Detection device

Abstract

The utility model is applied to the technical field of detection, and provides detection equipment, which comprises a shell, an antenna assembly, a shielding plate and a circuit unit, an accommodating cavity is formed in the shell; the antenna assembly, the shielding plate and the circuit unit are arranged in the accommodating cavity, the antenna assembly is arranged on one side of the shielding plate, and the circuit unit is arranged on the other side of the shielding plate; and the shielding plate is a component with an electromagnetic shielding function. The detection equipment provided by the utility model is high in detection precision, and reduces the false alarm rate.

Description

Technical Field

[0001] This utility model relates to the field of detection technology, specifically to a detection device. Background Technology

[0002] Detection equipment (such as nonlinear node detectors) often achieves harmonic detection by transmitting fundamental wave signals to the target object (such as electronic devices like mobile phones) and receiving the second and third harmonic signals radiated by the target object.

[0003] Since the circuit units of the detection equipment (such as radio frequency boards, baseband boards, etc.) also have the characteristics of the target object (such as nonlinear nodes), the circuit units of traditional detection equipment may also generate second and third harmonic signals under the influence of the fundamental wave signal when they are working.

[0004] Current small-scale detection devices are generally small in size. Their internal antennas and circuit units are usually located in the front probe. The second and third harmonics generated by the circuit unit may be received by the antenna. However, the harmonic signals generated by the circuit unit are noise signals for the detection device, which may affect the detection accuracy of the detection device. Utility Model Content

[0005] In view of this, the present invention provides a detection device to solve the problem that the second and third harmonics generated by the circuit unit of a traditional small detection device may be received by the antenna, thereby affecting the harmonic detection results of the detection device.

[0006] To achieve the above objectives, the present invention provides the following technical solutions:

[0007] A detection device includes: a housing, an antenna assembly, a shielding plate, and a circuit unit;

[0008] The shell has an internal cavity;

[0009] The antenna assembly, shielding plate, and circuit unit are housed within the cavity, with the antenna assembly on one side of the shielding plate and the circuit unit on the other side.

[0010] The shielding plate is a component with electromagnetic shielding function.

[0011] Optionally, the shielding plate is connected to or abuts against the inner wall of the receiving cavity, and divides the receiving cavity into a first chamber and a second chamber;

[0012] The antenna assembly is located in the first chamber, and the circuit unit is located in the second chamber.

[0013] Optionally, the detection device also includes a conductive element located between the shielding plate and the inner wall of the receiving cavity, and connected to the shielding plate and the inner wall respectively, wherein the conductive element has an electromagnetic shielding function.

[0014] Optionally, the conductive component is a conductive component formed by curing liquid conductive silver paste.

[0015] Optionally, the inner wall of the housing is provided with conductive paint, and the conductive paint is connected to the conductive component.

[0016] Optionally, the shielding plate is a metal plate.

[0017] Optionally, the antenna assembly includes: an antenna board, a transmitting antenna, a harmonic receiving antenna, and a filter board;

[0018] Both the transmitting antenna and the harmonic receiving antenna are mounted on the antenna plate.

[0019] The filter plate includes a substrate and a filter, with the substrate located between the antenna plate and the shielding plate;

[0020] The filter is disposed on the side of the substrate away from the antenna plate, and the filter is connected to the harmonic receiving antenna and the circuit unit respectively.

[0021] Optionally, the antenna assembly further includes: a first shielding cover; the first shielding cover is fitted onto the filter;

[0022] And / or,

[0023] The detection device further includes a second shielding cover, which covers at least a portion of the circuit unit.

[0024] Optionally, the circuit unit is provided with an RF insertion terminal, and the filter is provided with an RF mating terminal that is detachably electrically connected to the RF insertion terminal;

[0025] The shielding plate has through holes for the RF insertion end or RF mating end to pass through.

[0026] Optionally, the detection device further includes: a display module, a flexible circuit board, and conductive foam;

[0027] The display module is electrically connected to the circuit unit via a flexible circuit board;

[0028] Conductive foam covers at least a portion of the flexible circuit board.

