Circuit board assembly, radiation spurious emission anomaly detection method and electronic device

Abstract

The application discloses a circuit board assembly, a radiation spurious emission anomaly detection method and electronic equipment. The circuit board assembly comprises a main board, a signal detection circuit is arranged on the main board; a shielding cover is arranged above the main board and connected with the main board, a cavity is formed between the shielding cover and the main board; a support is arranged above the shielding cover and connected with the main board, a signal processing circuit is arranged on the support, the signal processing circuit is used for receiving a spurious signal leaked from the shielding cover, filtering and processing the spurious signal to obtain a harmonic signal, and transmitting the harmonic signal to the signal detection circuit; the signal detection circuit is used for receiving the harmonic signal, detecting the energy of the harmonic signal, and determining that the electronic equipment has a radiation spurious emission anomaly when the energy of the harmonic signal exceeds a threshold value. Through the arrangement of the signal processing circuit on the support and the signal detection circuit on the main board, whether the electronic equipment has a radiation spurious emission anomaly can be detected in real time.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of electronics, and particularly relates to a circuit board assembly, a radiated spurious emission anomaly detection method and an electronic device. BACKGROUND

[0002] Radio frequency interference is a pain point and a difficult problem in the mobile communication industry. Radio frequency interference generated by an electronic device may seriously affect the normal communication of other electronic devices. The authentication test item of radio frequency interference (EMC test) is one of the authentication test items that all manufacturers are most concerned about. Among them, the radiated spurious emission (RSE) is the most stringent and prone to problems.

[0003] During the production process of the electronic device, the manufacturer will test the RSE level of the electronic device. However, after the production of the electronic device is completed, the RSE anomaly of the electronic device may occur due to transportation, environmental humidity and other reasons. The manufacturer cannot detect the RSE level of the electronic device after the production of the electronic device is completed. SUMMARY

[0004] The present application aims to provide a circuit board assembly, a radiated spurious emission anomaly detection method and an electronic device to solve the problem that the RSE level of the electronic device cannot be detected after the production of the electronic device is completed.

[0005] In order to solve the above technical problems, the present application is implemented as follows:

[0006] In a first aspect, the present application embodiment provides a circuit board assembly, comprising:

[0007] a main board, wherein a signal detection circuit is arranged on the main board;

[0008] a shielding cover, which is arranged above the main board and connected with the main board, and a cavity is formed between the shielding cover and the main board;

[0009] a support, which is arranged above the shielding cover and connected with the main board, and a signal processing circuit is arranged on the support, wherein the signal processing circuit is used for receiving a spurious signal leaked from the shielding cover, performing filtering processing on the spurious signal to obtain a harmonic signal, and sending the harmonic signal to the signal detection circuit;

[0010] The signal detection circuit is used for receiving the harmonic signal, detecting the energy of the harmonic signal, and determining that the electronic device has a radiated spurious emission anomaly when the energy of the harmonic signal exceeds a threshold value.

[0011] Secondly, embodiments of this application propose a method for detecting abnormal radiated spurious emissions. The method is applied to the circuit board assembly described in the first aspect of this invention. The method includes: receiving spurious signals leaking from a shield; filtering the spurious signals to obtain harmonic signals; detecting the energy of the harmonic signals; and determining that the electronic device has an abnormal radiated spurious emissions when the energy of the harmonic signals exceeds a threshold.

[0012] Thirdly, embodiments of this application provide an electronic device including the circuit board assembly described in the first aspect of the present invention.

[0013] In the embodiments of this application, a bracket is set on the motherboard, and a signal processing circuit is provided on the bracket for receiving stray signals leaked from the shielding cover. The signal processing circuit can filter the stray signals to obtain harmonic signals and send the harmonic signals to the signal detection circuit on the motherboard. The signal detection circuit detects the energy of the received harmonic signals. When the energy of the harmonic signals exceeds a threshold, it determines that the electronic device has an abnormal radiated stray emission. After the electronic device is manufactured, it can also detect in real time whether the electronic device has an abnormal radiated stray emission.

