High-precision electromagnetic detection device

Abstract

The invention discloses a high-precision electromagnetic detection device, which belongs to the technical field of radiation emission testing and comprises a movable base, a mast is arranged on the upper surface of the movable base, a linear module is vertically arranged in the mast, a fixing plate is mounted on the surface of a sliding table of the linear module, and an antenna assembly is mounted on the upper surface of the fixing plate. By arranging the antenna assembly, the physical length of the antenna can be dynamically adjusted, half-wavelength resonance conditions of different test frequency bands can be matched in real time, dynamic impedance matching is achieved in continuous scanning, polarization switching can be completed through electric control in the static state of the physical structure by arranging the horizontal polarization unit and the vertical polarization unit, and the test efficiency is improved. Cable abrasion, phase instability and vibration interference caused by mechanical rotation are avoided, the measurement consistency is guaranteed, rapid complete polarization scanning is supported, the test efficiency and precision are effectively improved, electromagnetic reflection interference can be restrained through annular scattering ribs arranged on the surface of the mast, and the measurement accuracy is further enhanced.

Description

Technical Field

[0001] This invention relates to the field of radiation emission testing technology, and in particular to a high-precision electromagnetic detection device. Background Technology

[0002] In the electromagnetic compatibility (EMC) certification of electronic and electrical products, radiated emission (RE) testing is a mandatory step. Its purpose is to measure whether the intensity of electromagnetic noise unintentionally emitted by the equipment meets the regulatory limits. As a key detection device for capturing these noise signals, the performance of the test antenna directly determines the accuracy of the measurement results. Based on testing standards such as CISPR 16 and ANSI C63.4 (hereinafter referred to as standards), RE testing needs to cover a wide frequency band from 30MHz to several GHz (such as 6GHz). However, the physical size of traditional biconical antennas and log-periodic antennas is closely related to their resonant frequency, making it difficult for a single antenna to maintain uniform sensitivity and excellent voltage standing wave ratio throughout the entire frequency band. Therefore, the laboratory must be equipped with multiple antennas and manually replaced by RF switches or in an anechoic chamber. This not only greatly reduces the testing efficiency, but also introduces uncontrollable impedance changes and measurement uncertainties due to repeated plugging and unplugging of connectors and cable movement, thus affecting the testing accuracy. The standard requires that the vertical and horizontal polarization field strengths be measured separately. The current mainstream solution is to use a mechanical rotation mechanism to drive the antenna to switch polarization by 90°. This mechanical movement will cause the RF cable of the test antenna to twist. The RF cable that rotates with the antenna is prone to phase instability during repeated twisting, which will destroy the consistency of signal transmission and is not conducive to high-precision repeatability certification testing. To address these issues, a high-precision electromagnetic detection device is proposed. Summary of the Invention

[0003] The purpose of this invention is to solve the comprehensive technical problems existing in the radiated emission testing devices in the prior art when performing wideband testing, full polarization measurement and dynamic impedance matching, and to propose a high-precision electromagnetic detection device.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: A high-precision electromagnetic detection device includes a movable base, a mast on the upper surface of the movable base, a linear module vertically arranged inside the mast, a fixing plate mounted on the slide surface of the linear module, an antenna assembly mounted on the upper surface of the fixing plate, the antenna assembly including a base, a cable at the rear end of the base, a telescopic component and a flexible circuit radiator at the front end of the base, and an end cap mounted on the end of the telescopic component away from the base. The telescopic assembly includes a telescopic motor, a positioning sleeve, and a threaded sleeve disposed within the base. The positioning sleeve is fixedly installed at one end of the base near the fixed plate. A positioning key is provided inside the positioning sleeve. The telescopic motor is connected to the threaded sleeve via a synchronous wheel mechanism. The threaded sleeve is installed inside the base via a rotating shaft. A spline screw shaft is provided inside the threaded sleeve. One end of the spline screw shaft is fixedly connected to the inner sidewall of the end cover. The other end of the spline screw shaft passes through the threaded sleeve and the positioning sleeve and is located outside the base. The shaft of the spline screw shaft is provided with a synchronous opening and closing mechanism. Multiple air bladders are provided on the outer sidewall of the synchronous opening and closing mechanism. The outer peripheral walls of the multiple air bladders are covered with a corrugated skin. The flexible circuit radiator includes a horizontally polarized unit and a vertically polarized unit arranged in a cylindrical shape. A dielectric isolation layer is provided between the horizontally polarized unit and the vertically polarized unit. A dielectric support layer is bonded to the inner wall of the horizontally polarized unit, and a dielectric protective layer is bonded to the outer wall of the vertically polarized unit.

