A multi-antenna multi-functional anechoic chamber and system for electromagnetic compatibility testing

Abstract

The present specification relates to a multi-antenna multi-function anechoic chamber and system for electromagnetic compatibility test, the anechoic chamber comprising: a shielded room, the inner wall and top wall of which are provided with wave-absorbing materials; a turntable arranged at the center of the ground in the shielded room; the ground in the shielded room comprises a wave-absorbing ground and a reflecting ground; in the shielded room, a plurality of antennas are arranged around the center of the turntable, at least one of the plurality of antennas is arranged above the reflecting ground to perform radiation disturbance measurement; at least one of the plurality of antennas is arranged above the wave-absorbing ground to perform radiation spurious test or radiation immunity test. The technical effect of realizing an anechoic chamber to complete multiple electromagnetic compatibility tests, improve test efficiency and reduce comprehensive cost is achieved.

Description

Technical Field

[0001] This specification relates to the field of electromagnetic testing technology, and in particular to a multi-antenna, multi-functional anechoic chamber and system for electromagnetic compatibility testing. Background Technology

[0002] In addition to using appropriate instruments and testing systems, electromagnetic compatibility testing of communication equipment also requires appropriate testing venues, such as anechoic chambers.

[0003] Radiated disturbance measurement, radiated spurious emission measurement, and radiated immunity test are all essential test items for electromagnetic compatibility testing of communication equipment. There are differences in the anechoic chamber used for radiated disturbance measurement, radiated spurious emission measurement, and radiated immunity test, as well as the test setup, antenna, and test table used.

[0004] Currently, single-room anechoic chambers have limited functionality and cannot be used for radiated disturbance measurement, radiated stray emission measurement, and radiated immunity testing. Using multiple anechoic chambers for measurements results in high construction costs, large space requirements, and the need for multiple testing systems, leading to overall high costs. Summary of the Invention

[0005] To address the technical problems of existing traditional electromagnetic compatibility (EMC) testing anechoic chambers for communication equipment, such as limited functionality, low testing efficiency, high construction costs, and inflexible use, a novel multi-antenna, multi-functional EMC testing anechoic chamber for communication equipment is provided. This chamber enables multiple EMC tests to be performed in a single anechoic chamber, improving testing efficiency and reducing overall costs.

[0006] In some embodiments of this specification, a multi-antenna, multi-functional anechoic chamber for electromagnetic compatibility testing is disclosed, comprising: The shielded room has wave-absorbing materials installed on its inner walls and top walls; A turntable is located in the central area of ​​the floor inside the shielded room. The floor inside the shielding room includes both absorbing and reflective surfaces. Inside the shielded room, multiple antennas are arranged around the center of the turntable. At least one of the multiple antennas is positioned above the reflecting ground to perform radiated disturbance measurements; at least one of the multiple antennas is positioned above the absorbing ground to perform radiated spurious emissions tests or radiated immunity tests.

[0007] Furthermore, the maximum radiation direction of the main beam of each of the multiple antennas is aligned with the center of the turntable, and the multiple antennas have different azimuth angles relative to the center of the turntable on the horizontal plane.

[0008] Furthermore, the multiple antennas include: At least one receiving antenna is provided for receiving electromagnetic signals from the device under test on the turntable in order to perform radiated interference testing or radiated spurious emissions testing. At least one transmitting antenna is used to radiate an electromagnetic field to the device under test on the turntable in order to perform a radiated immunity test.

[0009] Furthermore, the receiving antenna includes: A first intermediate frequency receiving antenna and a first low frequency receiving antenna are disposed above the reflective ground; The first intermediate frequency receiving antenna, which is set on the reflective ground, is used to receive electromagnetic signals in the first intermediate frequency band emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform radiated interference test in the first intermediate frequency band. A first low-frequency receiving antenna is installed on the reflective ground to receive electromagnetic signals in the first low-frequency band emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform radiated interference tests in the first low-frequency band.

[0010] Furthermore, the receiving antenna includes a composite antenna disposed above the absorbing ground surface; The composite antenna is used to receive a first high-frequency electromagnetic signal emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform radiated interference testing in the first high-frequency band. Alternatively, it can be used to receive a second high-frequency electromagnetic signal emitted from the device under test on the turntable when it is in signal transmission state, in order to perform a second high-frequency band radiated spurious emission test.

[0011] Furthermore, the receiving antenna includes: A second intermediate frequency receiving antenna and a second low frequency receiving antenna are disposed above the absorbing ground. The second intermediate frequency receiving antenna is used to receive the second intermediate frequency electromagnetic signal emitted by the device under test on the turntable when it is in the signal transmission state, so as to perform radiated spurious emissions testing in the second intermediate frequency band. The second low-frequency receiving antenna is used to receive the second low-frequency electromagnetic signal emitted by the device under test on the turntable when it is in signal transmission state, so as to perform radiated spurious emissions testing in the second low-frequency band.