[0014] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0015] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0016] Figure 1 This is a schematic diagram of a circuit board assembly according to an embodiment of the present invention;

[0017] Figure 2 This is a schematic diagram of another circuit board assembly in an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of the signal processing circuit in an embodiment of the present invention;

[0019] Figure 4 This is a schematic diagram of a microstrip bandpass filter in an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram of another circuit board assembly in an embodiment of the present invention.

[0021] Figure label:

[0022] 100 - main board; 101 - third microstrip antenna; 102 - transceiver; 200 - shield; 201 - opening; 300 - bracket; 301 - first microstrip antenna; 302 - microstrip bandpass filter; 303 - second microstrip antenna. DETAILED DESCRIPTION

[0023] Embodiments of the present application will be described in detail below with reference to examples thereof as illustrated in the accompanying drawings, in which like or similar elements and / or aspects with the same or similar functions and / or properties are designated by the same reference numerals throughout the drawings and the following detailed description. The embodiments described below with reference to the drawings merely exemplify the present application and are not to be interpreted in their restrictive sense. All other embodiments obtained by those skilled in the art based on the embodiments disclosed in the present application without creative efforts fall within the scope of the present application.

[0024] The terms "first", "second" in the specification and claims of the present application can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specified.

[0025] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0026] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] The following will be described in detail Figure 1 Figure 5 The circuit board assembly, the method for detecting abnormality of radiation spurious emission and the electronic device provided according to the embodiments of the present application are described.

[0028] According to an embodiment of the present application, a circuit board assembly is provided. As shown in Figure 1 ​As shown, the circuit board assembly comprises: a main board 100, wherein a signal detection circuit is arranged on the main board; a shielding cover 200, which is arranged above the main board 100 and connected with the main board 100, and a cavity is formed between the shielding cover 200 and the main board 100; and a support 300, which is arranged above the shielding cover 200 and connected with the main board 100, and a signal processing circuit is arranged on the support 300, wherein the signal processing circuit is used for receiving a stray signal leaked from the shielding cover 200, filtering the stray signal to obtain a harmonic signal, and sending the harmonic signal to the signal detection circuit. The signal detection circuit is used for receiving the harmonic signal, detecting the energy of the harmonic signal, and determining that the electronic device has an abnormal radiation stray emission when the energy of the harmonic signal exceeds a threshold value.

[0029] The support 300 can be clamped on the main board 100 through a buckle structure, or the support 300 can be fixed on the main board 100 through a screw, or other connection modes can be used between the support 300 and the main board 100, and the connection mode of the support and the main board is not limited in the embodiment. There can be a gap between the support 300 and the shielding cover 200, and there can also be a gap between the support 300 and the main board 100, and the size of the gap can be set according to actual needs.

[0030] The shielding cover 200 can be welded on the main board 100. In the case that the welding between the shielding cover 200 and the main board 100 is not firm, a stray signal will be leaked from the shielding cover 200. The signal processing circuit on the support 300 will receive the stray signal. The signal processing circuit filters the stray signal to obtain a harmonic signal. The signal processing circuit sends the harmonic signal to the signal detection circuit on the main board 100, and the energy of the harmonic signal is detected by the signal detection circuit on the main board 100. If the energy of the harmonic signal exceeds a threshold value, it means that the electronic device has an abnormal radiation stray emission. After detecting that the electronic device has an abnormal radiation stray emission, the detection result can be reported to the manufacturer of the electronic device, which is convenient for the manufacturer to recycle and reduce the number of defective products on the market.

[0031] According to the circuit board assembly of the embodiment of the application, the support is arranged on the main board, the signal processing circuit for receiving the stray signal leaked from the shielding cover is arranged on the support, the signal processing circuit can filter the stray signal to obtain a harmonic signal, and the harmonic signal is sent to the signal detection circuit on the main board. The signal detection circuit detects the energy of the received harmonic signal, and determines that the electronic device has an abnormal radiation stray emission when the energy of the harmonic signal exceeds a threshold value. The electronic device can also be detected in real time whether it has an abnormal radiation stray emission after being produced.