[0005] Preferably, the outer wall of the mast is fixedly equipped with circumferentially radiating ribs arranged in a wave shape.

[0006] Preferably, the synchronous opening and closing mechanism includes a plurality of synchronous actuation rings arranged at equal intervals. The outer sidewalls of adjacent synchronous actuation rings are fixedly connected to the airbag. The inner sidewalls of the synchronous actuation rings are provided with connecting keys that match the spline screw shaft. The synchronous actuation rings are connected to the spline screw shaft key through the connecting keys. Synchronous springs are provided between the synchronous actuation rings.

[0007] Preferably, the airbag is configured as an annular shape, and an mounting plate is fixedly connected to the inner sidewall of the airbag for connecting the airbag to the synchronous actuation ring. The airbag is detachably connected to the outer sidewall of the synchronous actuation ring through the mounting ring, and an mounting ring is fixedly connected to the outer sidewall of the airbag.

[0008] Preferably, the horizontal polarization unit is configured as a ring-shaped, strip-shaped flexible circuit board, and a horizontal polarization circuit arranged in a serpentine pattern is installed inside the horizontal polarization unit. Multiple horizontal polarization units are bridged by the flexible circuit, and the density of the horizontal polarization circuit in the horizontal polarization unit decreases sequentially from the base to the end cover, forming an electrical cone.

[0009] Preferably, the shape and connection method of the vertical polarization unit are the same as those of the horizontal polarization unit, and a vertical polarization circuit arranged in a zigzag pattern is installed inside the vertical polarization unit. The arrangement of the vertical polarization circuit is the same as that of the horizontal polarization circuit.

[0010] Preferably, the dielectric isolation layer is a polyimide film to reduce electromagnetic energy coupling between the horizontally polarized circuit and the vertically polarized circuit, and to prevent short circuits caused by direct contact between the circuits.

[0011] Preferably, the dielectric support layer and the dielectric protective layer are made of polyolefin foam to ensure the consistency of impedance of the flexible circuit radiator under different stretching states.

[0012] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By setting up an antenna assembly and combining a telescopic component with a synchronous opening and closing mechanism, the present invention realizes the dynamic adjustment of the physical length of the antenna, enabling it to match the half-wavelength resonance conditions of different test frequency bands in real time and complete dynamic impedance matching during continuous scanning, which significantly broadens the effective working bandwidth of the antenna and improves frequency adaptability.

[0013] 2. By setting up horizontal and vertical polarization units, this invention achieves electrically controlled polarization switching in a static physical state, avoiding cable wear, phase instability, and vibration interference caused by mechanical rotation. This not only improves measurement consistency but also supports rapid full polarization measurement, thereby enhancing testing efficiency and accuracy.

[0014] 3. By setting up circumferential scattering ribs, the present invention can suppress electromagnetic reflection interference from the mast, thereby further enhancing measurement accuracy. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of a high-precision electromagnetic detection device proposed in this invention. Figure 2 This is a schematic diagram of the antenna assembly in the retracted state of a high-precision electromagnetic detection device proposed in this invention; Figure 3 This is a schematic diagram of the internal structure of the antenna assembly in a high-precision electromagnetic detection device proposed in this invention; Figure 4 This is a cross-sectional view of the internal structure of the antenna assembly in a high-precision electromagnetic detection device proposed in this invention; Figure 5 This is a structural assembly diagram of the positioning sleeve, threaded sleeve, and splined lead screw shaft in a high-precision electromagnetic detection device proposed in this invention; Figure 6 This is a structural assembly diagram of the synchronous actuation ring and synchronous spring in a high-precision electromagnetic detection device proposed in this invention; Figure 7 This is a schematic diagram of the synchronous actuation ring and flexible circuit radiator in a high-precision electromagnetic detection device proposed in this invention. Figure 8 This is a structural assembly diagram of the horizontal polarization unit, dielectric isolation layer, and vertical polarization unit in a high-precision electromagnetic detection device proposed in this invention. Figure 9 This is a schematic diagram of the horizontal polarization circuit and the vertical polarization circuit in a high-precision electromagnetic detection device proposed in this invention.

