Totally-closed curved surface electromagnetic parameter testing device based on fitting algorithm

Abstract

The utility model discloses a totally-enclosed curved surface electromagnetic parameter testing device based on a fitting algorithm. Comprising a linear sliding rail mechanism arranged on the ground of a measuring chamber, a fixed supporting column installed on the linear sliding rail mechanism, a linear driving device for driving the fixed supporting column to slide, a lifting column installed on the fixed supporting column and a lifting driving device for driving the lifting column to move up and down. The device comprises a lifting column, a semi-annular probe mounting frame which is rotatably mounted on the lifting column around a horizontal rotating shaft, a rotation driving device for driving the probe mounting frame to rotate, a receiving and transmitting probe mounted on the probe mounting frame, and an antenna positioning device for positioning an antenna at the circle center position of the probe mounting frame, according to the utility model, the operation is stable, the multi-probe test with relatively high flexibility can be realized, the complete closed scanning test can be formed, the condition of data missing in a truncation area is avoided, and the completeness and reliability of a test result are improved.

Description

Technical Field

[0001] This utility model relates to an antenna testing system, and more particularly to a fully enclosed curved surface electromagnetic parameter testing device based on a fitting algorithm. Background Technology

[0002] Antennas are a crucial component of wireless communication systems. As an energy converter, their primary function is to transmit or receive radio wave signals. In transmit mode, the antenna converts high-frequency electromagnetic energy in the transmission line into electromagnetic waves in free space; in receive mode, the antenna converts electromagnetic waves in free space into high-frequency electromagnetic signals within the transmission line. The electromagnetic radiation parameters of an antenna determine the signal propagation efficiency and the quality of wireless communication, while the scattering parameters reflect the reflection, refraction, and diffraction behavior of electromagnetic waves on the antenna surface and in the surrounding environment, serving as important criteria for evaluating antenna performance and electromagnetic compatibility.

[0003] Existing electromagnetic radiation parameter testing systems can be broadly categorized into three types: near-field testing systems, far-field testing systems, and compacted-field testing systems. Among these, cylindrical near-field systems are commonly used to test medium- and high-gain antennas. However, cylindrical near-field systems can only acquire data from the curved surface of the cylinder, failing to cover the end face, resulting in a data gap. Therefore, developing improved testing methods to acquire data from the cylinder's end face, resolving the truncated area problem, and achieving complete data acquisition is crucial.

[0004] Traditional electromagnetic scattering parameter measurement systems are typically far-field 2D monostation RCS tests, which have significant limitations. Utility Model Content

[0005] To overcome the above shortcomings, this invention provides a fully enclosed curved surface electromagnetic parameter testing device based on a fitting algorithm. This device can effectively solve the cutoff region problem in near-field testing of antenna cylinders while ensuring the reliability and stability of the testing process. It can also realize single-station, bi-station, multi-station, and imaging tests of electromagnetic scattering parameters.

[0006] The technical solution adopted by this utility model to solve its technical problem is: a fully enclosed surface electromagnetic parameter testing device based on a fitting algorithm, including a linear slide rail mechanism, fixed support columns, a linear drive device, lifting columns, a lifting drive device, a transceiver probe, a probe mounting bracket, a rotary drive device, an antenna positioning device, a testing system, and a controller. Two linear slide rail mechanisms are fixedly installed parallel to each other on the floor of the measuring chamber. Two sets of fixed support columns are fixedly installed on the sliders of the linear slide rail mechanisms. The linear drive device drives the two sets of fixed support columns to slide synchronously linearly on the linear slide rails of the linear slide rail mechanisms. Two lifting columns are respectively installed on the two sets of fixed support columns, capable of vertical movement. The lifting drive device drives the lifting columns to move up and down to a specified height. The two ends of the semi-circular probe mounting bracket are respectively mounted on the lifting columns, capable of rotating around a horizontally extending pivot. The rotary drive device drives the probe mounting bracket. The system rotates 360 degrees around a horizontally extending axis. Several transceiver probes are fixedly mounted at intervals on a probe mounting frame, with all probes facing the center of the frame. The antenna under test (TUT) can be fixedly mounted on an antenna positioning device via connectors. The antenna positioning device positions the TUT at the center of the mounting frame. The transceiver probes can transmit electromagnetic wave signals to the TUT located at the center of the mounting frame, or receive electromagnetic wave signals radiated to the probe location. Both the transceiver probes and the TUT are connected to the test system via wired or wireless communication. The test system analyzes the received signals to perform electromagnetic parameter measurements (including electromagnetic radiation parameters, scattering parameters, and imaging tests) on the TUT. The test system is connected to a controller via electrical signals, which controls the linear drive device, lifting drive device, rotation drive device, and probe operation.