[0032] Optionally, as Figure 2As shown, the shielding cover 200 has an opening 201, and the signal processing circuit includes: a first microstrip antenna 301, disposed above the opening 201 of the shielding cover 200 or at the edge of the shielding cover 200, for receiving the spurious signal; a microstrip bandpass filter 302, the first end of which is connected to the first microstrip antenna 301, for filtering the fundamental frequency signal in the leaked signal and outputting a harmonic signal; and a second microstrip antenna 303, connected to the second end of the microstrip bandpass filter 302, for transmitting the harmonic signal to the signal detection circuit.

[0033] The shield 200 has an opening 201, and a first microstrip antenna 301 is disposed on the bracket 300 at a position opposite to the opening 201. Spurious signals will leak out from the opening 201 on the shield 200. By placing the first microstrip antenna 301 above the opening 201, it is easier for the first microstrip antenna 301 to receive spurious signals.

[0034] Spurious signals may also leak from the edge of the shield 200. The first microstrip antenna 301 can be positioned at the edge of the shield 200 to receive spurious signals leaking from this area. To ensure reception of spurious signals leaking from any location within the shield 200, the first microstrip antenna 301 can be positioned above the opening 201 of the shield 200 and at its edge.

[0035] like Figure 3 As shown, the first end of the microstrip bandpass filter 302 is connected to the first microstrip antenna 301 via a microstrip line. The second end of the microstrip bandpass filter 302 is connected to the second microstrip antenna 302 via a microstrip line. After the first microstrip antenna 301 receives a spurious signal, it transmits the spurious signal to the microstrip bandpass filter 302 via the microstrip line. The microstrip bandpass filter 302 filters the spurious signal to obtain a harmonic signal, which is then transmitted to the second microstrip antenna 303 via the microstrip line. The second microstrip antenna 303 sends the harmonic signal to the signal detection circuit on the motherboard 100.

[0036] In one example, such as Figure 3 As shown, the microstrip bandpass filter 302 is a 5th-order Chebyshev hairpin bandpass filter. The microstrip bandpass filter 302 includes five hairpin resonators, which are obtained by converting the half-wavelength stepped impedance resonator coupling structure into a U-shape. The performance of the microstrip bandpass filter 302 is determined by the structural parameters of each hairpin resonator. For example... Figure 4As shown, the arm length of the hairpin resonator is L, the spacing of the hairpin resonator is S, the line width of the hairpin resonator is W, and the tap position is t. By adjusting the structural size of the hairpin band-pass filter, the frequency response of the hairpin band-pass filter can be adjusted. The arm length L of the hairpin resonator is calculated as follows:

[0037]

[0038]

[0039] wherein h is the thickness of the dielectric plate of the microstrip structure, ε r is the relative dielectric constant of the dielectric, and λ0is the free space propagation wavelength at the center frequency point of the filter. The calculation formula of the tap position t is as follows:

[0040]

[0041] wherein R is the characteristic impedance of the tap line, Z0is the characteristic impedance of the hairpin resonator, and Q is the external coupling coefficient of the hairpin resonator.

[0042] The first microstrip antenna is arranged above the opening of the shield cover, so that the first microstrip antenna can more easily receive the spurious signals leaked from the opening of the shield cover, and the detection accuracy of the radiation spurious emission anomaly of the electronic device is improved.

[0043] Optionally, as Figure 5 shown, the signal detection circuit comprises: a third microstrip antenna 101 arranged on the mainboard 100 at a position opposite to the second microstrip antenna 303, the third microstrip antenna 101 being outside the shield cover 200 and used for receiving the harmonic signal sent by the second microstrip antenna 303. A transceiver 102 is connected with the third microstrip antenna 101 and used for detecting the energy of the harmonic signal, and when the energy of the harmonic signal exceeds a threshold value, it is determined that the electronic device has a radiation spurious emission anomaly.

[0044] The third microstrip antenna 101 and the transceiver 102 are arranged on the mainboard 100. The third microstrip antenna 101 is arranged on the mainboard 100 at a position opposite to the second microstrip antenna 303. Specifically, the third microstrip antenna 101 can be arranged below the second microstrip antenna 303. The transceiver 102 can be arranged at any position on the mainboard 100.