[0016] In the diagram: 1. Movable base; 2. Mast; 3. Fixing plate; 4. Base; 5. End cap; 6. Positioning sleeve; 7. Threaded sleeve; 8. Splined screw shaft; 9. Airbag; 10. Pleated skin; 11. Horizontal polarization unit; 1101. Horizontal polarization circuit; 12. Vertical polarization unit; 1201. Vertical polarization circuit; 13. Dielectric isolation layer; 14. Dielectric support layer; 15. Dielectric protective layer; 16. Circular scattering rib; 17. Synchronous actuation ring; 18. Synchronous spring; 19. Mounting ring. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0018] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] Example, refer to Figures 1 to 9 A high-precision electromagnetic detection device includes a movable base 1, a mast 2 on the upper surface of the movable base 1, a linear module vertically arranged inside the mast 2, a fixing plate 3 installed on the slide surface of the linear module, an antenna assembly installed on the upper surface of the fixing plate 3, the antenna assembly including a base 4, a cable at the rear end of the base 4, a telescopic component and a flexible circuit radiator at the front end of the base 4, and an end cap 5 installed at the end of the telescopic component away from the base 4. The telescopic assembly includes a telescopic motor, a positioning sleeve 6, and a threaded sleeve 7 disposed in the base 4. The positioning sleeve 6 is fixedly installed at one end of the base 4 near the fixed plate 3. The positioning sleeve 6 is provided with a positioning key. The telescopic motor is connected to the threaded sleeve 7 through a synchronous wheel mechanism. The threaded sleeve 7 is installed in the base 4 through a rotating shaft. The threaded sleeve 7 is provided with a spline screw shaft 8. One end of the spline screw shaft 8 is fixedly connected to the inner side wall of the end cover 5. The other end of the spline screw shaft 8 passes through the threaded sleeve 7 and the positioning sleeve 6 and is located outside the base 4. The rod of the spline screw shaft 8 is provided with a synchronous opening and closing mechanism. The outer side wall of the synchronous opening and closing mechanism is provided with multiple airbags 9. The outer peripheral wall of the multiple airbags 9 is covered with a pleated skin 10. The flexible circuit radiator includes a horizontally polarized unit 11 and a vertically polarized unit 12 arranged in a cylindrical shape. A dielectric isolation layer 13 is provided between the horizontally polarized unit 11 and the vertically polarized unit 12. The dielectric isolation layer 13 serves as both an adhesive and an insulating layer. A dielectric support layer 14 is bonded to the inner wall of the horizontally polarized unit 11, and a dielectric protective layer 15 is bonded to the outer wall of the vertically polarized unit 12. The dielectric protective layer 15 and the dielectric support layer 14 are made of the same material. The dielectric protective layer 15 is used to prevent the skin from abrading the vertically polarized unit 12 during operation.

[0021] The advantages of using the above-mentioned flexible circuit radiator are that the flexible circuit radiator performs axial extension through the telescopic component, so that its physical length can match the half-wavelength resonance condition of the target test frequency band. By adjusting the telescopic amount in real time, dynamic impedance matching can also be achieved during continuous scanning. By setting the vertical polarization unit 12 and the horizontal polarization unit 11, in conjunction with the built-in RF switch network, polarization electronic control switching can be achieved when the physical structure is stationary. This can avoid wear and phase instability of long cables during repeated twisting, and also avoid interference caused by rotational vibration to high-precision measurement, ensuring the consistency of signal transmission. Full polarization measurement can be completed by electrical signal command alone.

[0022] It should be noted that the mobile base 1, the linear module, and the RF switch network are all existing technologies.

[0023] Furthermore, a wave-shaped circumferential scattering rib 16 is fixedly installed on the outer wall of the mast 2. The wave-shaped curved surface of the circumferential scattering rib 16 can disperse the residual electromagnetic reflection energy, thereby reducing the electromagnetic pollution of the mast 2 itself to the test environment. Furthermore, the synchronous opening and closing mechanism includes multiple synchronous actuation rings 17 arranged at equal intervals. The outer side wall of the synchronous actuation ring 17 is fixedly connected to the airbag 9. The inner side wall of the synchronous actuation ring 17 is provided with a connecting key that matches the spline screw shaft 8. The synchronous actuation ring 17 is connected to the spline screw shaft 8 by the connecting key to form radial positioning, so that the synchronous actuation ring 17 can slide along the axis of the spline screw shaft 8. A synchronous spring 18 is provided between adjacent synchronous actuation rings 17. It should be noted that the deformation of the synchronizing spring 18 does not occur instantaneously across all the synchronizing springs 18, but rather begins from the compressed end and propagates sequentially to the other end. The release is the opposite, i.e., a "quasi-synchronous" action. This "quasi-synchronous" flexible transmission avoids the simultaneous action of all synchronizing actuating rings 17, which would otherwise cause significant stress to the flexible circuit bridge.