[0007] As a further improvement of this utility model, a test wall is also provided. The test wall extends vertically and is perpendicular to the linear slide rail mechanism. A linear probe array is provided on the test wall. The linear probe array is positioned opposite the antenna under test on the antenna positioning device. The linear probe array can work in conjunction with the transceiver probe on the probe mounting ring to support multi-station measurement of electromagnetic scattering parameters.

[0008] As a further improvement of this utility model, the probe mounting bracket is a semi-circular ring, semi-elliptical ring or semi-polygonal ring with a central angle of not less than 180 degrees.

[0009] As a further improvement of this utility model, the probe mounting bracket includes a semi-circular mounting plate and several support rods. The two semi-circular mounting plates are arranged parallel to each other along the semi-circular axis. The two ends of the several support rods are fixedly connected to the opposite sidewalls of the two semi-circular mounting plates, so that several hollow probe receiving spaces are formed between the two semi-circular mounting plates. Each transceiver probe is fixedly installed in the corresponding probe receiving space.

[0010] As a further improvement of this utility model, the semi-annular mounting plate is made of aluminum.

[0011] As a further improvement of this utility model, the semi-circular mounting plate is provided with a number of probe mounting holes at even intervals, and the number of transceiver probes are installed on different probe mounting holes to realize the adjustment of the probe spacing.

[0012] As a further improvement of this utility model, the fixed support column, the lifting column and the probe mounting frame are all wrapped with a layer of absorbing material. The absorbing material layer on the outside of the probe mounting frame is provided with a clearance hole that is directly opposite to each transceiver probe. The transceiver probe can extend out of the absorbing material layer through the clearance hole to transmit and receive signals.

[0013] As a further improvement of this utility model, the antenna positioning device includes a support rod and a suspension rope. The support rod can be fixedly installed on the floor of the measuring room between two linear slide rail mechanisms. The antenna under test is fixedly installed on the upper end of the support rod through a connector. The upper end of the suspension rope can be fixedly installed on the ceiling of the measuring room, and the antenna under test is fixedly installed on the lower end of the suspension rope through a connector.

[0014] As a further improvement of this utility model, the ground is also provided with a pole sliding track and a pole sliding drive device. The pole is fixedly installed on the slider of the pole sliding track. The pole sliding drive device drives the pole to slide along the pole sliding track, thereby making the antenna under test on the pole located at the center position of the probe mounting bracket for testing, or making the pole leave the movement area of ​​the probe mounting bracket to avoid obstacles.

[0015] The ceiling is also equipped with a suspension rope sliding track and a suspension rope sliding drive device. The upper end of the suspension rope is fixedly installed on the slider of the suspension rope sliding track. The suspension rope sliding drive device drives the upper end of the suspension rope to slide along the suspension rope sliding track, so that the antenna under test at the lower end of the suspension rope is located at the center position of the probe mounting bracket for testing, or causes the suspension rope to leave the movement area of ​​the probe mounting bracket to avoid obstacles.

[0016] As a further improvement of this utility model, the rotary drive device includes a connecting flange, a rotary driver, a servo motor, and a counterweight device. The two connecting flanges are respectively fixedly installed on the outer side walls of both ends of the semi-annular probe mounting frame. The rotary driver is installed on the connecting flange. The servo motor is fixedly installed on the upper end of the lifting column. The power output shaft of the servo motor is connected to the rotary shaft of the rotary driver. The rotary shaft of the rotary driver forms a horizontally extending shaft. The counterweight device is fixedly installed at the end of the probe mounting frame. The counterweight device is used to balance the weight of the probe mounting frame on both sides of the horizontally extending shaft.