[0012] Furthermore, the electromagnetic wave propagation path between at least one antenna positioned above the reflective ground and the turntable includes a reflection path provided by the reflective ground; The environment in which the electromagnetic wave propagation path between at least one antenna positioned above the absorbing ground and the turntable is located is composed of the absorbing ground and wall absorbing materials to absorb reflected waves.

[0013] In some embodiments of this specification, an electromagnetic compatibility testing system is provided, comprising: An anechoic chamber and multiple testing instrument systems; The anechoic chamber includes: a shielded room, the inner walls and top walls of which are provided with wave-absorbing material; a turntable, located in the central area of ​​the floor inside the shielded room; the floor inside the shielded room includes wave-absorbing floor and reflective floor. Multiple antennas are arranged around the center of the turntable inside the shielded room; The multiple test instrument systems include at least one radiated disturbance measurement system, at least one radiated stray emission measurement system, and at least one radiated immunity test system. At least one antenna deployed above the reflective ground is connected to the radiated disturbance measurement system, and at least one antenna deployed above the absorbing ground is connected to the radiated spurious emissions measurement system or the radiated immunity test system.

[0014] Furthermore, the multiple antennas include: At least one receiving antenna is provided for receiving electromagnetic signals from the device under test on the turntable in order to perform radiated interference testing or radiated spurious emissions testing. At least one transmitting antenna is used to radiate an electromagnetic field to the device under test on the turntable in order to perform a radiated immunity test.

[0015] The multi-antenna, multi-functional anechoic chamber for electromagnetic compatibility testing provided in this manual features an electromagnetic wave propagation path between at least one antenna positioned above a reflecting surface and a turntable, including a reflection path provided by the reflecting surface. This configuration is suitable for radiated disturbance measurements that utilize the ground reflection effect and can simulate a real electromagnetic environment. Alternatively, the electromagnetic wave propagation path between at least one antenna positioned above an absorbing surface and a turntable is situated in an environment composed of absorbing surface and wall absorbing materials. This environment effectively absorbs reflected waves, creating near-free-space test conditions suitable for radiated spurious emissions testing and radiated immunity testing.

[0016] With this design, the anechoic chamber can perform a variety of different electromagnetic compatibility tests in the same space, including radiated disturbance tests, radiated spurious tests, and radiated immunity tests, which greatly improves testing efficiency and equipment utilization, while ensuring the accuracy and reliability of test results. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments or prior art of this specification, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A schematic diagram of a multi-antenna, multi-functional anechoic chamber for electromagnetic compatibility testing provided in the embodiments of this specification; Figure 2 This is another schematic diagram of a multi-antenna, multi-functional anechoic chamber for electromagnetic compatibility testing provided in the embodiments of this specification. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this specification, and not all embodiments. Based on the embodiments in this specification, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this specification.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0021] This specification provides the operational steps of the methods described in the embodiments or flowcharts, but based on conventional or non-inventive labor, more or fewer operational steps may be included. The order of steps listed in the embodiments is merely one possible execution order among many and does not represent the only possible execution order. In actual system or device products, the methods shown in the embodiments or drawings can be executed sequentially or in parallel.

[0022] See Figure 1 This is a schematic diagram of a multi-antenna, multi-functional anechoic chamber for electromagnetic compatibility testing provided in the embodiments of this specification.

[0023] As an example, the anechoic chamber is constructed using steel plate splicing and steel structure support. The shielding shell measures 13m×11m×6m, and the internal dimensions after adding absorbing material are 12m×10m×5m. The shielding effectiveness is greater than 60dB below 1MHz and greater than 90dB above 1MHz.

[0024] The anechoic chamber includes a shielded room 1, a turntable 4, and multiple antennas arranged around the center of the turntable. The inner walls and top walls of the shielded room are covered with absorbing material 2. Exemplarily, the absorbing material includes ferrite absorbing material and wedge absorbing material. The ferrite absorbing material is installed on the four walls and top of the shielded room, while the wedge absorbing material is a rigid absorbing material installed on top of the ferrite absorbing material. The four walls and top of the shielded room are fully covered with absorbing material. This absorbing material configuration effectively absorbs electromagnetic waves, reduces reflections, and provides a suitable electromagnetic environment for different types of electromagnetic compatibility tests.

[0025] The turntable is located in the center of the floor inside the shielded room. For example, the turntable is a 2m diameter disc with a metal surface and a load-bearing capacity of ≥3000kg. The turntable's positioning accuracy is ≤±1 degree, its rotation speed is adjustable in at least four levels with a maximum speed of ≥2RPM, and it can rotate continuously. The turntable's height is the same as the reflective ground, and its surface is flush with the reflective ground. This design ensures that the device under test can be stably placed and subjected to omnidirectional rotational testing.

