Millimeter wave terahertz network parameter rapid test device and test method

Abstract

The invention discloses a millimeter wave terahertz network parameter rapid test device and test method, and belongs to the technical field of test. Coupling transmission between waveguide ports is achieved based on the non-contact waveguide connecting piece, high-quality signal transmission is guaranteed, meanwhile, a traditional screw fixing connection mode is eliminated, the influence of manual operation errors is effectively avoided, the testing stability and the testing precision are improved, and the service life of related devices of a testing instrument is prolonged; by adopting the rapid test connection device and the rapid calibration method, the test efficiency is greatly improved, the test experience is improved, and the rapid measurement requirement of the network parameters of the batch terahertz device can be met.

Description

Technical Field

[0001] The invention belongs to the field of testing technology, and in particular relates to a millimeter wave terahertz network parameter rapid testing device and a testing method. Background Art

[0002] The port network parameter test instrument of millimeter wave and terahertz devices has a high working frequency band. In order to reduce line loss, a dielectric-free metal waveguide is usually used as the transmission line. A vector network analyzer is used to connect the spread spectrum module to form a port network parameter test instrument. The port is a waveguide flange, which is tightly connected to the device under test by screws. The applicable frequency band generally includes 50GHz~1.5THz or even higher. Millimeter wave and terahertz vector network analyzers, spectrum analyzers, power meters and other test equipment all use the waveguide flange to tightly fix the connection method to measure the S parameters, output power, frequency conversion loss and other performance parameters of the device under test. Since the waveguide interface has high requirements for the flatness and tightness of the connection surface, and the tolerance standard increases with the increase of frequency, the connection between the test modules, the connection between the test module and the calibration device, and the connection between the test module and the device under test during the device test process all require manual operation to tightly screw and disassemble, and adjustment is required to ensure the alignment of the test instrument, which has a great impact on the test efficiency, test stability and test experience.

[0003] Disadvantage 1 of the existing technology: Human operation error affects the test accuracy;

[0004] The process of manually connecting the waveguide will introduce errors. The waveguide port is very small in the millimeter wave and terahertz frequency bands. The waveguide port requires a precise and stable connection, and has high requirements for the tightness and consistency of the connection fixation. It is difficult to control the consistency of the waveguide port connection by manual operation, and there may even be a situation where the connection is not tight and a small gap appears, which seriously affects the test accuracy. In order to solve this problem, the present invention adopts a connection method of waveguide coupling transmission, which avoids the influence of manual operation errors and can effectively improve the test stability and test accuracy.

[0005] The second disadvantage of existing technology: low testing efficiency and poor user experience;

[0006] Each calibration and test process of network parameter measurement based on waveguide transmission lines requires repeated removal of screws, which is time-consuming and has a poor user experience, and cannot meet the actual application requirements of large-scale rapid detection of devices. In view of this problem, the present invention designs a quick connection test device and working method, which greatly optimizes the calibration and test connection process, improves test efficiency, and enhances test experience.

[0007] The third disadvantage of the existing technology: the test instrument is subject to heavy wear and tear, which affects its service life;

[0008] Millimeter wave and terahertz test instruments are high-performance precision measuring instruments with high purchase and maintenance costs. Key waveguide structural parts are all high-flatness and smooth gold-plated surfaces. Repetitive mechanical stress will cause varying degrees of damage to them, increase maintenance costs, and affect service life. In response to this problem, the present invention designs a waveguide coupling transmission method based on non-contact connection to effectively protect the flatness and structural integrity of the contact surface.

[0009] The network parameter measurement of millimeter wave and terahertz devices has high requirements for connection precision due to the high operating frequency, short wavelength and electrical size limitation. The traditional test method uses screws to tightly fix the waveguide flange to achieve the connection of the waveguide transmission line. This connection method has the following defects: 1. It is difficult to accurately control the force of each screw due to manual operation errors, which makes it difficult for the waveguide flange to be perfectly flat and docked, directly affecting the test accuracy and test stability; 2. The connection process is cumbersome, which seriously affects the test experience and test efficiency; 3. Repeated tightening of the screws will inevitably cause damage to the waveguide port, affecting the durability of the test instrument.

[0010] In order to shorten the test time, improve the test efficiency, improve the test instability problem caused by manual operation errors, and meet the needs of high-stability and rapid batch detection of terahertz device network parameters, the present invention proposes a millimeter-wave terahertz network parameter rapid testing device and testing method, including a broadband waveguide coupling transmission structure, a multi-dimensional high-precision connection test fixture, a basic rapid interconnection network parameter test and calibration method, etc., to meet the industrial needs of rapid and batch detection of millimeter-wave and terahertz device network parameters. Summary of the invention

[0011] In view of the above technical problems existing in the prior art, the present invention proposes a millimeter wave terahertz network parameter rapid testing device and testing method, which are reasonably designed, overcome the shortcomings of the prior art, and have good effects.