[0017] The beneficial technical effects of this utility model are as follows: This utility model uses a layered design to splice two semi-circular mounting plates with a central angle greater than 180 degrees to form a semi-circular frame structure. This allows for the installation of any number of transceiver probes at arbitrary intervals inside the probe mounting frame, enabling highly flexible multi-probe testing. The probe mounting frame of this utility model can reduce its weight and improve its rotational stability while ensuring structural strength. This utility model also uses a rotation drive device to drive the probe mounting frame to rotate 360 ​​degrees around the outside of the antenna under test, and uses a linear slide rail mechanism to control the distance between the transceiver probe and the antenna under test. The antenna position is fixed by using an antenna positioning device consisting of a support rod and a suspension rope. This allows the probe mounting frame to sequentially perform near-field testing of the left end face, right end face, and cylindrical surface of the cylinder based on rotation, thereby obtaining complete test data. When the probe mounting bracket is rotated to a vertical position with the semi-circle facing up or down, and in conjunction with the horizontal movement of the linear slide rail mechanism, the probe can acquire scan test data at the curved surface of the near-field cylinder on the outer side of the antenna under test. When the probe mounting bracket is rotated to a horizontal position and selectively combined with its rotation, the probe acquires hemispherical scan test data at the end face of the near-field cylinder on the outer side of the antenna under test. The left and right hemispherical scans together with the cylindrical curved surface scan form a complete closed scan test, avoiding the loss of data in the truncated area and improving the completeness and reliability of the test results. Attached Figure Description

[0018] Figure 1 This is a diagram showing the state of the probe mounting bracket of this utility model when it rotates past the antenna under test.

[0019] Figure 2 This is a diagram showing the probe mounting bracket of this utility model in a horizontal position.

[0020] Figure 3 This is a schematic diagram of the lifting drive device and the rotating drive device of this utility model.

[0021] Figure 4 This is a schematic diagram of the scanning field formed by this utility model. Detailed Implementation

[0022] Example: A fully enclosed surface electromagnetic parameter testing device based on a fitting algorithm includes a linear slide rail mechanism 1, fixed support columns 2, a linear drive device 18, lifting columns 3, a lifting drive device 4, a transceiver probe 5, a probe mounting bracket 6, a rotation drive device 7, an antenna positioning device, a testing system, and a controller. Two linear slide rail mechanisms 1 are fixedly installed parallel to each other on the floor 8 of the measuring chamber. Two sets of fixed support columns 2 are fixedly installed on the sliders of the linear slide rail mechanism 1. The linear drive device 18 drives the two sets of fixed support columns 2 to slide synchronously linearly on the linear slide rails of the linear slide rail mechanism 1. Two lifting columns 3 are respectively installed on the two sets of fixed support columns 2, capable of vertical movement. The lifting drive device 4 drives the lifting columns 3 to move up and down to a specified height. The semi-circular probe mounting bracket 6 is mounted on the lifting column 3 at both ends, capable of rotating around a horizontally extending shaft. The rotation drive device 7 drives the probe mounting bracket 6 to rotate around a horizontally extending shaft. The extended shaft rotates 360 degrees, and several transceiver probes 5 are fixedly installed at intervals on the probe mounting frame 6, with all transceiver probes 5 facing the center of the probe mounting frame 6. The antenna under test can be fixedly installed on the antenna positioning device through connectors, and the antenna positioning device can position the antenna under test at the center of the probe mounting frame 6. The transceiver probes 5 can transmit electromagnetic wave signals to the antenna under test located at the center of the probe mounting frame 6, or receive electromagnetic wave signals radiated to the probe position. The transceiver probes 5 and the antenna under test can communicate with the test system via wired or wireless communication. The test system performs data analysis based on the received signals to realize the electromagnetic parameter measurement of the linear under test (including electromagnetic radiation parameters, scattering parameters, and imaging tests). The test system is connected to the controller via electrical signals, and the controller can control the linear drive device 18, the lifting drive device 4, the rotation drive device 7, and the probe operation.

[0023] The testing system includes a computer, an RF amplifier, and a display unit. The computer is used to receive and process information, the RF amplifier is used to process the transmit and receive signals, the display unit is used to display the test results intuitively, and the controller is used to send control signals for probe switching, probe mounting bracket 6 rotation, and fixed support column 2 movement.

[0024] Before testing, the two sets of fixed support columns 2 are driven by the linear drive device 18 to move on the two linear slide rail mechanisms 1, so as to make sliding adjustments and precise positioning at any position, thereby flexibly controlling the center distance between the transceiver probe 5 and the antenna under test.