[0029] Based on the above-described embodiment of the present invention, a detection device has an internal cavity within its housing, in which an antenna assembly, a shielding plate, and a circuit unit are disposed. The antenna assembly is disposed on one side of the shielding plate, and the circuit unit is disposed on the other side of the shielding plate. Because the shielding plate has electromagnetic shielding capabilities, even if the circuit unit generates second or third harmonic signals under the influence of the fundamental wave signal during operation of the detection device, the generated harmonic signals will be weakened or blocked by the shielding plate and will not leak to the side of the shielding plate where the antenna assembly is disposed. This avoids misjudgment caused by the antenna assembly receiving incorrect harmonic signals (harmonic signals generated by the circuit unit), thereby improving the detection accuracy of the detection device and reducing the false alarm rate. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0031] Figure 1 A schematic diagram of the detection device provided in the embodiment of this utility model;

[0032] Figure 2 A cross-sectional view of the detection device provided in an embodiment of this utility model;

[0033] Figure 3 Exploded view of the detection device provided in the embodiment of this utility model;

[0034] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0035] Figure 5 A schematic diagram showing the connection relationship between the antenna assembly, shielding plate, radio frequency board, and baseband board provided in an embodiment of this utility model;

[0036] Figure 6 This is a schematic diagram of the structure of the display module, baseband board, and radio frequency board provided in the embodiments of this utility model.

[0037] Figure label:

[0038] 1. Handle part;

[0039] 2. Probe section; 21. Housing; 211. Bottom cover; 212. Outer shell; 213. First chamber; 214. Second chamber; 22. Antenna assembly; 221. Antenna board; 222. Filter board; 2221. Substrate; 223. First shielding cover; 224. Push-in RF connector; 23. Shielding plate; 231. Gap; 24. Circuit unit; 241. RF board; 242. Baseband board;

[0040] 3. Display module;

[0041] 4. Flexible circuit board. Detailed Implementation

[0042] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0043] Currently, detection equipment is generally small in size. Its internal antenna components and circuit units are usually located in the front probe section. Since the circuit unit also has the properties of the target object (such as a nonlinear node), the circuit unit may also generate second and third harmonics under the influence of the fundamental signal. These harmonics may be received by the antenna, and since these harmonics are noise signals, they may affect the harmonic detection results of the detection equipment, making the detection equipment prone to false alarms and thus reducing the detection accuracy of the detection equipment.

[0044] To address the aforementioned problems, this utility model provides a detection device, see [link to relevant documentation]. Figures 1 to 6 , Figure 1 This is a schematic diagram of the detection device. The detection device may include: a housing 21, an antenna assembly 22, a shielding plate 23, and a circuit unit 24. The housing 21 has an internal cavity. The antenna assembly 22, the shielding plate 23, and the circuit unit 24 are disposed within the cavity, with the antenna assembly 22 on one side of the shielding plate 23 and the circuit unit 24 on the other side. In this embodiment, the shielding plate 23 is a component with electromagnetic shielding function.

[0045] If the detection equipment is Figure 2The antenna assembly 22 is positioned, for example, below the shielding plate 23, and the circuit unit 24 is positioned, for example, above the shielding plate 23 (where above and below refer to opposite sides). The circuit unit 24 can perform setting functions (such as demodulating, amplifying, and processing the signal transmitted by the antenna assembly 22) and includes related electronic components. The circuit unit 24 may include one or more circuit boards, such as an RF board 241 and a baseband board 242. Taking a nonlinear node detector as an example, the RF board 241 is mainly responsible for converting the baseband signal (such as the original low-frequency signal of the fundamental wave) transmitted from the baseband board 242 into a high-frequency fundamental wave signal and transmitting it through the antenna assembly 22. The RF board 241 can also receive the second and third harmonic signals reflected back from the target object transmitted by the antenna assembly 22, and after amplification, filtering, mixing, and other processing, obtain intermediate frequency / low-frequency signals, and send the intermediate frequency / low-frequency signals to the baseband board 242. The baseband board 242 is used to generate baseband signals and can also process received intermediate frequency / low frequency signals to identify the presence of a target object. The radio frequency board 241 and the baseband board 242 can be described in detail in the prior art. In other embodiments, the radio frequency board 241 and the baseband board 242 can also be combined into a single circuit board to simultaneously possess the aforementioned radio frequency and baseband processing functions.

[0046] like Figure 1 and Figure 3 As shown, in the detection device provided in this application embodiment, the housing 21 may further include: a bottom cover 211 and an outer shell 212. The outer shell 212 has an opening on one side, and the bottom cover 211 is connected to the opening on the outer shell 212 to close the receiving cavity inside the outer shell 212. The antenna assembly 22, the shielding plate 23, and the circuit unit 24 (e.g., the radio frequency board 241 and the baseband board 242) are located inside the receiving cavity.