[0026] The floor inside the shielded room includes two different types of flooring: absorbing flooring (3) and reflective flooring (5). The reflective flooring is a metallic surface that provides a path for electromagnetic wave reflection. The absorbing flooring uses a raised floor structure and is installed on the floor of the shielded room. For example, the height of the raised flooring is no greater than 0.5m. Ferrite absorbing material is installed on the raised flooring, making the floor flush with the reflective flooring. Wedge-shaped absorbing material, which is movable and rigid, is placed on top of the ferrite. Its height is no greater than 0.3m, and the absorbing material is laid over a 10m × 5m area. This flooring design provides corresponding electromagnetic environment conditions for different test projects.

[0027] Inside the shielded room, multiple antennas, including receiving and transmitting antennas, are arranged around the center of the turntable. The maximum radiation direction of the main beam of each antenna is aligned with the center of the turntable, and each antenna has a different azimuth angle relative to the center of the turntable on the horizontal plane. This configuration ensures omnidirectional test coverage of the equipment under test.

[0028] At least one of the multiple antennas is positioned above the reflecting ground to perform radiated disturbance measurements. At least one of the multiple antennas is positioned above the absorbing ground to perform radiated spurious emissions testing or radiated immunity testing.

[0029] To facilitate understanding, the different tests compatible with the anechoic chamber in the embodiments of this specification are described.

[0030] Radiated interference testing measures the radiated interference emitted by electronic equipment (as a source of radiated interference). Radiated interference refers to the unwanted electromagnetic energy generated by the internal circuitry of a device or system during normal operation, which propagates through space in the form of electromagnetic waves and may constitute electromagnetic interference to other devices in the same electromagnetic environment.

[0031] Radiated spurious emissions (RSE) measurement measures unwanted emissions (such as harmonics and parasitic emissions) generated outside the operating frequency band by a wireless communication device while transmitting its normal communication signal. To measure SPE, the device under test (DUT) needs to transmit its normal communication signal (such as a mobile phone making a call). The transmit power of the DUT must be much stronger than the power of the unwanted signals it unintentionally emits outside the operating frequency band.

[0032] Radiated immunity testing is used to evaluate whether electronic or electrical equipment or systems can continue to maintain normal performance without loss of function, performance degradation or malfunction when subjected to external radio frequency electromagnetic interference.

[0033] Radiated disturbance testing and radiated spurious emissions testing require a receiving antenna, while radiated immunity testing requires a transmitting antenna.

[0034] In one embodiment of this description, at least one of a plurality of antennas is positioned above the reflecting ground to perform radiated disturbance tests.

[0035] Different standards for radiated interference testing at different frequency bands require different electromagnetic wave propagation environments. Specifically, for low-frequency radiated interference testing, an open test field is used. In an open test field, the electromagnetic wave propagation path includes the direct wave from the equipment to the receiving antenna, and the reflected wave that reaches the receiving antenna after being reflected by the ground. The receiving antenna measures the vector composite field of the direct and reflected waves.

[0036] To simulate the electromagnetic wave interference environment of an open test field in a darkroom, a benign reflective plane is required. In the embodiments of this specification, at least one of the multiple antennas is positioned above the reflective ground for low-frequency radiated interference testing. This ensures that during low-frequency radiated interference testing, the electromagnetic wave propagation path between the antenna and the turntable includes the reflection path provided by the reflective ground.

[0037] For radiated disturbance testing in the high-frequency band (e.g., 1 GHz ~ 6 GHz), as the frequency increases and the wavelength shortens, ground reflections produce highly complex and difficult-to-reproduce interference patterns, severely affecting the accuracy and comparability of the measurement results. Therefore, high-frequency testing is usually conducted in a free-space environment.

[0038] To simulate free space in a dark room, reflected waves need to be eliminated as much as possible. In the embodiments of this specification, at least one of the multiple antennas is positioned above the absorbing ground for high-frequency radiated interference testing.

[0039] The purpose of radiated spurious emissions testing is to accurately measure extremely weak, unwanted spurious signals generated outside the operating frequency band of wireless communication devices during operation. These spurious signals have very low power and are easily masked by reflected waves in the environment. If the corresponding test antenna is positioned above the reflecting ground, the direct signal emitted by the device and the signal reflected from the ground will interfere at the receiving antenna, leading to distorted measurement results.

[0040] The purpose of radiated immunity testing is to verify whether the device under test (DUT) can maintain normal operation in the presence of strong external electromagnetic interference. A known, uniform, and controllable interference electromagnetic field needs to be applied to the DUT. If the corresponding test antenna is positioned above the reflecting ground, the interference field emitted by the transmitting antenna will superimpose with the ground-reflected wave, forming a non-uniform and complex interference field in the area where the device is located. This will result in: the inability to establish a known and uniform field strength at the device location; and the inability to determine whether the device malfunction is due to the field strength specified in the standard or to a localized overload caused by the non-uniform field strength.

