Conductive tape high frequency shielding coefficient test system and test method

Abstract

The present invention relates to a high-frequency shielding coefficient test system for a conductive tape, which comprises a test meter, a waveguide module, a test calibration piece and a test module; the test meter is used to test a test module connected to the waveguide module through a port when being debugged to a frequency band to be tested; the waveguide module is used to transmit electromagnetic waves from a single-conductor waveguide system to the test module and convert a dual-conductor waveguide system to a single-conductor waveguide system, and to connect to the test meter; the test calibration piece is used to calibrate the test end face of the waveguide module; the test module is used to connect to the waveguide module for testing after applying the conductive tape to be tested. The advantages of the present invention are: the structure is simple, stable testing is convenient, the data is stable and reliable, and the natural contact shielding coefficient of the conductive tape can be directly tested.

Description

Technical Field

[0001] The invention relates to the field of shielding coefficient testing of conductive materials, and in particular to a conductive tape shielding coefficient testing system and a testing method thereof. Background Art

[0002] In recent years, with the continuous advancement of electronic technology, electronic equipment has gradually developed in the direction of miniaturization, thinness and modularization. With the application of 5G communication technology, electronic equipment is increasingly developing in the direction of multi-band and broadband integrated applications. However, this development trend has undoubtedly greatly increased the difficulty of designing and manufacturing electronic equipment, and the mutual interference and compatibility of multiple frequency bands have also become the key difficulty in the integrated design of electronic equipment.

[0003] Due to the integrated design of the multifunctionality of electronic equipment, electronic equipment is gradually developing towards modularization. In the modular design of electronic equipment, the integration and isolation between modules are often shielded in their respective areas by means of shielding covers. However, with the high speed of data processing, the broadband of 5G communication, and the miniaturization of modules, the electromagnetic leakage problem between modules is becoming increasingly prominent. Therefore, the top of the module shielding cover, the main board, the area around the antenna, etc., are often pasted with conductive tape to reduce the interference electromagnetic waves of each frequency band leaked from the gaps of each module. This method is very dependent on the conductivity of the adhesive layer of the conductive tape. If the conductivity of the conductive tape adhesive layer is poor, the radiation of the module will exceed the standard. However, the traditional test method of conductive tape is to clamp the material tightly in a double-chamber test system to test the shielding performance of the material. This test method can test the shielding performance of the conductive tape in a relatively systematic way, but it is still different from actual use. In actual use, the conductive tape is applied to the surface of the object by viscosity, is in a free state, and is not affected by external forces, so the conductivity will decrease, and the shielding performance will naturally decrease, and the source of the decrease is mainly caused by the bonding of the conductive tape. Therefore, how to conveniently test the shielding coefficient of the conductive tape in a freely applied state and whether different materials can be distinguished and compared horizontally are issues that need to be considered at this stage. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a conductive tape high-frequency shielding coefficient testing system and testing method, which solves the shortcomings of the existing testing methods and can realize rapid testing of the shielding coefficient of the conductive tape.

[0005] The object of the present invention is achieved by the following technical scheme: a conductive tape high-frequency shielding coefficient test system, which includes a test instrument, a waveguide module, a test calibration piece and a test module;

[0006] The test instrument is used to test the test module connected to the waveguide module through the port when it is debugged to the frequency band to be tested;

[0007] The waveguide module is used to transmit electromagnetic waves from the single-conductor waveguide system to the test module and convert the dual-conductor waveguide system to the single-conductor waveguide system, and access the test instrument;

[0008] The test calibration piece is used to calibrate the test end face of the waveguide module;

[0009] The test module is used to attach the conductive tape to be tested and then connect it to the waveguide module for testing.

[0010] The waveguide module includes a standard rectangular waveguide and a waveguide-coaxial converter. The waveguide-coaxial converter is used to convert a dual-conductor waveguide system into a single-conductor waveguide system and connect to a dual-conductor port test instrument.

[0011] The test module includes an external flange structure and an inner conductor; the inner conductor has a sheet-like rectangular hollow structure to facilitate wave transmission, and a combing conductive structure is provided at the edge of the rectangular hollow structure to reduce the contact area between the conductive bottom and the metal. The conductive tape to be tested is cut into the size of the rectangular hollow structure and ensures that the application surface is tightly connected to the combing conductive structure.