[0047] Furthermore, to facilitate gripping by the user, one side of the housing 21 extends outward to form a handle 1, allowing the user to hold the detection device for detection work. The portion of the housing 21 excluding the handle 1 is the probe 2. The handle 1 can also have a hollow structure inside, where components such as a power supply can be installed, while the antenna assembly 22, shielding plate 23, etc., are located inside the probe 2.

[0048] The detection device provided in this embodiment of the invention, due to the electromagnetic shielding function of the shielding plate 23, isolates the antenna assembly 22 from the circuit unit 24 when the detection device is working. Thus, even if the circuit unit 24 generates second or third harmonic signals under the influence of the fundamental signal, the generated harmonic signals will be weakened or blocked by the shielding plate 23, and will not leak to the side of the shielding plate 23 where the antenna assembly 22 is located. This avoids misjudgment caused by the antenna assembly 22 receiving incorrect harmonic signals (such as harmonic signals generated by the circuit unit 24), thereby improving the detection accuracy of the detection device and reducing the false alarm rate.

[0049] Specifically, the shielding plate 23 can be a metal plate.

[0050] It should also be noted that aluminum is a commonly used electromagnetic shielding metal, characterized by its low price and low density, and is widely used in electromagnetic shielding. Therefore, considering both cost and shielding effectiveness, in this embodiment of the invention, the shielding plate 23 can be made of aluminum.

[0051] Optionally, the shielding plate 23 can be a plate-shaped component made of metal (e.g., copper, aluminum, iron, etc.) or a plate-shaped component made of other metal materials that can block electromagnetic signals. Those skilled in the art can choose according to their needs.

[0052] Specifically, refer to Figure 2 The shielding plate 23 is connected to or abuts against the inner wall of the receiving cavity, and divides the receiving cavity into a first chamber 213 and a second chamber 214.

[0053] Antenna assembly 22 is located in the first chamber 213, and circuit unit 24 is located in the second chamber 214.

[0054] It should be noted that the shielding plate 23 is installed inside the receiving cavity and is connected to or abuts against the inner wall of the receiving cavity. This can minimize the size of the gap 231 between the shielding plate 23 and the inner wall of the receiving cavity. In other words, it can reduce the size of the harmonic signal transmission path between components such as the radio frequency board 241, the baseband board 242 and the antenna assembly 22. This can reduce the probability that the harmonic signals generated by the circuit unit 24 are received by the antenna assembly 22 through the gap 231 between the shielding plate 23 and the housing 21. This further ensures the accuracy of the harmonic detection results of the detection equipment and reduces the false alarm rate.

[0055] It should also be noted that when the shielding plate 23 is connected to or abuts against the inner wall of the receiving cavity, there are two situations: there is a gap between the shielding plate 23 and the inner wall of the receiving cavity (caused by processing error), and there is no gap.

[0056] To further reduce the false alarm rate, in some embodiments of this application, for cases where gaps exist, the detection device may further include a conductive element (not shown in the figures), located between the shielding plate 23 and the inner wall of the receiving cavity. Figure 4 The conductive component is located at the gap 231 in the middle and is connected to the shielding plate 23 and the inner wall respectively. The conductive component has electromagnetic shielding function.

[0057] As can be seen from the above, during the processing of the shielding plate 23, due to unavoidable processing errors, and for ease of installation (the shielding plate 23 and the housing 21 are usually clearance fit), a gap 231 may exist after the shielding plate 23 and the housing 21 are assembled (e.g., Figure 4 (As shown). In this embodiment, a conductive element is filled between the shielding plate 23 and the inner wall of the housing 21 (at the gap 231). The conductive element has conductive properties. When the electromagnetic signal propagates between the conductive particles of the conductive element, it will continuously change its propagation direction, causing the energy of the electromagnetic signal to be continuously lost during multiple reflections and scattering processes, thereby converting the energy of the electromagnetic signal into other forms of energy such as heat energy, thus achieving the absorption of electromagnetic waves. In addition, when the electromagnetic signal reaches the surface of the conductive element, part of the electromagnetic signal will be reflected by the conductive surface of the conductive element. Combining the above two points, the conductive element placed at the gap 231 between the shielding plate 23 and the housing 21 can absorb and reflect the harmonic signals generated by the circuit unit 24. Therefore, the conductive element can effectively prevent the harmonic signals generated by the circuit unit 24 from being received by the antenna assembly 22 through the gap 231 between the shielding plate 23 and the housing 21, further ensuring the accuracy of the harmonic detection results of the detection device.