[0025] During testing, when the probe mounting bracket 6 is in a vertical position, the transceiver probe 5 can acquire scan test data at the curved surface of the near-field cylinder on the outer side of the antenna under test. When the probe mounting bracket 6 rotates past the antenna under test, the transceiver probe 5 acquires hemispherical scan test data at the end face of the near-field cylinder on the outer side of the antenna under test. The upper and lower hemispherical scans together with the cylindrical curved surface scan form a complete closed scan test, avoiding the loss of data in the truncated area and improving the completeness and reliability of the test results.

[0026] A test wall 9 is also provided, which extends vertically and is perpendicular to the linear slide rail mechanism 1. A linear probe array 10 is provided on the test wall 9, which is positioned opposite to the antenna under test on the antenna positioning device. The linear probe array 10 can work in conjunction with the transceiver probe 5 on the probe mounting bracket 6 ring to support multi-station measurement of electromagnetic scattering parameters.

[0027] The probe mounting bracket 6 is a semi-circular ring, semi-elliptical ring, or semi-polygonal ring with a central angle of not less than 180 degrees. The central angle of the probe mounting bracket 6 is not less than 180 degrees, which allows the probe mounting bracket 6 to completely cover the near-field column radiation area of ​​the antenna under test when rotating, thereby enabling the transceiver probe 5 to obtain complete closed-loop scanning data.

[0028] The probe mounting frame 6 includes a semi-annular mounting plate 61 and several support rods 62. Two semi-annular mounting plates 61 are arranged parallel to each other along the axial direction of the semi-annular shape. The two ends of the support rods 62 are fixedly connected to the opposite sidewalls of the two semi-annular mounting plates 61, forming several hollow probe receiving spaces between the two semi-annular mounting plates 61. Each transceiver probe 5 is fixedly installed within one of these probe receiving spaces. The two semi-annular mounting plates 61 are supported and fixed by the support rods 62, forming a semi-annular frame structure. The support rods 62 maintain the stability of the entire semi-annular frame structure. This design effectively reduces the weight of the probe mounting frame 6 and facilitates its rotational testing. To further reduce the weight of the probe mounting frame 6, the semi-annular mounting plates 61 are preferably provided with several hollowed-out holes. The mounting ends of each transceiver probe 5 are fixedly installed on the opposite sidewalls of the two semi-annular mounting plates 61 to achieve fixed positioning.

[0029] The semi-annular mounting plate 61 is made of aluminum. This material can further reduce its weight while ensuring its structural strength and resistance to deformation.

[0030] The semi-circular mounting plate 61 has a plurality of probe mounting holes evenly spaced, and several transceiver probes 5 are installed in different probe mounting holes to adjust the probe spacing. The probe mounting bracket 6 forms a hollow structure, allowing multiple sets of transceiver probes 5 to be precisely installed at any position within it. The installation path of the transceiver probes 5 is also consistent with the semi-circular mounting plate 61, and the transceiver probes 5 are distributed in an arc array, with the distance between the transceiver probes 5 adjustable during installation. This design greatly improves the freedom of installation, and the arrangement of multiple sets of transceiver probes 5 can form multiple test channels and realize multi-probe testing. Compared with single-probe testing, this testing method greatly improves testing efficiency and testing range, and ensures testing accuracy.

[0031] The fixed support column 2, the lifting column 3, and the probe mounting bracket 6 are all covered with a layer of absorbing material 11. The absorbing material layer 11 on the outside of the probe mounting bracket 6 has recessed holes that correspond to the various transceiver probes 5, allowing the transceiver probes 5 to extend through these holes to the outside of the absorbing material layer 11 for signal transmission and reception. This design absorbs electromagnetic wave signals radiated to the fixed support column 2, the lifting column 3, and the probe mounting bracket 6, preventing scattering of electromagnetic wave signals by the metal material and enhancing the accuracy of the test data.

[0032] The antenna positioning device includes a support rod 12 and a suspension rope 13. The support rod 12 can be fixedly installed on the floor 8 of the measuring chamber between two linear slide rail mechanisms 1. The antenna under test is fixedly installed on the upper end of the support rod 12 through a connector. The upper end of the suspension rope 13 can be fixedly installed on the ceiling 17 of the measuring chamber, and the antenna under test is fixedly installed on the lower end of the suspension rope 13 through a connector. When the probe mounting frame 6 needs to perform a moving test above the antenna under test, the antenna under test is placed on the support rod 12; when the probe mounting frame 6 needs to perform a moving test below the antenna under test, the antenna under test is suspended on the suspension rope 13.