[0012] The size of the inner conductor is the same as that of the standard rectangular waveguide, the thickness of the inner conductor is less than one tenth of the wavelength of the test center frequency, and the rectangular hollow structure is filled with a low dielectric constant material to ensure that the dielectric loss angle meets the requirements.

[0013] Conductive tape high frequency shielding coefficient test method, the test method comprising:

[0014] Calibration steps: Debug the test instrument to the frequency band to be tested, connect the waveguide module to the test instrument port to perform Through calibration in dual-port TRL or S-parameter mode, select the waveguide module port for calibration, and adjust the test curve to S-parameter test type after calibration.

[0015] Parameter test steps: Connect the test module with the conductive tape to be tested to the two ports of the waveguide module, read the S parameters at this time and subtract them from the S parameters during calibration to obtain the high-frequency shielding coefficient of the conductive tape.

[0016] The test module includes an external flange structure and an inner conductor; the inner conductor has a sheet-like rectangular hollow structure, and a combing conductive structure is provided at the edge of the rectangular hollow structure. The conductive tape to be tested is cut into the size of the rectangular hollow structure and ensures that the application surface is tightly connected to the combing conductive structure.

[0017] The test method also includes a test sample applying step; the test sample applying step includes: cutting the conductive tape to be tested into a size that is the same size as the rectangular hollow structure of the test module, applying it to any side of the rectangular hollow structure, and tightly connecting the applied surface with the combing conductive structure at the edge of the rectangular hollow structure.

[0018] The S parameter includes an S21 parameter or an S12 parameter.

[0019] The present invention has the following advantages: a conductive tape high-frequency shielding coefficient testing system and testing method, which has a simple structure and is convenient for stable testing, has stable and reliable data, and can directly test the natural contact shielding coefficient of the conductive tape. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the inner conductor structure of the test module Figure 1 ;

[0021] Figure 2 Schematic diagram of the inner conductor structure of the test module Figure 2 ;

[0022] Figure 3 Schematic diagram of connecting the test module to the waveguide module. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the detailed description of the embodiments of the present application provided below in conjunction with the drawings is not intended to limit the scope of protection of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. The present invention is further described below in conjunction with the drawings.

[0024] The present invention provides a conductive tape shielding coefficient test system and test method, the test frequency covers the frequency band of 400MHz to 60GHz; by applying the test to the material to be tested, the shielding characteristics of the applied conductive tape in the natural contact state are tested. In addition, the test system and test method are simple and reliable, and can compare material properties horizontally, greatly improving the test efficiency. It provides an effective method for material selection and identification. Specifically, it includes the following contents:

[0025] Test instrument: The test instrument is a standard vector network analyzer. The vector network analyzer has a single-port test function and can dynamically analyze the S parameters and impedance parameters of the port.

[0026] Waveguide module: The waveguide module consists of a standard rectangular waveguide and a waveguide-coaxial converter. The waveguide module is responsible for transmitting electromagnetic waves from a single-conductor waveguide system to the test module. The waveguide-coaxial converter is responsible for converting a dual-conductor waveguide system to a single-conductor waveguide system and connecting to a dual-conductor port test instrument.

[0027] Furthermore, the waveguide module is composed of a BJ18 standard rectangular waveguide and a BJ18 waveguide coaxial converter.

[0028] Test standard parts: Standard calibration parts are non-standard mechanical calibration parts, including short-circuit calibration flange and quarter-wavelength calibration flange.

[0029] Test module: The test module includes an outer flange and an inner conductor. The outer shape is a sheet-like rectangular hollow structure. The size of the inner conductor and the waveguide inner conductor is the same as that of the standard rectangular waveguide, and the thickness is less than one tenth of the wavelength of the test center frequency. The edge of the rectangular hollow structure has a combing conductive structure added inward. The hollow structure is filled with low dielectric resin (tetrafluoroethylene), the dielectric constant should be less than 2.1, and the dielectric loss angle should be less than one thousandth.

[0030] Furthermore, the appearance and structural dimensions of the test module are the same as those of the BJ18 waveguide and flange. The test module is 1mm thick, with an inner hollow structure of 129.54mm×64.77mm. The edges of the rectangular slots have a combing conductive structure added inwards, and the inner conductor structure without the flange is as follows Figure 1 As shown, the hollow area is filled with tetrafluoroethylene material, and after filling, the overall plane is kept smooth and parallel.