[0012] In order to achieve the above object, the present invention adopts the following technical solution:

[0013] A millimeter wave terahertz network parameter rapid testing device comprises a vector network analyzer, a millimeter wave / terahertz spectrum expansion module, a spectrum expansion module fine adjustment base, a waveguide, a precision docking fixture, a non-contact waveguide connector, a one-dimensional / multi-dimensional slide rail test platform and a radio frequency cable; the millimeter wave / terahertz spectrum expansion module, the spectrum expansion module fine adjustment base, the waveguide, the precision docking fixture and the non-contact waveguide connector each have two, forming a set of symmetrical devices, and the symmetrical device is connected to the vector network analyzer to form a set of two-port network parameter testing devices;

[0014] The vector network analyzer is connected to the millimeter wave / terahertz spectrum expansion module through a radio frequency cable. The millimeter wave / terahertz spectrum expansion module is fixed to the one-dimensional / multi-dimensional slide rail test platform through the fine-adjustment base of the spectrum expansion module to achieve one-dimensional / multi-dimensional movement; the millimeter wave / terahertz spectrum expansion module is connected to the precision docking fixture through a waveguide and fixed with screws.

[0015] One end of the non-contact waveguide connector is fixed on a precision docking fixture, and the other end is a test port surface.

[0016] Preferably, the non-contact waveguide connector comprises a slotted waveguide, a positioning pin and a silicon-based non-contact connecting sheet;

[0017] The double-sided etching of the silicon-based non-contact connecting sheet has an artificial periodic electromagnetic bandgap structure, which is used to realize non-contact interconnection between the silicon-based non-contact connecting sheet and the waveguide, and between the silicon-based non-contact connecting sheet and the device to be tested;

[0018] The silicon-based non-contact connection sheet is fixedly assembled to the waveguide through the slotted waveguide and the positioning pins.

[0019] Preferably, the silicon-based non-contact connection sheet comprises an artificial periodic square column structure and a waveguide port conversion structure;

[0020] The artificial periodic square column structure is equivalent to an ideal magnetic surface, which can suppress electromagnetic leakage along the horizontal plane when connected to an ideal electric surface plane;

[0021] The waveguide port conversion structure is a three-step right-angle step. The non-uniform height conversion structure is designed near the waveguide port to avoid exciting the planar resonance mode and ensure the broadband characteristics of waveguide coupling transmission.

[0022] The waveguide port conversion structure is a stepped conversion structure, which improves the end matching of the surface wave of the artificial periodic square column structure, reduces the influence of surface wave reflection on the waveguide coupling transmission, and improves the stability of the waveguide coupling transmission.

[0023] In addition, the present invention also mentions a millimeter wave terahertz network parameter rapid testing method, which adopts the millimeter wave terahertz network parameter rapid testing device described above, and specifically includes the following steps:

[0024] Step 1: Install and connect the vector network analyzer, spread spectrum module, fine-tuning base, precision docking fixture, non-contact waveguide connector, one-dimensional / multi-dimensional slide rail test platform, configure parameters and preheat;

[0025] Step 2: Adjust the fine-tuning base of the spectrum expansion module to align the waveguide test port surfaces, and control the one-dimensional / multi-dimensional slide rails to make the waveguide test port surfaces slide smoothly without resistance when they are connected, and the adjustment is completed;

[0026] Step 3: Add a precision docking fixture between the spectrum expansion module and the contactless waveguide connector, and use the moving slide bar of the precision docking fixture to ensure that the waveguide test port surface is aligned in one dimension, thereby reducing the adjustment difficulty of step 2;

[0027] Step 4: Complete the calibration using the matching calibration parts and calibration methods;

[0028] Step 5: Place the DUT between a pair of non-contact waveguide connectors, and connect the DUT to the test port surface of the test device by controlling the one-dimensional / multi-dimensional slide rail test platform. The test port surface is not fixed with screws, and the waveguide test port surface is fixed by the mechanical stress of the one-dimensional / multi-dimensional slide rail test platform.

[0029] Step 6: Read the test parameters and complete the DUT test;

[0030] Step 7: Replace the test piece and repeat steps 5-6 to achieve rapid batch testing of the test pieces.

[0031] Preferably, in step 4, the calibration method comprises the following steps:

[0032] Step 4.1: Based on the principle of PEC-PMC interconnection, select matching calibration components; ensure that all test port surfaces during the test are in the PEC-PMC connection form.