[0033] The ground 8 is also provided with a pole sliding track 14 and a pole sliding drive device 15. The pole 12 is fixedly installed on the slider of the pole sliding track 14. The pole sliding drive device 15 drives the pole 12 to slide along the pole sliding track 14, so that the antenna under test on the pole 12 is located at the center position of the probe mounting bracket 6 for testing, or so that the pole 12 is removed from the movement area of ​​the probe mounting bracket to avoid obstacles.

[0034] The ceiling is also equipped with a suspension rope sliding track 16 and a suspension rope sliding drive device. The upper end of the suspension rope 13 is fixedly installed on the slider of the suspension rope sliding track 16. The suspension rope sliding drive device drives the upper end of the suspension rope 13 to slide along the suspension rope sliding track 16, thereby making the antenna under test at the lower end of the suspension rope 13 located at the center position of the probe mounting bracket 6 for testing, or making the suspension rope 13 leave the movement area of ​​the probe mounting bracket to avoid obstacles.

[0035] By moving the support pole 12 and suspension rope 13 away from the movement area of ​​the probe mounting bracket 6, interference from the rotation of the probe mounting bracket 6 during testing is avoided, ensuring the reliability and stability of the measurement. Furthermore, the support pole 12 and suspension rope 13 can also be disassembled for this purpose, or the support pole 12 can be raised or folded, and the suspension rope 13 can be pulled out and concealed for storage.

[0036] The rotary drive device 7 includes connecting flanges 63, a rotary driver 64, a servo motor 65, and a counterweight device. The two connecting flanges 63 are respectively fixedly installed on the outer walls of both ends of the semi-annular probe mounting frame 6. The rotary driver 64 is mounted on the connecting flanges 63. The servo motor 65 is fixedly installed on the upper end of the lifting column 3. The power output shaft of the servo motor 65 is connected to the rotary shaft of the rotary driver 64, forming a horizontally extending shaft. The counterweight device is fixedly installed at the end of the probe mounting frame 6. The counterweight device is used to balance the weight of the probe mounting frame 6 on both sides of the horizontally extending shaft. The counterweight device reduces the possibility of rotational instability caused by the shaft being subjected to only one-sided force, ensuring the stress stability of the shaft and thus improving the rotational reliability of the probe mounting frame 6.

[0037] The implementation principle of this embodiment is as follows: During testing, the operator fixes the antenna under test onto the antenna positioning device, and the fixed support column 2 slides along the linear slide rail mechanism 1 to a suitable testing position. The rotation drive device 7 drives the probe mounting bracket 6 to rotate outside the antenna under test. When performing a curved surface scan of the cylindrical near field, the probe mounting bracket 6 is rotated to a vertical state with the semi-circle facing up or down (e.g., ...). Figure 1 As shown), the horizontal movement of the linear guide mechanism 1 can be completed using the existing cylindrical near-field testing method; when performing the left end face test of the cylindrical near-field, the antenna fixing position is changed, and the test frame is adjusted to the desired position. Figure 2 As shown, and selectively combined with the rotation of probe mounting bracket 6, a specified elevation angle scan or full-angle scan is performed; when performing a test on the right end face of the cylindrical near field, the antenna fixing position is changed again, and the test bracket is adjusted to be in sync with the target. Figure 2In the opposite positional state, selectively combined with the rotation of probe mount 6, a specified elevation angle scan or full-angle scan is performed. After collecting complete test data, the test data is transmitted to the test system to obtain the near-field amplitude and phase data of the antenna under test. Finally, through rigorous mathematical calculations, the near-field data is converted into far-field data, enabling an accurate and reliable evaluation of the performance indicators of the antenna under test.