[0058] Furthermore, the conductive component can be a conductive component formed by curing liquid conductive silver paste.

[0059] Because liquid silver paste has good flow properties, it can be applied by spraying or other methods in situations where space is limited. It can easily reach all positions of the gap 231, so that after the liquid silver paste solidifies, it can effectively fill the entire gap 231 between the shielding plate 23 and the inner wall of the housing 21. This prevents the harmonic signals generated by the circuit unit 24 from being received by the antenna assembly 22 through the gap 231 between the shielding plate 23 and the housing 21, thereby further ensuring the accuracy of the harmonic detection results of the detection equipment.

[0060] One embodiment of this application uses solidified liquid conductive silver paste as a conductive component, which not only facilitates processing and reduces manufacturing difficulty, but also effectively fills the gap 231 between the shielding plate 23 and the inner wall of the shell 21.

[0061] In addition, the silver powder in the conductive silver paste has excellent conductivity. When an electromagnetic signal reaches the surface of the conductive silver paste, an induced current is generated on its surface. According to Lenz's law, the induced current generates a magnetic field opposite to the incident electromagnetic signal, thereby reflecting the electromagnetic signal and achieving a good electromagnetic shielding effect.

[0062] It should be noted that the conductive component can be formed by curing conductive silver paste, or it can be formed by laying other materials with electromagnetic shielding function. Those skilled in the art can choose according to their needs.

[0063] Specifically, the inner wall of the housing 21 is coated with conductive paint, and the conductive paint is connected to the conductive components.

[0064] In one specific embodiment, if the inner wall of the shielding plate 23 in contact with the probe section 2 is composed of the inner wall of the outer shell 212 and part of the inner wall of the bottom cover 211, in order to further improve the shielding effect on the antenna assembly 22, conductive paint is sprayed on both the inner wall of the outer shell 212 and the inner wall of the bottom cover 211 to form a conductive paint layer (not shown in the figure). The conductive paint layer, together with the shielding plate 23 and the conductive components in the aforementioned gap 231, forms a closed-loop shielding environment, so that the circuit unit 24 and the antenna assembly 22 are completely isolated and each is housed in a closed electromagnetic shielding environment to reduce leakage interference.

[0065] Conductive paint has both electrical conductivity and electromagnetic shielding properties. Its specific principle is the same as that of the conductive components mentioned above, so it will not be elaborated on here.

[0066] It should be noted that when the housing 21 does not possess conductive properties, conductive paint is sprayed onto the inner wall of the housing 21 to make it conductive. The shielding plate 23 has electromagnetic shielding capabilities, and the conductive components between the shielding plate 23 and the housing 21 are also conductive. This allows the conductive components, shielding plate 23, and housing 21 to work together to form a closed loop, creating a sealed electromagnetic shielding environment. This further completely cuts off the electromagnetic signal transmission path between the antenna assembly 22 and the circuit unit 24. The second and third harmonic signals generated by the circuit unit 24 are blocked within the second chamber 214, thus preventing the antenna assembly 22 from receiving these signals. Therefore, this avoids affecting the detection accuracy of the antenna assembly 22 and reduces the false alarm rate.

[0067] It should also be noted that in related technologies, antenna assemblies typically include: an antenna plate, a transmitting antenna, and a harmonic receiving antenna. Since both the transmitting and harmonic receiving antennas are mounted on the antenna plate, and the area of ​​the antenna plate is limited, the isolation between the transmitting and harmonic receiving antennas is poor. The fundamental frequency signal may couple from the harmonic receiving antenna to the receiving channel (e.g., reaching the filter). In some cases, such as when the amplitude of the fundamental frequency signal is large, the electronic components inside the filter may generate second and third harmonic signals under the influence of the fundamental frequency signal. These harmonic signals can cause the detection equipment to mistakenly identify the presence of a target object, resulting in a high false alarm rate.