[0041] Therefore, in the embodiments of this specification, at least one of the multiple antennas is disposed above the absorbing ground to perform radiated spurious emissions testing or radiated immunity testing. This ensures that during the radiated spurious emissions testing or radiated immunity testing, the environment surrounding the electromagnetic wave propagation path between the antenna and the turntable is composed of absorbing ground and wall absorbing materials to absorb reflected waves.

[0042] In some embodiments of this specification, the receiving antenna includes: a first intermediate frequency (IF) receiving antenna and a first low-frequency (LHF) receiving antenna disposed above the reflective ground; wherein, the first IF receiving antenna disposed on the reflective ground is used to receive electromagnetic signals in the first IF band emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform radiated interference testing in the first IF band; the first LHF receiving antenna disposed on the reflective ground is used to receive electromagnetic signals in the first LHF band emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform radiated interference testing in the first LHF band.

[0043] For example, the first intermediate frequency receiving antenna is an auxiliary antenna. Figure 1 The first antenna and the first low-frequency receiving antenna are attached. Figure 1 The fifth antenna in the system.

[0044] The fifth antenna is a shielded ring antenna used for radiated interference measurements from 9kHz to 30MHz. Its size can be completely enclosed by a square with a side length of 60 cm. The fifth antenna is placed along the measurement axis, and the measurement reference point of the antenna is placed at the end of the measurement axis, which is 4m away from the center of the turntable. The measurement frequency range of the antenna is 9kHz to 30MHz. It is mounted on a fixed bracket, and the polarization direction of the antenna is manually adjusted.

[0045] The first antenna is a composite antenna used for radiated interference measurement from 30MHz to 1GHz. It is placed along the measurement axis, with the measurement reference point of the antenna placed at the end of the measurement axis, which is 4m from the center of the turntable. The measurement frequency range of the antenna is from 25MHz to 3GHz. It is installed on a 1m to 4m height-adjustable antenna tower. The horizontal and vertical polarization of the antenna can be switched automatically, and the height of the antenna can be raised and lowered automatically.

[0046] In some embodiments of this specification, the receiving antenna includes: a composite antenna disposed above the absorbing ground; the composite antenna is used to receive a first high-frequency electromagnetic signal emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform a radiated interference test in a first high-frequency band; or, it is used to receive a second high-frequency electromagnetic signal emitted by the device under test on the turntable when it is in a signal transmission state, so as to perform a radiated spurious emission test in a second high-frequency band.

[0047] In one embodiment, the composite antenna is positioned above the absorbing ground for radiated spurious emissions measurement in the 25MHz to 1GHz frequency band. It is placed along the measurement axis, with the measurement reference point located at the end of the measurement axis. The distance from the end of the measurement axis to the nearest absorbing material on the shielded room wall is 2m. The antenna's measurement frequency range is 25MHz to 3GHz. It is mounted on an antenna tower at a fixed height of 1.5m, and its horizontal and vertical polarizations can be automatically switched. This composite antenna can be used to receive a first high-frequency electromagnetic signal emitted by the device under test (DUT) on the turntable when it is in a non-signal transmission state to perform radiated interference testing in the first high-frequency band, and also to receive a second high-frequency electromagnetic signal emitted by the DUT on the turntable when it is in a signal transmission state to perform radiated spurious emissions testing in the second high-frequency band.

[0048] For example, the above-mentioned composite antenna is an appendix Figure 1 The fourth antenna in the example is a horn antenna used for measuring radiated emissions from 1 GHz to 6 GHz and radiated spurious emissions from 1 GHz to 18 GHz. It is placed along the measurement axis, with the measurement reference point of the antenna placed at the end of the measurement axis. The end of the measurement axis is 2 m away from the nearest shielding room wall absorbing material. The antenna's measurement frequency range is 1 GHz to 18 GHz. It is mounted on a 1 m to 4 m height-adjustable antenna tower. The horizontal and vertical polarization of the antenna can be automatically switched, and the antenna height can be automatically raised and lowered.

[0049] In one embodiment, the second low-frequency receiving antenna is also positioned above the absorbing ground to receive the second low-frequency electromagnetic signal emitted by the device under test on the turntable when it is in signal transmission state, so as to perform radiated spurious emissions testing in the second low-frequency band.

[0050] The aforementioned second low-frequency receiving antenna is an appendix. Figure 1 The second antenna is an example of a composite antenna used for radiated spurious emissions measurement from 25MHz to 1GHz. It is placed along the measurement axis, with the measurement reference point of the antenna placed at the end of the measurement axis. The end of the measurement axis is 2m away from the nearest shielding room wall absorbing material. The antenna's measurement frequency range is 25MHz to 3GHz. It is mounted on an antenna tower at a fixed height of 1.5m, and the horizontal and vertical polarization of the antenna can be automatically switched.