[0024] Furthermore, the airbag 9 is configured as an annular shape, and an mounting plate is fixedly connected to the inner sidewall of the airbag 9 for connecting the airbag 9 to the synchronous actuation ring 17. The airbag 9 is detachably connected to the outer sidewall of the synchronous actuation ring 17 via the mounting ring 19. The mounting ring 19 is fixedly connected to the outer sidewall of the airbag 9, which can provide a mounting plane for the flexible circuit radiator. It should be noted that the airbag 9 is used to dampen the vibration of the flexible circuit radiator during operation, and it is a replaceable component.

[0025] Furthermore, the horizontal polarization unit 11 is configured as a ring-shaped, strip-shaped flexible circuit board. The horizontal polarization unit 11 is equipped with a serpentine horizontal polarization circuit 1101. Multiple horizontal polarization units 11 are bridged by the flexible circuit. The density of the horizontal polarization circuit 1101 in the horizontal polarization unit 11 decreases sequentially from the base 4 to the end cover 5, forming an electrical cone. Furthermore, the shape and connection method of the vertical polarization unit 12 are the same as those of the horizontal polarization unit 11. The vertical polarization unit 12 is equipped with a vertical polarization circuit 1201 arranged in a "zigzag" shape. The arrangement of the vertical polarization circuit 1201 is the same as that of the horizontal polarization circuit 1101. The further advantage of adopting the above is that, through the combined action of the horizontal polarization unit 11 and the vertical polarization unit 12, the horizontal polarization circuit 1101 adopts a serpentine routing pattern with an electrical conical layout, and the vertical polarization circuit 1201 adopts a zigzag routing pattern with the same gradient structure. This allows the antenna assembly to maintain the mechanical stability of a cylindrical shape while obtaining the wideband impedance characteristics of a conical antenna, thereby achieving dynamic synergistic optimization of the antenna's physical structure and electromagnetic performance.

[0026] Furthermore, the dielectric isolation layer 13 is configured as a polyimide film to reduce electromagnetic energy coupling between the horizontal polarization circuit 1101 and the vertical polarization circuit 1201, and to prevent short circuits caused by direct contact between the circuits. Furthermore, the dielectric support layer 14 and the dielectric protective layer 15 are made of polyolefin foam to ensure the consistency of impedance of the flexible circuit radiator under different expansion and contraction states. Through the synergistic effect of the dielectric isolation layer 13 and the support layer, the high isolation between the dual polarization channels is ensured, and the consistency of characteristic impedance of the antenna is maintained during the expansion and contraction process, thereby improving the test efficiency and accuracy. When using this invention, the operator moves the mobile base 1 to the predetermined measurement point and mechanically locks it. Then, the operation control system starts the linear module inside the mast 2, driving the antenna assembly to rise and fall to the target test height. During the test, the telescopic component precisely adjusts the physical length of the flexible circuit radiator according to the requirements of the current test frequency band. During the extension process, the telescopic motor drives the threaded sleeve 7 to rotate, and the rotational motion is converted into the linear motion of the spline screw shaft 8 through the threaded engagement, which drives the synchronous opening and closing mechanism to move axially, so that the end cover 5 moves away. At this time, multiple synchronous actuation rings 17 are connected to the spline screw shaft 8 by the connecting key on the inner side, and slide synchronously (quasi-synchronously) along the axis under the elastic force of the synchronous spring 18. During the retraction process, the telescopic motor drives in the opposite direction, and the end cover 5 compresses the synchronous spring 18 to retract synchronously. During testing, the horizontal polarization unit 11 and the vertical polarization unit 12 are quickly switched via an RF switching network, enabling full polarization measurement without altering the antenna's physical orientation. Throughout the test, the electromagnetic reflection of the mast 2 itself is suppressed by the circumferential scattering rib 16, while the airbag 9 provides vibration damping, ensuring stable electrical performance and measurement accuracy even during complex mechanical movements. All measurement data is ultimately transmitted in real time to the data processing system via a cable passing through the fixed plate 3 until the radiated emission test is completed.