[0045] The third microstrip antenna 101 can receive harmonic signals transmitted by the second microstrip antenna 303. The third microstrip antenna 101 is connected to the transceiver 102 via a microstrip line. The third microstrip antenna 101 can transmit the received harmonic signals to the transceiver 102 via the microstrip line, and the transceiver 102 detects the energy of the harmonic signals. If the detected harmonic signal energy exceeds a threshold, it is determined that the electronic device has an abnormal radiated spurious emission.

[0046] In this embodiment, the third microstrip antenna is positioned on the motherboard opposite to the second microstrip antenna, which facilitates the third microstrip antenna in receiving the harmonic signals transmitted by the second microstrip antenna.

[0047] Optionally, such as Figure 5 As shown, the transceiver 102 is disposed in the cavity, and the transceiver 102 is connected to the third microstrip antenna 101 via a microstrip line.

[0048] The transceiver 102 is disposed within the cavity formed by the shielding cover 200 and the main board 100, and is located below the shielding cover 200. The transceiver 102 contains a receiver circuit that amplifies, mixes, filters, and detects harmonic signals to obtain frequency and energy information of the harmonic signals, thereby determining whether the electronic equipment exhibits abnormal radiated stray emissions.

[0049] When the transceiver is working, it generates radio frequency signals. In this embodiment, the transceiver is placed in the cavity formed by the shielding cover and the motherboard, which shields the radio frequency interference of the transceiver and allows the transceiver to work normally.

[0050] Optionally, the microstrip bandpass filter is any one of a hairpin bandpass filter, an interdigital bandpass filter, or a SIR (Stepped Impedance Resonators) parallel-coupled bandpass filter.

[0051] Optionally, the shielding cover 200 has a plurality of openings 201, and the first microstrip antenna 301 is provided on the bracket 300 at a position corresponding to each opening 201.

[0052] The shielding cover 200 may have multiple openings 201. When spurious leakage occurs, spurious signals can leak outward from the multiple openings 201 of the shielding cover 200. A first microstrip antenna 301 is provided on the support 300 at a position corresponding to each opening 201. The first microstrip antenna 301 can receive the spurious signals leaking from the corresponding opening 201. For example, if there are four openings 201 on the shielding cover 200, then there are four first microstrip antennas 301 on the support 300. Each first microstrip antenna 301 is connected to the first end of the microstrip bandpass filter.

[0053] This embodiment, by setting a first microstrip antenna corresponding to each opening when the shielding cover has multiple openings, can receive stray signals leaking from any opening, avoiding omissions and ensuring that all stray signals can be received, thereby improving detection accuracy.

[0054] Optionally, the first microstrip antenna 301 is disposed on the bracket 300 at a position corresponding to the edge of the shield 200.

[0055] Stray signals may also leak from the edge of the shield 200. The edge of the shield 200 refers to the connection point between the shield 200 and the motherboard 100. A first microstrip antenna 301 is provided at the edge of the shield 200. The first microstrip antenna 301 can receive stray signals leaking from the edge of the shield 200, further improving detection accuracy.

[0056] Optionally, the signal processing circuit can be implemented using any of the following methods: microstrip structure, laser-direct-structuring (LDS), liquid crystal polymer (LCP), or flexible printed circuit (FPC). Using a flexible printed circuit board allows the circuit board assembly to be bent freely, adapting to the internal space of the electronic device and improving the utilization of that space. An antenna can be formed on the circuit board assembly using laser-direct-structuring technology. The signal processing circuit can also be implemented using a liquid crystal polymer.

[0057] This embodiment introduces a method for detecting radiated stray emission anomalies. The method is applied to the circuit board assembly described in any embodiment of the present invention, and the method includes steps 101-104.

[0058] Step 101: Receive stray signals leaking from the shield.

[0059] The stray signals leaking from the shield are received by a first microstrip antenna on the support. These stray signals can leak from any opening in the shield or from the edge of the shield.

[0060] Step 102: Filter the stray signal to obtain the harmonic signal.

[0061] After receiving the spurious signal, the first microstrip antenna transmits the spurious signal to the microstrip bandpass filter. The microstrip bandpass filter filters the spurious signal, removing the fundamental frequency signal and obtaining the harmonic signal.

[0062] Step 103: detecting the energy of the harmonic signal.