[0033] Step 4.2: Perform reflection calibration, matching calibration, reflection offset calibration of a single port and through calibration of two ports;

[0034] Step 4.3: Introduce the PEC-PMC coupling transmission error correction model and the PMC-λ / 4-chip-PMC error correction model;

[0035] Step 4.4: Error correction compensation;

[0036] Step 4.5: Calibration completed.

[0037] Beneficial technical effects brought by the present invention:

[0038] The present invention realizes coupled transmission between waveguide ports based on a non-contact waveguide connector, which ensures high-quality signal transmission while getting rid of the traditional screw-fixed connection method, effectively avoiding the influence of manual operation errors, improving test stability and test accuracy, and increasing the service life of related components of the test instrument; the present invention adopts a fast test connection device and a fast calibration method to greatly improve test efficiency, improve test experience, and can meet the needs of fast measurement of network parameters of batch terahertz devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is the principle block diagram;

[0040] Figure 2 It is a structural composition diagram;

[0041] Figure 3 is the calibration flow chart;

[0042] Figure 4 is a schematic diagram of a contactless waveguide connector;

[0043] Figure 5 It is a schematic diagram of a silicon-based non-contact connection sheet;

[0044] Figure 6 It is a structural diagram of a one-dimensional adjustment test device;

[0045] Figure 7 It is a structural diagram of the multi-dimensional adjustment test device;

[0046] Among them, 1- vector network analyzer; 2- millimeter wave / terahertz spectrum expansion module; 3- spectrum expansion module fine-adjustment base; 4- waveguide; 5- precision docking fixture; 6- non-contact waveguide connector; 7- one-dimensional / multi-dimensional slide rail test platform; 8- radio frequency cable; 9- slotted waveguide, 10- positioning pin; 11- silicon-based non-contact connector; 12- artificial periodic square column structure; 13- waveguide port conversion structure; 14- one-dimensional slide rail base; 15- conventional port DUT; 16- support base; 17- rotation angle adjustment device; 18- height adjustment device; 19- one-dimensional slide rail adjustment device; 20- unconventional port DUT. DETAILED DESCRIPTION

[0047] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0048] The millimeter wave terahertz network parameter rapid testing device proposed by the present invention is as follows Figure 1 As shown. The overall composition includes a vector network analyzer 1, a millimeter wave / terahertz spectrum expansion module 2, a spectrum expansion module fine-adjustment base 3, a non-contact waveguide connector 6, a precision docking fixture 5, a one-dimensional / multi-dimensional slide rail test platform 7, and matching calibration parts, a waveguide 4, a radio frequency cable 8, etc. The vector network analyzer 1 is connected to the millimeter wave / terahertz spectrum expansion module 2 through the radio frequency cable 8, the millimeter wave / terahertz spectrum expansion module 2 is fixed and installed on the one-dimensional / multi-dimensional slide rail test platform 7 by the spectrum expansion module fine-adjustment base 3, the port of the millimeter wave / terahertz spectrum expansion module 2 is fixed to one side of the precision docking fixture 5 through the waveguide 4, and the non-contact waveguide connector 6 is fixed to the other side of the precision docking fixture 5. Two sets of the above devices are symmetrically installed and connected to the vector network analyzer 1 to form a two-port network parameter test device. The non-contact waveguide connector 6 is positioned by the moving slide bar of the precision docking fixture 5 to align the waveguide ports, and a test area with adjustable size is formed by moving the slide bar. The device to be tested or the calibration piece is placed in the area for rapid calibration or rapid testing.

[0049] The basic structure is as follows Figure 2 As shown, a vector network analyzer 1 and a pair of millimeter wave / terahertz spread spectrum modules 2 are connected through a radio frequency cable 8 to form a two-port vector network test device, the millimeter wave / terahertz spread spectrum module 2 is connected to a precision docking fixture 5 through a waveguide 4, the millimeter wave / terahertz spread spectrum module 2 is fixed on the spread spectrum module fine-adjustment base 3 and installed on a one-dimensional / multi-dimensional slide rail test platform 7 to realize one-dimensional / multi-dimensional movement, one end of the non-contact waveguide connector 6 is fixed on the precision docking fixture 5, and the other end surface is a test port.

[0050] The overall working principle and test method are as follows:

[0051] The two-port vector network analyzer and the spread spectrum module ports are connected to the non-contact waveguide connector to achieve screw-free fast interconnection. Only the waveguide port needs to be aligned without tight fixation, which greatly simplifies the accuracy requirements of the waveguide port connection and improves the test efficiency and stability. Non-contact waveguide connectors and matching calibration parts are designed. The connection with the spread spectrum module and the device under test is a waveguide coupling interconnection, so that the entire calibration and test process does not require screw fixation, and the test and calibration process time is greatly shortened.