[0051] In one embodiment, the transmitting antenna is positioned above the absorbing ground to radiate an electromagnetic field onto the device under test on the turntable to perform a radiated immunity test. Exemplarily, the transmitting antenna is an auxiliary... Figure 1 The third antenna in the test. This transmitting antenna is a high-gain log-periodic antenna used for radiated immunity testing from 80MHz to 6GHz. It is placed along the measurement axis, with the measurement reference point at the end of the measurement axis. The antenna's test frequency range is 80MHz to 6GHz, with a continuous input power of not less than 200W, a radiated field strength of not less than 90V / m, and a length not greater than 2m. It is mounted on an antenna tower at a fixed height of 1.55m, and the antenna's horizontal and vertical polarization can be automatically switched.

[0052] In a preferred embodiment, a horn antenna is also included for radiated spurious emissions measurements from 18 GHz to 40 GHz.

[0053] For example, the transmitting antenna is an attachment Figure 2 The sixth antenna in the system. When conducting radiated immunity testing, this antenna is moved to the anechoic chamber. When conducting radiated spurious emissions measurements in the 18GHz to 40GHz high-frequency band, this antenna is placed in the adjacent... Figure 2 The location is shown. For example, the measurement reference point of the 6th antenna is 1m away from the edge of the turntable, the antenna's measurement frequency range is 18GHz to 40GHz, it is mounted on an antenna tower at a fixed height of 1.5m, and the antenna's horizontal and vertical polarization can be automatically switched.

[0054] The anechoic chamber operates as follows: The electromagnetic wave propagation path between at least one antenna positioned above a reflective surface and the turntable includes a reflection path provided by the reflective surface. This configuration is suitable for radiated disturbance measurements that utilize the ground reflection effect, simulating a real electromagnetic environment. Alternatively, the electromagnetic wave propagation path between at least one antenna positioned above an absorbing surface and the turntable is situated in an environment composed of absorbing surface and wall absorbing materials. This environment effectively absorbs reflected waves, creating near-free-space test conditions suitable for radiated stray emission testing and radiated immunity testing.

[0055] With this design, the anechoic chamber can perform a variety of different electromagnetic compatibility tests in the same space, including radiated disturbance tests, radiated spurious tests, and radiated immunity tests, which greatly improves testing efficiency and equipment utilization, while ensuring the accuracy and reliability of test results.

[0056] To ensure the safe operation of test personnel, extend the service life of sensitive test instruments, and completely eliminate the conduction and radiation crosstalk of high-power equipment to weak radio frequency measurement signals, in this embodiment, a dual-chamber auxiliary shielding system is attached to the outside of the main anechoic chamber (i.e., the main shielding chamber with absorbing material shown in the figure) used for electromagnetic compatibility testing.

[0057] Combined with appendix Figure 1 As shown, the dual-chamber auxiliary shielding system includes a shielding chamber 1 (control shielding chamber) and a shielding chamber 2 (power amplifier shielding chamber) arranged adjacent to each other. Both shielding chamber 1 and shielding chamber 2 share the outer shell sidewall with the main anechoic chamber, and a metal partition is also provided between shielding chamber 1 and shielding chamber 2.

[0058] Shielded Room 1 serves as the human-machine interface and signal processing center for the entire anechoic chamber system. Inside, core testing systems for radiated interference, radiated spurious emissions, and radiated immunity testing (such as high-sensitivity electromagnetic interference receivers, high-frequency spectrum analyzers, signal generators, etc.) and a test control computer are centrally located.

[0059] In terms of physical space, shielded room 1 has a first shielded room door that opens to the outside, allowing test engineers to enter and operate the equipment daily. Since the radiated spurious signals of communication equipment are very weak in certain high-frequency bands, placing the control terminal and sensitive receiving instruments in shielded room 1 can effectively prevent various civilian spurious electromagnetic waves (such as external communication base stations, broadcast signals, etc.) from interfering with the noise floor of the test instruments.

[0060] The shielded room 2 is equipped with a high-power test amplifier (such as a 100-watt or kilowatt-level RF power amplifier) ​​specifically designed for performing radiated immunity tests.

[0061] In terms of physical connection, shielded room 2 does not directly connect to the external environment, but is connected to shielded room 1 through a second shielded room door with an electromagnetic sealing strip. This access control layout not only facilitates test personnel to directly enter the power amplifier area (shielded room 2) from the control area (shielded room 1) for equipment debugging and maintenance, but also avoids the direct exposure of high-power transmission equipment to the outside.

[0062] Unlike shielded room 1, high-power RF amplifiers not only generate extremely high heat and acoustic noise from high-power cooling fans during operation, but their equipment casings and power cords often exhibit strong localized parasitic electromagnetic radiation leakage. Separating these high-noise, high-heat, and strong interference sources within shielded room 2 achieves strict dual isolation between them and the high-sensitivity measurement system within shielded room 1, both in terms of physical and electromagnetic environments.