[0068] Specifically, to solve the above problems, this embodiment provides the following solution. (See reference...) Figures 3 to 5 The antenna assembly may include: an antenna plate 221, a transmitting antenna (not shown in the figure), a harmonic receiving antenna (not shown in the figure), and a filter plate 222. The transmitting antenna and the harmonic receiving antenna are both disposed on the antenna plate 221. The filter plate 222 includes a substrate 2221 and a filter (not shown in the figure), with the substrate 2221 located between the antenna plate 221 and the shielding plate 23. The filter is disposed on the side of the substrate 2221 facing away from the antenna plate 221, and is connected to the harmonic receiving antenna and the circuit unit, respectively. The substrate 2221 may be a support plate for the filter, and may only have the filter disposed on it, or it may also have other components disposed on it.

[0069] In this embodiment, a filter is provided and connected to the harmonic receiving antenna. The filter allows wireless signals in the desired frequency band to pass through. Since the frequency of the harmonic signal is much higher than that of the fundamental signal, setting a filter corresponding to the frequency band of the harmonic signal can, ideally, filter out the fundamental signal, preventing the fundamental signal from generating harmonic signals at the filter and causing false alarms in the detection device.

[0070] Optionally, in this embodiment, the harmonic receiving antenna can be a second harmonic receiving antenna, a third harmonic receiving antenna, or both. Therefore, the filter can be connected to either the second or third harmonic receiving antenna, and those skilled in the art can configure it according to their needs.

[0071] Optionally, in this embodiment, the number of filters can be set to two, with the two filters connected to the second harmonic receiving antenna and the third harmonic receiving antenna, respectively.

[0072] Furthermore, since the fundamental wave signal may also couple to the receiving channel from the interface between the filter and the harmonic receiving antenna, meaning the fundamental wave signal might reach, for example, the filter, can be placed on the substrate 2221, specifically on the side of the substrate 2221 facing away from the antenna plate 221. This increases the distance between the filter interface and the transmitting antenna on the antenna plate 221, reducing the energy of the fundamental wave signal reaching the filter and thus preventing coupling to the receiving channel through the filter interface to some extent. Additionally, the substrate 2221 separates the filter from the antenna on the antenna plate 221, further weakening the fundamental wave signal as it passes through it. Overall, this significantly reduces the probability of the fundamental wave signal coupling to the receiving channel through the filter interface.

[0073] To further reduce the false alarm rate, in some embodiments of this application, reference is made to... Figure 5 The antenna assembly 22 may further include a first shielding cover 223. The first shielding cover 223 is disposed over the filter.

[0074] In addition to adjusting the setting position of the filter, a first shield 223 with electromagnetic shielding function can be installed on the outside of the filter. In this way, even if a fundamental wave signal reaches the filter, the harmonic signal generated by the fundamental wave signal at the filter will be blocked inside the first shield 223, thereby reducing the false alarm rate of the detection equipment.

[0075] Furthermore, it should be noted that although the filter has the function of filtering out the fundamental frequency signal, in some cases, the filter may not be able to completely filter out the fundamental frequency signal. The remaining fundamental frequency signal will continue to be transmitted in the receiving channel to the amplifier, mixer, and other electronic components in the circuit unit 24. These electronic components may also generate second and third harmonic signals under the influence of the fundamental frequency signal. These harmonic signals may cause the detection equipment to mistakenly believe that a target object is present, resulting in a high false alarm rate for the detection equipment.

[0076] In some embodiments, to address the aforementioned problems, the detection device may further include a second shield (not shown in the figure), which covers at least a portion of the circuit unit 24. By providing a second shield on the circuit unit 24, the second shield can cover electronic components with nonlinear nodes, such as amplifiers and mixers, within the circuit unit 24. This allows the second and third harmonic signals generated at these electronic components to be blocked within the second shield even if the filter does not completely remove the fundamental frequency, further ensuring the detection accuracy of the detection device and reducing the false alarm rate.

[0077] It should be noted that the second shielding cover may be placed only on the electronic components with nonlinear nodes, or it may be placed completely on the circuit unit 24. Those skilled in the art can select and adjust it according to actual needs.

[0078] In some embodiments, the first shield 223 and / or the second shield can be a metal shield.

[0079] In other embodiments, the first shield 223 and / or the second shield may be conductive shields made of other conductive materials.