[0027] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-precision electromagnetic detection device, comprising a movable base (1), characterized in that, The upper surface of the mobile base (1) is provided with a mast (2), and a linear module is vertically arranged inside the mast (2). A fixing plate (3) is installed on the slide surface of the linear module. An antenna assembly is installed on the upper surface of the fixing plate (3). The antenna assembly includes a base (4). A cable is provided at the rear end of the base (4). A telescopic component and a flexible circuit radiator are provided at the front end of the base (4). An end cap (5) is installed at the end of the telescopic component away from the base (4). The telescopic assembly includes a telescopic motor, a positioning sleeve (6), and a threaded sleeve (7) disposed in the base (4). The positioning sleeve (6) is fixedly installed at one end of the base (4) near the fixing plate (3). The positioning sleeve (6) is provided with a positioning key. The telescopic motor is connected to the threaded sleeve (7) through a synchronous wheel mechanism. The threaded sleeve (7) is installed in the base (4) through a rotating shaft. The threaded sleeve (7) is provided with a spline screw shaft (8). One end of the spline screw shaft (8) is fixedly connected to the inner side wall of the end cover (5). The other end of the spline screw shaft (8) passes through the threaded sleeve (7) and the positioning sleeve (6) and is located outside the base (4). The rod of the spline screw shaft (8) is provided with a synchronous opening and closing mechanism. The outer side wall of the synchronous opening and closing mechanism is provided with multiple airbags (9). The outer peripheral wall of the multiple airbags (9) is covered with a wrinkled skin (10). The flexible circuit radiator includes a horizontally polarized unit (11) and a vertically polarized unit (12) arranged in a cylindrical shape. A dielectric isolation layer (13) is provided between the horizontally polarized unit (11) and the vertically polarized unit (12). A dielectric support layer (14) is bonded to the inner wall of the horizontally polarized unit (11), and a dielectric protective layer (15) is bonded to the outer wall of the vertically polarized unit (12).

2. The high-precision electromagnetic detection device according to claim 1, characterized in that, The outer wall of the mast (2) is fixedly equipped with circumferential scattering ribs (16) arranged in a wave shape.

3. The high-precision electromagnetic detection device according to claim 1, characterized in that, The synchronous opening and closing mechanism includes multiple synchronous actuation rings (17) arranged at equal intervals. The outer side wall of the synchronous actuation ring (17) is fixedly connected to the airbag (9). The inner side wall of the synchronous actuation ring (17) is provided with a connecting key that matches the spline screw shaft (8). The synchronous actuation ring (17) is connected to the spline screw shaft (8) by the connecting key. A synchronous spring (18) is provided between adjacent synchronous actuation rings (17).

4. The high-precision electromagnetic detection device according to claim 1, characterized in that, The airbag (9) is configured as an annular shape. An installation plate is fixedly connected to the inner sidewall of the airbag (9) for connecting the airbag (9) with the synchronous actuation ring (17). The airbag (9) is detachably connected to the outer sidewall of the synchronous actuation ring (17) through the installation ring (19). An installation ring (19) is fixedly connected to the outer sidewall of the airbag (9).

5. A high-precision electromagnetic detection device according to claim 4, characterized in that, The horizontal polarization unit (11) is configured as a ring-shaped, strip-shaped flexible circuit board. The horizontal polarization unit (11) is equipped with a serpentine horizontal polarization circuit (1101). Multiple horizontal polarization units (11) are bridged by the flexible circuit. The density of the horizontal polarization circuit (1101) in the horizontal polarization unit (11) decreases sequentially from the base (4) to the end cap (5), forming an electrical cone.

6. A high-precision electromagnetic detection device according to claim 5, characterized in that, The shape and connection method of the vertical polarization unit (12) are the same as those of the horizontal polarization unit (11). The vertical polarization unit (12) is equipped with a vertical polarization circuit (1201) arranged in a "zigzag" shape. The arrangement of the vertical polarization circuit (1201) is the same as that of the horizontal polarization circuit (1101).

7. A high-precision electromagnetic detection device according to claim 6, characterized in that, The dielectric isolation layer (13) is a polyimide film, which reduces electromagnetic energy coupling between the horizontal polarization circuit (1101) and the vertical polarization circuit (1201) and prevents short circuits caused by direct contact between the circuits.

8. A high-precision electromagnetic detection device according to claim 1, characterized in that, The dielectric support layer (14) and dielectric protection layer (15) are made of polyolefin foam to ensure the consistency of impedance of the flexible circuit radiator under different stretching states.

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