[0063] In some embodiments of this specification, the floor inside the shielding room is a switchable floor structure. The switchable floor structure includes: a receiving pit disposed on the ground, a fixed reflective metal layer disposed at the bottom of the receiving pit, an electric lifting platform disposed within the receiving pit, and a metal translational cover plate slidably disposed at the opening of the receiving pit; The microwave absorbing material is installed on an electric lifting platform; When performing radiated stray emissions tests or radiated immunity tests, the metal sliding cover opens to both sides, and the electric lifting platform raises the absorbing material to a preset height to form an absorbing ground. When performing radiated disturbance measurements, the electric lifting platform lowers the absorbing material into the receiving pit, and the metal sliding cover closes, forming a continuous reflective surface with the surrounding ground.

[0064] Specifically, in order to further improve the testing efficiency of the anechoic chamber and avoid the time-consuming and positioning errors caused by manual handling and laying of absorbing materials, the floor inside the shielded chamber is designed as a switchable floor structure.

[0065] In ground areas requiring frequent standard switching, a accommodating pit of a certain depth (e.g., 0.6m~1.0m) is excavated or constructed using raised floors. A heavy-duty electric lifting platform is installed inside the accommodating pit, and a wave-absorbing surface composed of ferrite and wedge-shaped wave-absorbing material is integrally mounted on this platform. Simultaneously, a motor-driven metal sliding cover is installed at the horizontal opening of the accommodating pit. For example, the metal sliding cover is constructed from stainless steel or galvanized steel plates with a thickness of not less than 2mm.

[0066] The automatic switching works as follows: When entering the low-frequency radiated disturbance measurement mode, the electric lifting platform lowers the absorbing ground and completely sinks it into the accommodating pit; subsequently, the metal sliding cover slides along the horizontal rails and closes completely. After closing, the edge of the metal sliding cover makes tight contact with the surrounding reflective ground, at which point the entire anechoic chamber floor forms a flat and continuous reflective surface.

[0067] When entering the radiated spurious emissions, immunity test mode, or high-frequency radiated disturbance test mode, the metal sliding cover slides open to the sides or one side; then, the electric lifting platform starts, lifting the absorbing ground upwards until the bottom of the absorbing material is flush with the highest base plane. At this time, the wedge-shaped absorbing material is fully exposed in the shielded room space, absorbing excess electromagnetic reflections between the turntable and the antenna.

[0068] This structural design completely eliminates the tedious labor of manually laying the ground, and the physical reconstruction of the site characteristics can be completed in seconds with a single click.

[0069] In some embodiments of this specification, the multi-antenna multi-functional anechoic chamber also includes an antenna dynamic positioning system; The antenna dynamic positioning system includes linear guide rails embedded and laid out along multiple measurement axes, as well as self-driven antenna towers that correspond one-to-one with multiple antennas. The base of the self-driven antenna tower is snapped onto the corresponding linear guide rail, and the base integrates a servo drive motor and a laser rangefinder sensor. The servo drive motor is used to drive the self-driven antenna tower to move along the linear guide rail; the main ranging beam of the laser rangefinder is aligned with the center of the turntable to obtain the actual distance between the antenna's measurement reference point and the turntable center in real time, so as to form a position closed-loop control.

[0070] In electromagnetic compatibility testing of communication equipment, the required measurement distance varies depending on the frequency band and standard (e.g., 3m, 5m, 10m, etc.). Furthermore, for weak spurious signals in high-frequency bands (e.g., 18GHz~40GHz), it may be necessary to perform approximation measurements close to the near field (e.g., at a distance of less than 1m). To meet the flexible range adjustment requirements of multiple antennas, this system constructs an antenna dynamic positioning system.

[0071] Specifically, along the designed measurement axes 1 to 5 (e.g. Figure 2 As shown in the diagram, high-precision linear trackless guides or industrial-grade linear slide rails are embedded in the ground. For reflective ground areas, the metal shell of the guide rail is equipotentially connected to the reflective ground to avoid parasitic radiation; for absorbing ground areas, the guide rail is embedded in the gaps between ferrite and wedge-shaped absorbing materials, and its surface is covered with a low-dielectric-constant absorbing cover plate to prevent damage to local absorbing performance.

[0072] Based on this, all existing antenna towers have been upgraded to self-driving antenna towers. The modular chassis of the antenna tower integrates an omnidirectional slider and an AC servo drive motor. In addition, a high-precision laser rangefinder sensor is installed at the front end of the antenna tower chassis, directly opposite the center of the turntable.

[0073] During testing, the control system issues the required measurement distance command (e.g., a distance of 3.00 meters from the turntable center), and the servo drive motor drives the antenna tower to move automatically along the linear guide rail of the measurement axis. During this movement, the laser rangefinder feeds back the actual physical distance between the measurement reference point and the geometric center of the turntable to the central control system in milliseconds, achieving closed-loop control with positioning accuracy within millimeter levels. This not only enables the automatic configuration of the optimal working distance for antennas of different frequency bands but also avoids the systematic errors caused by traditional manual measuring with a tape measure.