[0080] Taking a nonlinear node detector as an example, when the detection equipment is working normally, all components need to work together. After the second and third harmonic receiving antennas receive the signal, they remove the noise signal through the filter, and then the processed signal needs to be transmitted to the radio frequency board 241 for the next round of processing.

[0081] As can be seen from the above, in order to avoid the fundamental wave signal of the transmitting antenna being coupled to the receiving channel through the second harmonic receiving antenna and the third harmonic receiving antenna and affecting the subsequent detection accuracy, a first shield 223 can be provided outside the filter. In order to avoid the first shield 223 affecting the connection between the filter and the radio frequency board 241, in some embodiments of this application, the circuit unit 24 (e.g., radio frequency board 241) is provided with a radio frequency insertion terminal, and the filter is provided with a radio frequency mating terminal that is detachably electrically connected to the radio frequency insertion terminal (the radio frequency mating terminal passes through the first shield 223).

[0082] The shielding plate 23 has through holes for the RF insertion end or RF mating end to pass through.

[0083] It should be noted that the RF insertion end and the RF mating end can be, for example, a small push-in RF connector 224 (i.e., SMP, RF coaxial connector). Since the second and third harmonic signals filtered by the filter board 222 need to pass through the shielding plate 23 for transmission, to achieve signal shielding during this transmission process, the RF insertion end and the RF mating end need to pass through the through-hole of the shielding plate 23 to achieve mating, thus forming a small push-in RF connector 224. Specifically, the RF insertion end can pass through the through-hole, the RF mating end can pass through the through-hole, or both the RF insertion end and the RF mating end can pass through the through-hole, i.e., mating occurs within the through-hole. All of these are within the scope of protection of this application.

[0084] SMP connectors typically employ a coaxial structure, with a central conductor used for signal transmission and an external shielding layer. This shielding layer is usually made of metal, such as copper or copper alloy. This metal shielding layer can enclose the internal signal transmission lines, forming a closed metal space, thereby achieving signal shielding during signal transmission.

[0085] In addition, when the RF insertion end and the RF mating end are connected, the shielding layer can be seamlessly connected to form a complete electromagnetic shield. This continuous shielding structure can prevent electromagnetic leakage and ensure the signal shielding effect of the entire link from the signal source to the load.

[0086] In some embodiments, reference Figure 6 The detection device may also include: display module 3, flexible circuit board 4 and conductive foam.

[0087] The display module 3 is electrically connected to the circuit unit 24 (e.g., baseband board 242) via the flexible circuit board 4 and is used to display the detection results.

[0088] Conductive foam covers at least a portion of the flexible circuit board 4.

[0089] It should be noted that, in this embodiment of the application, by setting up a display module 3 and electrically connecting the display module 3 to the circuit unit 24 through a flexible circuit board 4, the data detected by the detection device can be transmitted to the display module 3 for display through the flexible circuit board 4, which makes it convenient for users to directly obtain the corresponding detection data, greatly improving the practicality and convenience of the detection device.

[0090] However, since the display module 3 needs to be electrically connected to the circuit unit 24 via the flexible circuit board 4, and the flexible circuit board 4 is located on the side of the shielding plate 23 where the circuit unit 24 is located, the flexible circuit board 4 is directly exposed in the second chamber 214. The flexible circuit board 4 also generates harmonic signals during its operation, and these harmonic signals may leak into the first chamber 213 and be received by the antenna assembly 22, leading to false alarms. Alternatively, they may leak to the outside of the housing 21 of the detection device. Therefore, conductive foam can be provided outside the flexible circuit unit 24. Due to the conductive properties of the conductive foam, the electromagnetic signal will continuously change its propagation direction when propagating between the conductive particles or fibers inside the foam, causing the energy of the electromagnetic signal to be continuously lost during multiple reflections and scattering. Furthermore, when the electromagnetic signal reaches the surface of the conductive foam, a portion of the electromagnetic signal will be reflected on the conductive surface of the conductive foam. Therefore, by providing conductive foam, electromagnetic shielding of the flexible circuit board 4 can be effectively achieved, preventing harmonic signal leakage and avoiding false alarms from the detection device.

[0091] In some embodiments (not shown in the figure), conductive foam can completely cover the flexible circuit board 4.

[0092] Complete coverage of the flexible circuit board 4 with conductive foam means that the conductive foam is wrapped around the circumference of the flexible circuit board 4. Alternatively, both sides of the flexible circuit board 4 are covered with conductive foam, and the area of ​​the conductive foam is greater than or equal to the area of ​​the flexible circuit board 4.

