive sliding vertical axis 2. That is, the phase center of the detection antenna is offset from the X-axis center by 150mm, completing the first position placement. The second position is offset by 150mm from the -Y axis. First, the sliding base 6 is placed on the sliding horizontal axis (positive sliding horizontal axis 4 or negative sliding horizontal axis 5). The θ-axis antenna fixing device 10 is rotated to make the detection antenna parallel to the Y-axis. The detection antenna is adjusted so that its phase center coincides with the laser at the center of the anechoic chamber. Then, the sliding base 6 is moved along the -Y direction so that the positioning mark line 602 of the sliding base 6 coincides with -150mm on the negative sliding horizontal axis 5. That is, the phase center of the detection antenna is offset from the X-axis center by 150mm, completing the second position placement. The third position is 210mm offset from the +Z axis. The sliding base 6 can be on any sliding vertical or horizontal axis, as long as the detection antenna is parallel to the Y axis. Adjust the sliding base 6 to ensure that the phase center of the antenna coincides with the laser at the center of the anechoic chamber. Then slide (move up and down) the θ axis antenna fixing device 10 towards the +Z axis until the phase center of the detection antenna is aligned with the +210mm mark on the support column 7, which is 210mm higher than the center of the anechoic chamber. This completes the placement of the third position.

[0053] The ripple test fixture for the anechoic chamber allows for six-directional movement of the probe antenna, enabling all ripple tests to be completed without the need for manual addition or removal of supports, thus improving testing efficiency and saving manpower and time costs. It also features a built-in displacement measurement scale for adjusting different positions during ripple testing, enabling precise control of the probe antenna position and improving the accuracy of the anechoic chamber system.

[0054] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, substitutions of equivalent components, or equivalent changes and modifications made within the scope of protection of the present invention, should still fall within the scope of the present invention. Furthermore, the technical features, technical solutions, and embodiments of the present invention can be freely combined and used.

Claims

1. A ripple testing fixture for a fully anechoic chamber, characterized in that, In a spatial rectangular coordinate system with X, Y, and Z axes as coordinate axes, the ripple test fixture for the anechoic chamber includes a fixed base (1), a support column (7), and an antenna fixing device. The upper surface of the fixed base (1) is provided with a positive sliding longitudinal axis (2), a negative sliding longitudinal axis (3), a positive sliding transverse axis (4), and a negative sliding transverse axis (5). The positive sliding longitudinal axis (2), negative sliding longitudinal axis (3), positive sliding transverse axis (4), and negative sliding transverse axis (5) are arranged in a cross shape. The center line of the positive sliding longitudinal axis (2) and the center line of the negative sliding longitudinal axis (3) coincide and are both parallel to the X-axis. The positive sliding transverse axis (4) The center line of the support column (7) coincides with the center line of the negative sliding horizontal axis (5) and is parallel to the Y axis. The center line of the support column (7) is parallel to the Z axis. The lower end of the support column (7) is provided with a sliding base (6). The support column (7) can move along the positive sliding vertical axis (2), the negative sliding vertical axis (3), the positive sliding horizontal axis (4) or the negative sliding horizontal axis (5) with the sliding base (6). The antenna fixing device is detachably connected to the support column (7). The antenna fixing device can move along the center line of the support column (7). The antenna fixing device is a Φ axis antenna fixing device (9) or a θ axis antenna fixing device (10).

2. The anechoic chamber ripple testing fixture according to claim 1, characterized in that, The fixed base (1) is a circular plate structure. The upper surface of the fixed base (1) is parallel to the plane where the X-axis and Y-axis are located. The positive sliding vertical axis (2) and the negative sliding vertical axis (3) are spaced apart along the X-axis. The positive sliding horizontal axis (4) and the negative sliding horizontal axis (5) are spaced apart along the Y-axis. The interval between the positive sliding vertical axis (2) and the negative sliding vertical axis (3) partially coincides with the interval between the positive sliding horizontal axis (4) and the negative sliding horizontal axis (5). The sliding base (6) can slide back and forth between the positive sliding vertical axis (2) and the negative sliding vertical axis (3). The sliding base (6) can also slide back and forth between the positive sliding horizontal axis (4) and the negative sliding horizontal axis (5).

3. The anechoic chamber ripple testing fixture according to claim 2, characterized in that, Both the positive sliding vertical axis (2) and the negative sliding vertical axis (3) are provided with a first length measurement scale (23). The measurement direction of the first length measurement scale (23) is parallel to the X-axis. The projection of the center line of the positive sliding vertical axis (2) onto the upper surface of the fixed base (1) passes through the center of the upper surface of the fixed base (1). Both the positive sliding horizontal axis (4) and the negative sliding horizontal axis (5) are provided with a second length measurement scale (24). The measurement direction of the second length measurement scale (24) is parallel to the Y-axis. The distance between the projection of the center line of the positive sliding horizontal axis (4) onto the upper surface of the fixed base (1) and the center of the upper surface of the fixed base (1) is equal to the antenna setting offset distance.

4. The anechoic chamber ripple testing fixture according to claim 2, characterized in that, The fixed base (1) is provided with a base through hole (101). The axis of the base through hole (101) is parallel to the Z-axis. The axis of the base through hole (101) is perpendicular to and intersects the center line of the positive sliding longitudinal axis (2). The axis of the base through hole (101) is also perpendicular to and intersects the center line of the positive sliding transverse axis (4). The diameter of the base through hole (101) is smaller than the distance between the positive sliding longitudinal axis (2) and the negative sliding longitudinal axis (3). The diameter of the base through hole (101) is also smaller than the distance between the positive sliding transverse axis (4) and the negative sliding transverse axis (5). The axis of the base through hole (101) is the same as the distance to the positive sliding longitudinal axis (2), the negative sliding longitudinal axis (3), the positive sliding transverse axis (4), and the negative sliding transverse axis (5).