[0063] After filtering the stray signal, the microstrip band-pass filter sends the harmonic signal to the second microstrip antenna. Under the joint action of the second microstrip antenna and the third microstrip antenna, the third microstrip antenna receives the harmonic signal. The third microstrip antenna sends the harmonic signal to the transceiver, and the energy of the harmonic signal is detected through the transceiver.

[0064] Step 104: determining that the electronic device has a radiation stray emission abnormality in a case where the energy of the harmonic signal exceeds a threshold value.

[0065] According to the detection result of the harmonic signal, it is judged whether the electronic device has a radiation stray emission abnormality. If the energy of the harmonic signal exceeds the threshold value, it is considered that the electronic device has a radiation stray emission abnormality.

[0066] The embodiment can detect in real time whether the electronic device has a radiation stray emission abnormality by receiving the stray signal leaked at the shielding cover, filtering the stray signal to obtain the harmonic signal, detecting the energy of the harmonic signal, and judging whether the electronic device has a radiation stray emission abnormality according to the detection result.

[0067] The embodiment introduces an electronic device having the circuit board assembly as described in any one of the above embodiments, which can detect in real time whether the electronic device has a radiation stray emission abnormality.

[0068] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0069] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A circuit board assembly, characterized in that, include: A motherboard, wherein a signal detection circuit is provided on the motherboard; A shielding cover is disposed above the motherboard and connected to the motherboard, and the shielding cover and the motherboard enclose a cavity to form a cavity; A bracket is disposed above the shield and connected to the motherboard. The bracket is provided with a signal processing circuit. The signal processing circuit is used to receive stray signals leaked from the shield, filter the stray signals to obtain harmonic signals, and send the harmonic signals to the signal detection circuit. The signal detection circuit is used to receive the harmonic signal, detect the energy of the harmonic signal, and determine that the electronic device has an abnormal radiated stray emission when the energy of the harmonic signal exceeds a threshold. The shielding cover has an opening, and the signal processing circuit includes: The first microstrip antenna is disposed above the opening of the shield or at the edge of the shield, and is used to receive the spurious signal; A microstrip bandpass filter, wherein the first end of the microstrip bandpass filter is connected to the first microstrip antenna, is used to filter out the fundamental frequency signal in the leaked spurious signal and output the harmonic signal; The second microstrip antenna is connected to the second end of the microstrip bandpass filter and is used to transmit the harmonic signal to the signal detection circuit. The signal detection circuit includes: The third microstrip antenna is disposed on the motherboard at a position opposite to the second microstrip antenna. The third microstrip antenna is located outside the shield and is used to receive the harmonic signal transmitted by the second microstrip antenna. A transceiver, connected to the third microstrip antenna, is used to detect the energy of the harmonic signal and determine that the electronic device has an abnormal radiated spurious emission when the energy of the harmonic signal exceeds a threshold.

2. The circuit board assembly according to claim 1, characterized in that, The transceiver is disposed within the cavity and is connected to the third microstrip antenna via a microstrip line.

3. The circuit board assembly according to claim 1, characterized in that, The microstrip bandpass filter can be any one of a hairpin bandpass filter, an interdigital bandpass filter, or a SIR parallel-coupled bandpass filter.

4. The circuit board assembly according to claim 1, characterized in that, The shield has multiple openings, and the first microstrip antenna is provided on the bracket at a position corresponding to each of the openings.

5. The circuit board assembly according to claim 1, characterized in that, The first microstrip antenna is positioned on the bracket at a location corresponding to the edge of the shield.

6. The circuit board assembly according to claim 1, characterized in that, The signal processing circuit can be implemented in any of the following ways: microstrip structure, laser direct forming technology, liquid crystal polymer, flexible circuit board.

7. A method for detecting radiated stray emission anomalies, characterized in that, The method for detecting radiated stray emission anomalies is applied to the circuit board assembly according to any one of claims 1-6, and the method includes: Receive stray signals leaking from the shielding cover; The stray signal is filtered to obtain the harmonic signal; Detect the energy of the harmonic signal; When the energy of the harmonic signal exceeds a threshold, it is determined that the electronic device has an abnormal radiated stray emission.

8. An electronic device, characterized in that, The circuit board assembly having any one of claims 1-6.

Images