Claims

1. A full-enclosed curved surface electromagnetic parameter testing device based on a fitting algorithm, characterized by: The system includes a linear slide rail mechanism (1), fixed support columns (2), a linear drive device (18), lifting columns (3), lifting drive device (4), transceiver probes (5), probe mounting brackets (6), a rotary drive device (7), an antenna positioning device, a testing system, and a controller. Two linear slide rail mechanisms are fixedly installed parallel to each other on the floor (8) of the measuring room. Two sets of fixed support columns are fixedly installed on the sliders of the linear slide rail mechanism. The linear drive device drives the two sets of fixed support columns to slide synchronously on the linear slide rail of the linear slide rail mechanism. Two lifting columns are respectively installed on the two sets of fixed support columns. On the support column, the lifting drive device drives the lifting column to move up and down to a specified height. The two ends of the semi-circular probe mounting bracket are respectively mounted on the lifting column, which can rotate around the horizontally extending shaft. The rotation drive device drives the probe mounting bracket to rotate 360 ​​degrees around the horizontally extending shaft. Several transceiver probes are fixedly mounted on the probe mounting bracket at intervals, and all transceiver probes face the center of the probe mounting bracket. The antenna under test can be fixedly mounted on the antenna positioning device through the connector. The antenna positioning device can make the antenna under test located at the center of the probe mounting bracket. The antenna positioning device includes a support rod (12) and The suspension rope (13) and the support rod can be fixedly installed on the floor of the measuring room between two linear slide rail mechanisms. The antenna under test is fixedly installed on the upper end of the support rod through a connector. The upper end of the suspension rope can be fixedly installed on the ceiling (17) of the measuring room. The antenna under test is fixedly installed on the lower end of the suspension rope through a connector. The transceiver probe can transmit electromagnetic wave signals to the antenna under test located at the center of the probe mounting frame, or receive electromagnetic wave signals radiated to the probe position. Both the transceiver probe and the antenna under test communicate with the testing system via wired or wireless communication. The testing system performs data analysis based on the received signals to achieve [the desired result]. Electromagnetic parameters are measured on the linear antenna under test. The test system is connected to the controller via electrical signals. The controller can control the linear drive device, lifting drive device, rotation drive device and probe operation. The rotation drive device drives the probe mounting frame to rotate 360 ​​degrees around the outside of the antenna under test. The distance between the transceiver probe and the antenna under test is controlled by the linear slide rail mechanism. The antenna position is fixed by the antenna positioning device consisting of a support rod and a suspension rope. The probe mounting frame can perform tests on the left end face, right end face and cylindrical surface of the cylinder in the near field in a rotational manner, thereby obtaining complete test data.

2. The fully enclosed curved surface electromagnetic parameter testing device based on fitting algorithm according to claim 1 is characterized in that: a test wall (9) is also provided, the test wall extends in the vertical direction and is perpendicular to the linear slide rail mechanism, a linear probe array (10) is provided on the test wall, the linear probe array is set opposite to the antenna under test on the antenna positioning device, and the linear probe array can work in coordination with the transceiver probe on the probe mounting ring, thereby supporting multi-station measurement of electromagnetic scattering parameters.

3. The closed-form surface electromagnetic parameter testing device based on fitting algorithm according to claim 1, characterized in that: The probe mounting bracket is a semi-circular ring, semi-elliptical ring, or semi-polygonal ring with a central angle of not less than 180 degrees.

4. The full enclosed curved surface electromagnetic parameter testing device based on fitting algorithm according to claim 1 or 3, characterized in that: The probe mounting bracket includes a semi-circular mounting plate (61) and several support rods (62). The two semi-circular mounting plates are arranged parallel to each other along the semi-circular axis. The two ends of the several support rods are fixedly connected to the opposite side walls of the two semi-circular mounting plates, so that several hollow probe receiving spaces are formed between the two semi-circular mounting plates. Each transceiver probe is fixedly installed in the probe receiving space.

5. The closed-form surface electromagnetic parameter testing device based on fitting algorithm according to claim 4, characterized in that: The semi-annular mounting plate is made of aluminum.

6. The fully enclosed curved surface electromagnetic parameter testing device based on fitting algorithm according to claim 4, characterized in that: a plurality of probe mounting holes are evenly spaced on the semi-annular mounting plate, and a plurality of transceiver probes are mounted on different probe mounting holes to realize the adjustment of the probe spacing.

7. The fitted algorithm based closed surface electromagnetic parameter testing device according to claim 1, characterized in that: The fixed support column, the lifting column and the probe mounting frame are all wrapped with a layer of absorbing material (11). The absorbing material layer on the outside of the probe mounting frame has a clearance hole that is directly opposite to each transceiver probe. The transceiver probe can extend out of the absorbing material layer through the clearance hole to transmit and receive signals.

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