[0074] In some embodiments of this specification, the multi-antenna multi-functional anechoic chamber also includes an electromagnetic isolation and crosstalk suppression system; The electromagnetic isolation and crosstalk suppression system includes: a retractable electromagnetic isolation baffle disposed between adjacent measurement axes; The retractable electromagnetic isolation barrier includes a lifting base and an isolation plate body. The isolation plate body is composed of a conductive fabric layer and a ferrite absorbing sheet attached to its surface. Under test conditions, when two or more antennas are working simultaneously, the lifting base drives the isolation plate body to rise, blocking the direct coupling electromagnetic waves between adjacent antennas.

[0075] In this manual, since multiple antennas are arranged in a ring around the turntable in a shielded room, in order to support the parallel testing of two antennas and to avoid near-field coupling and crosstalk in the receiving channel caused by the parallel testing of two antennas, this anechoic chamber is equipped with an electromagnetic isolation and crosstalk suppression system.

[0076] A retractable electromagnetic isolation baffle is installed on the spatial side. A pneumatic or electrically operated lifting base is concealed beneath the platform along adjacent measurement axes (especially between high-frequency and anti-interference antennas in the absorbing ground area), upon which a one-piece molded isolation baffle body is mounted. The inner layer of the isolation baffle body is made of highly conductive radiation-shielding fabric, and the outer layer is covered with a broadband ferrite flexible absorbing sheet. The baffle can be raised from the ground as needed for testing, forming a physical barrier of a certain height, capable of cutting off some of the antenna sidelobe direct waves, such as the sidelobe direct wave from the 3rd antenna to the 4th antenna.

[0077] The isolation mechanism using spatial baffles ensures that even when high-field-strength RF immunity transmitters and high-sensitivity spurious receivers coexist at close range within the same anechoic chamber, the isolation system prevents the noise floor of the test instruments from rising, thus laying the foundation for efficient parallel hybrid testing.

[0078] This specification also provides an electromagnetic compatibility testing system, including: an anechoic chamber and multiple testing instrument systems; the anechoic chamber includes: a shielded room, the inner walls and top walls of which are provided with absorbing materials; a turntable, located in the central area of ​​the floor inside the shielded room; the floor inside the shielded room includes an absorbing surface and a reflective surface; multiple antennas are arranged around the center of the turntable inside the shielded room; the multiple testing instrument systems include at least one radiated disturbance measurement system, at least one radiated spurious emission measurement system, and at least one radiated immunity testing system; at least one antenna deployed above the reflective surface is connected to the radiated disturbance measurement system, and at least one antenna deployed above the absorbing surface is connected to either the radiated spurious emission measurement system or the radiated immunity testing system.

[0079] The system includes three main components: a radiated disturbance measurement system for measuring electromagnetic disturbance signals radiated by the device under test (DUT), capable of accurate measurement within the frequency range of 30MHz to 6GHz; a radiated spurious emission measurement system for measuring spurious emissions from transmitting equipment, covering a wide frequency band of 25MHz to 40GHz; and a radiated immunity test system for testing the DUT's immunity to external electromagnetic fields, capable of generating a radiated field strength of not less than 90V / m within the 80MHz to 6GHz frequency band.

[0080] At least one antenna, deployed above the reflective ground, is connected to the radiated emissions measurement system. This configuration utilizes the metallic properties of the reflective ground to create a reflective field environment, simulating open-field testing conditions, enabling the radiated emissions measurement to accurately reflect the electromagnetic radiation characteristics of the device under test in its actual operating environment. The combination of the reflective ground and the antenna enhances the measurement signal and improves measurement accuracy.

[0081] At least one antenna, deployed above an absorbing ground surface, is connected to either a radiated spurious emissions measurement system or a radiated immunity test system. The absorbing ground surface, through a combination of ferrite and wedge absorbing materials, effectively absorbs excess electromagnetic wave reflections, reducing multipath effects and reflection interference in the test environment. This configuration is particularly suitable for radiated spurious emissions measurements because the absorbing environment reduces background noise and improves measurement accuracy. For radiated immunity testing, the absorbing environment ensures the uniformity of the test field strength, avoiding the influence of reflected waves on the test results.

[0082] This electromagnetic compatibility (EMC) testing system, through the rational configuration of different types of ground surfaces and corresponding antenna systems, can complete various types of EMC tests within the same anechoic chamber, greatly improving testing efficiency and equipment utilization. The partitioned design of reflective and absorbing ground surfaces allows the system to provide appropriate electromagnetic environments according to different testing requirements, ensuring the accuracy and reliability of various tests.

[0083] It should be understood that in the various embodiments of this specification, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this specification.

[0084] It should also be understood that, in the embodiments of this specification, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this specification generally indicates that the preceding and following related objects have an "or" relationship.