[0093] In some embodiments, the conductive foam can be connected to the flexible circuit board 4 using conductive adhesive to prevent accidental detachment of the conductive foam. Those skilled in the art can select and adjust the connection method between the conductive foam and the flexible circuit board 4 according to actual needs. For example, they can also be connected by welding, crimping, or other methods.

[0094] Optionally, the detection device in this application embodiment may be, for example, a nonlinear node detector or other harmonic detection devices.

[0095] Taking a nonlinear node detector as an example, the nonlinear node detector transmits a fundamental wave signal into the detection area through a transmitting antenna and receives harmonic signals through second and third harmonic receiving antennas. It can then determine whether there are electronic devices containing nonlinear nodes within the detection area based on the harmonic signals. A shielding plate 23 is installed in the housing 21 of the nonlinear node detector, and this shielding plate 23 has electromagnetic shielding functionality. Therefore, when the nonlinear node detector is working, the second or third harmonic signals generated by the internal circuit unit 24 under the influence of the fundamental wave signal are weakened or blocked by the shielding plate 23, preventing leakage to the side of the shielding plate 23 where the antenna assembly 22 is located. This avoids the antenna assembly 22 receiving incorrect harmonic signals (harmonic signals generated by the circuit unit 24) leading to misjudgment, thus not affecting the detection accuracy of the detection equipment. This ensures the detection accuracy of the nonlinear node detector and reduces the false alarm rate.

[0096] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A detection device, characterized in that, include: Housing (21), antenna assembly (22), shielding plate (23) and circuit unit (24); The interior of the housing (21) has a receiving cavity; The antenna assembly (22), the shielding plate (23), and the circuit unit (24) are disposed in the receiving cavity, and one side of the shielding plate (23) is the antenna assembly (22), and the other side of the shielding plate (23) is the circuit unit (24). The shielding plate (23) is a component with electromagnetic shielding function.

2. The detection device according to claim 1, characterized in that, The shielding plate (23) is connected to or abuts against the inner wall of the receiving cavity, and divides the receiving cavity into a first chamber (213) and a second chamber (214). The antenna assembly (22) is located in the first chamber (213), and the circuit unit (24) is located in the second chamber (214).

3. The detection device according to claim 2, characterized in that, The detection device also includes a conductive element, which is located between the shielding plate (23) and the inner wall of the accommodating cavity, and is connected to the shielding plate (23) and the inner wall respectively. The conductive element has an electromagnetic shielding function.

4. The detection device according to claim 3, characterized in that, The conductive component is a conductive component formed by curing liquid conductive silver paste.

5. The detection device according to claim 3, characterized in that, The inner wall of the housing (21) is provided with conductive paint, and the conductive paint is connected to the conductive component.

6. The detection device according to claim 1, characterized in that, The shielding plate (23) is a metal plate.

7. The detection device according to any one of claims 1 to 6, characterized in that, The antenna assembly (22) includes: an antenna plate (221), a transmitting antenna, a harmonic receiving antenna, and a filter plate (222). The transmitting antenna and the harmonic receiving antenna are both mounted on the antenna plate (221). The filter plate (222) includes a substrate (2221) and a filter, wherein the substrate (2221) is located between the antenna plate (221) and the shielding plate (23); The filter is disposed on the side of the substrate (2221) away from the antenna plate (221), and the filter is connected to the harmonic receiving antenna and the circuit unit (24) respectively.

8. The detection device according to claim 7, characterized in that, The antenna assembly (22) further includes: a first shielding cover (223) which covers the filter; And / or, The detection device also includes a second shielding cover that covers at least a portion of the circuit unit (24).

9. The detection device according to claim 7, characterized in that, The circuit unit (24) is provided with an RF insertion terminal, and the filter is provided with an RF mating terminal that is detachably electrically connected to the RF insertion terminal; The shielding plate (23) has through holes for the RF insertion end or the RF mating end to pass through.

10. The detection device according to any one of claims 1 to 6, characterized in that, The detection device also includes: a display module (3), a flexible circuit board (4), and conductive foam; The display module (3) is electrically connected to the circuit unit (24) via a flexible circuit board (4); The conductive foam covers at least a portion of the flexible circuit board (4).

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