[0031] The specific test steps include:

[0032] Debug the test instrument to the frequency band to be tested, connect the waveguide module to the test instrument port, perform response (through) calibration on the system in dual-port TRL or S21 (S12) mode, select the waveguide module port for the calibration surface, and after calibration, adjust the test curve to the S21 (S12) parameter test type.

[0033] like Figure 2 As shown, the conductive tape to be tested is cut into the rectangular hollow size of the test module (129.54mm×64.77mm), and applied to the hollow structure in the test module, ensuring that the applied surface is tightly connected to the edge of the hollow structure of the test module, as shown in FIG. Figure 3 As shown, the test module is connected to the two ports of the waveguide module.

[0034] The S21 parameter is read as data, subtracted from the S21 data during calibration, and recorded as data to test the high-frequency shielding coefficient of the conductive tape.

[0035] The above is only a preferred embodiment of the present invention. It should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art shall not deviate from the spirit and scope of the present invention, and shall be within the scope of protection of the claims attached to the present invention.

Claims

1. Conductive tape high frequency shielding coefficient test system, characterized by: It includes a test instrument, a waveguide module, a test calibration piece and a test module; The test instrument is used to test the test module connected to the waveguide module through the port when it is debugged to the frequency band to be tested; The waveguide module is used to transmit electromagnetic waves from the single-conductor waveguide system to the test module and convert the dual-conductor waveguide system to the single-conductor waveguide system, and access the test instrument; The test calibration piece is used to calibrate the test end face of the waveguide module; The test module is used to attach the conductive tape to be tested and then connect it to the waveguide module for testing; The test module includes an external flange structure and an inner conductor. The inner conductor is in the shape of a sheet-like rectangular hollow structure to facilitate wave transmission. A comb-shaped conductive structure is provided at the edge of the rectangular hollow structure to reduce the contact area between the conductive tape and the metal. The conductive tape to be tested is cut into the size of the rectangular hollow structure and ensures that the application surface is tightly connected to the comb-shaped conductive structure.

2. The conductive tape high frequency shielding coefficient test system according to claim 1, characterized in that: The waveguide module includes a standard rectangular waveguide and a waveguide-coaxial converter. The waveguide-coaxial converter is used to convert a dual-conductor waveguide system into a single-conductor waveguide system and connect to a dual-conductor port test instrument.

3. The conductive tape high frequency shielding coefficient test system according to claim 2, characterized in that: The size of the inner conductor is the same as that of the standard rectangular waveguide, the thickness of the inner conductor is less than one tenth of the wavelength of the test center frequency, and the rectangular hollow structure is filled with a low dielectric constant material to ensure that the dielectric loss angle meets the requirements.

4. The test method of high frequency shielding coefficient of conductive tape is characterized by: The test method includes: Calibration steps: Debug the test instrument to the frequency band to be tested, connect the waveguide module to the test instrument port to perform Through calibration in dual-port TRL or S-parameter mode, select the waveguide module port for calibration, and adjust the test curve to S-parameter test type after calibration. Parameter test steps: Connect the test module with the conductive tape to be tested to the two ports of the waveguide module, read the S parameter at this time and subtract it from the S parameter during calibration to obtain the high-frequency shielding coefficient of the conductive tape; The waveguide module consists of a standard rectangular waveguide and a waveguide-coaxial converter. The waveguide module is responsible for transmitting electromagnetic waves from a single-conductor waveguide system to the test module. The waveguide-coaxial converter is responsible for converting a dual-conductor waveguide system to a single-conductor waveguide system and connecting to a dual-conductor port test instrument. The test module includes an external flange structure and an inner conductor; the inner conductor has a sheet-like rectangular hollow structure, and a comb-shaped conductive structure is provided at the edge of the rectangular hollow structure. The conductive tape to be tested is cut into the size of the rectangular hollow structure and ensures that the application surface is tightly connected to the comb-shaped conductive structure.

5. The method for testing the high-frequency shielding coefficient of a conductive tape according to claim 4, characterized in that: The test method also includes a test sample applying step; the test sample applying step includes: cutting the conductive tape to be tested into a size that is the same size as the rectangular hollow structure of the test module, applying it to any side of the rectangular hollow structure, and tightly connecting the applied surface to the comb-shaped conductive structure at the edge of the rectangular hollow structure.

6. The method for testing the high-frequency shielding coefficient of a conductive tape according to claim 4, characterized in that: The S parameter includes an S21 parameter or an S12 parameter.

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