5. The anechoic chamber ripple testing fixture according to claim 2, characterized in that, A sliding groove (601) is provided in the lower part of the sliding base (6). The cross-section of the sliding groove (601) is T-shaped. The upper part of the positive sliding longitudinal axis (2), the upper part of the negative sliding longitudinal axis (3), the upper part of the positive sliding horizontal axis (4) or the upper part of the negative sliding horizontal axis (5) are matched and inserted into the sliding groove (601) of the sliding base (6). The length direction of the sliding base (6) is parallel to the extension direction of the sliding groove (601). The length of the sliding base (6) is greater than the distance between the positive sliding longitudinal axis (2) and the negative sliding longitudinal axis (3). The length of the sliding base (6) is also greater than the distance between the positive sliding horizontal axis (4) and the negative sliding horizontal axis (5). The width of the sliding base (6) is less than the distance between the positive sliding longitudinal axis (2) and the negative sliding longitudinal axis (3). The width of the sliding base (6) is also less than the distance between the positive sliding horizontal axis (4) and the negative sliding horizontal axis (5).

6. The anechoic chamber ripple testing fixture according to claim 5, characterized in that, The support column (7) is provided with a third length measurement scale (25), the measurement direction of the third length measurement scale (25) is parallel to the Z axis, the outer surface of the sliding base (6) is provided with a positioning mark line (602), the center line of the support column (7) and the positioning mark line (602) are located in the same vertical plane; when the sliding base (6) is located on the positive sliding longitudinal axis (2) or the negative sliding longitudinal axis (3), the vertical plane is perpendicular to the X axis; when the sliding base (6) is located on the positive sliding horizontal axis (4) and the negative sliding horizontal axis (5), the vertical plane is perpendicular to the Y axis.

7. The anechoic chamber ripple testing fixture according to claim 3, characterized in that, The Φ-axis antenna fixing device (9) includes a first rotating bracket (11), a first connector (12), and a fixing sleeve (13) connected in sequence. The connection direction of the first rotating bracket (11), the first connector (12), and the fixing sleeve (13) is parallel to the plane containing the X-axis and the Y-axis. The first rotating bracket (11) is fitted onto the outside of the support column (7). The Φ-axis antenna fixing device (9) can move along the support column (7) or rotate around the support column (7). The first rotating bracket (11) can be connected and fixed to the support column (7) by the second positioning screw (14). The fixing sleeve (13) contains an inner through hole (1301). The axis of the inner through hole (1301) is parallel to the center line of the support column (7). The distance between the axis of the inner through hole (1301) and the center line of the support column (7) is equal to the antenna setting offset distance.

8. The anechoic chamber ripple testing fixture according to claim 7, characterized in that, The Φ-axis antenna fixing device (9) also includes a plug-in support column (15). The plug-in support column (15) is an upright cylindrical structure. The plug-in support column (15) includes an inner and outer first antenna mounting cavity (1501) and a support column sidewall (1502). The axis of the first antenna mounting cavity (1501) coincides with the axis of the inner through hole (1301). The outer circumferential surface of the support column sidewall (1502) includes a large-diameter section (1503) and a small-diameter section (1504) arranged vertically. The small-diameter section (1504) is matched and plugged into the inner through hole (1301). The test antenna can be coaxially installed in the first antenna mounting cavity (1501). The test antenna can be connected and fixed to the plug-in support column (15) by a third positioning screw (16).

9. The anechoic chamber ripple testing fixture according to claim 3, characterized in that, The θ-axis antenna fixing device (10) includes a second rotating bracket (17), a second connector (18), and a fixing groove (19) connected in sequence. The connection direction of the second rotating bracket (17), the second connector (18), and the fixing groove (19) is parallel to the plane containing the X-axis and the Y-axis. The second rotating bracket (17) is fitted onto the outside of the support column (7). The θ-axis antenna fixing device (10) can move along the support column (7) or rotate around the support column (7). The second rotating bracket (17) can be connected and fixed to the support column (7) by the fourth positioning screw (20). An installation groove (1901) is provided in the upper surface of the fixing groove (19). The opening of the installation groove (1901) faces upward. The center line of the installation groove (1901) is perpendicular to the center line of the support column (7). The distance between the center line of the installation groove (1901) and the center line of the support column (7) is equal to the antenna setting offset distance.

10. The anechoic chamber ripple testing fixture according to claim 9, characterized in that, The θ-axis antenna fixing device (10) also includes a plug-in section (21), which includes an inner and outer second antenna mounting cavity (2101) and a tube sidewall (2102). The outline of the cross-section of the mounting groove (1901) is an arc (1902). The lower part of the plug-in section (21) is matched and set in the mounting groove (1901). The axis of the second antenna mounting cavity (2101) passes through the center of the circle where the arc (1902) is located. The axis of the second antenna mounting cavity (2101) and the center line of the mounting groove (1901) are located in the same vertical plane. The test antenna can be coaxially installed in the second antenna mounting cavity (2101). The test antenna can be connected and fixed to the plug-in section (21) by the fifth positioning screw (22).

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