[0085] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed in this specification can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of each example have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this specification.

[0086] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0087] In the several embodiments provided in this specification, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, devices, or units, or they may be electrical, mechanical, or other forms of connection.

[0088] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of the embodiments described in this specification, depending on actual needs.

[0089] Furthermore, the functional units in the various embodiments of this specification can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0090] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this specification, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this specification. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0091] This specification uses specific embodiments to illustrate the principles and implementation methods of this specification. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this specification. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this specification. Therefore, the content of this specification should not be construed as a limitation of this specification.

Claims

1. A multi-antenna, multi-functional anechoic chamber for electromagnetic compatibility testing, characterized in that, include: The shielded room has wave-absorbing materials installed on its inner walls and top walls; A turntable is located in the central area of ​​the floor inside the shielded room. The floor inside the shielding room includes both absorbing and reflective surfaces. Inside the shielded room, multiple antennas are arranged around the center of the turntable, with at least one of the antennas positioned above the reflecting ground to perform radiated disturbance measurements. At least one of the multiple antennas is positioned above the absorbing ground to perform radiated spurious emissions testing or radiated immunity testing.

2. The anechoic chamber according to claim 1, characterized in that, The maximum radiation direction of the main beam of each of the multiple antennas is aligned with the center of the turntable, and the multiple antennas have different azimuth angles relative to the center of the turntable on the horizontal plane.

3. The anechoic chamber according to claim 1, characterized in that, The multiple antennas include: At least one receiving antenna is provided for receiving electromagnetic signals from the device under test on the turntable in order to perform radiated interference testing or radiated spurious emissions testing. At least one transmitting antenna is used to radiate an electromagnetic field to the device under test on the turntable in order to perform a radiated immunity test.

4. The anechoic chamber according to claim 3, characterized in that, The receiving antenna includes: A first intermediate frequency receiving antenna and a first low frequency receiving antenna are disposed above the reflective ground; The first intermediate frequency receiving antenna, which is set on the reflective ground, is used to receive electromagnetic signals in the first intermediate frequency band emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform radiated interference test in the first intermediate frequency band. A first low-frequency receiving antenna is installed on the reflective ground to receive electromagnetic signals in the first low-frequency band emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform radiated interference tests in the first low-frequency band.

5. The anechoic chamber according to claim 3, characterized in that, The receiving antenna includes a composite antenna disposed above the absorbing ground surface; The composite antenna is used to receive a first high-frequency electromagnetic signal emitted by the device under test on the turntable when it is in a non-signal transmission state, so as to perform radiated interference testing in the first high-frequency band. Alternatively, it can be used to receive a second high-frequency electromagnetic signal emitted from the device under test on the turntable when it is in signal transmission state, in order to perform a second high-frequency band radiated spurious emission test.

6. The anechoic chamber according to claim 3, characterized in that, The receiving antenna includes: A second intermediate frequency receiving antenna and a second low frequency receiving antenna are disposed above the absorbing ground. The second intermediate frequency receiving antenna is used to receive the second intermediate frequency electromagnetic signal emitted by the device under test on the turntable when it is in the signal transmission state, so as to perform radiated spurious emissions testing in the second intermediate frequency band. The second low-frequency receiving antenna is used to receive the second low-frequency electromagnetic signal emitted by the device under test on the turntable when it is in signal transmission state, so as to perform radiated spurious emissions testing in the second low-frequency band.

7. The anechoic chamber according to claim 1, characterized in that, The electromagnetic wave propagation path between at least one antenna positioned above the reflective ground and the turntable includes a reflection path provided by the reflective ground; The environment in which the electromagnetic wave propagation path between at least one antenna positioned above the absorbing ground and the turntable is located is composed of the absorbing ground and wall absorbing materials to absorb reflected waves.

8. An electromagnetic compatibility testing system, characterized in that, include: An anechoic chamber and multiple testing instrument systems; The anechoic chamber includes: a shielded room, the inner walls and top walls of which are provided with wave-absorbing material; a turntable, located in the central area of ​​the floor inside the shielded room; the floor inside the shielded room includes wave-absorbing floor and reflective floor. Multiple antennas are arranged around the center of the turntable inside the shielded room; The multiple test instrument systems include at least one radiated disturbance measurement system, at least one radiated stray emission measurement system, and at least one radiated immunity test system. At least one antenna deployed above the reflective ground is connected to the radiated disturbance measurement system, and at least one antenna deployed above the absorbing ground is connected to the radiated spurious emissions measurement system or the radiated immunity test system.

9. The testing system according to claim 8, characterized in that, include: The multiple antennas include: At least one receiving antenna is provided for receiving electromagnetic signals from the device under test on the turntable in order to perform radiated interference testing or radiated spurious emissions testing. At least one transmitting antenna is used to radiate an electromagnetic field to the device under test on the turntable in order to perform a radiated immunity test.

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