[0052] The calibration method flow is as follows Figure 3 As shown in the figure, based on the standard two-port network parameter test calibration method, the equivalent ideal electric surface-ideal magnetic surface (PEC-PMC) signal transmission model of waveguide coupling transmission is established and introduced into the calibration model for compensation correction. In order to make all waveguide contact surfaces meet the equivalent PEC-PMC form, the through calibration uses a λ / 4 offset plate combined with a PMC-λ / 4 plate-PMC error correction model instead, and the matching calibration component terminal surface can choose PEC or PMC structure according to the connection requirements.

[0053] During the test, the one-dimensional or multi-dimensional sliding test platform is controlled to control the quick connection between the test piece and the test device. The normals passing through the center of the waveguide test port surface coincide with each other through connecting devices such as pins and sliding rods. No screw fixation is required, and only the sliding test device can ensure high-quality signal transmission at the connection of the test port surface. The test piece is replaced and the above test process is repeated to achieve rapid batch detection of devices.

[0054] The design of the key components, non-contact waveguide connector 6 and one-dimensional / multi-dimensional slide rail test platform 7, is introduced below.

[0055] The design of the non-contact waveguide connector 6 is as follows: Figure 4 As shown, the non-contact waveguide connector 6 includes a slotted waveguide 9, a positioning pin 10 and a silicon-based non-contact connector 11. The surface structure of the silicon-based non-contact connector 11 is as shown in FIG. Figure 5 As shown, it includes an artificial periodic square column structure 12 and a waveguide port conversion structure 13.

[0056] The working principle of the silicon-based non-contact connecting sheet 11 is as follows:

[0057] An artificial periodic structure equivalent to PMC is designed near the waveguide mouth, which can suppress electromagnetic leakage along the horizontal plane when connected to the PEC plane; the waveguide mouth conversion structure 13 is a right-angle three-step design, and a non-uniform height plane design is adopted near the waveguide mouth to avoid exciting the planar resonance mode, thereby ensuring the wide-band characteristics of the waveguide coupled transmission; the stepped conversion structure improves the end matching of the artificial periodic square cylinder surface wave, reduces the influence of surface wave reflection on the waveguide coupled transmission, and improves the stability of the coupled transmission.

[0058] The microstructure surface is formed based on silicon-based etching technology, and the silicon-based non-contact connecting sheet 11 is fixedly assembled on the metal waveguide using the slotted waveguide 9 and the positioning pins 10 to ensure the non-contact connection of the waveguide, and the processing accuracy is high, the structural strength is large, and the durability is strong.

[0059] The one-dimensional / multi-dimensional adjustment alignment connection device includes two design schemes: the one-dimensional adjustment test device is used to meet the connection of conventional interface DUTs, and the multi-dimensional adjustment test device is used to meet the connection of unconventional interface DUTs. Conventional port DUTs are similar to straight waveguides, with input and output ports on the same straight line and flush. The connection device only needs one-dimensional adjustment, such as Figure 6 As shown, the components include a millimeter wave / terahertz spectrum expansion module 2, a spectrum expansion module fine adjustment base 3, a waveguide 4, a precision docking fixture 5, a non-contact waveguide connector 6, and a one-dimensional slide rail base 14 and a conventional port DUT 15. The relative positions of the spectrum expansion module fine adjustment base 3 and the one-dimensional slide rail base 14 are controlled to achieve one-dimensional adjustment, and 5 is used to assist in further improving the waveguide port alignment accuracy. The input and output ports of the non-conventional port DUT may not be aligned in the horizontal, vertical, rotation angle and other directions, and a multi-dimensional adjustment connection device is required, such as Figure 7 As shown, it includes components of millimeter wave / terahertz spectrum expansion module 2, spectrum expansion module fine adjustment base 3, waveguide 4, precision docking fixture 5, non-contact waveguide connector 6, and support base 16, rotation angle adjustment device 17, height adjustment device 18, one-dimensional slide rail adjustment device 19, and unconventional port test piece 20, and controls each adjustment device to respectively realize the position adjustment of rotation angle, height, and horizontal direction. The one-dimensional adjustment test device is easy to debug, but it can only meet the rapid test of conventional port test pieces. The multi-dimensional adjustment test device is relatively complicated to debug, but it can meet the rapid test of unconventional port test pieces. The combination of the two test devices can meet the rapid test requirements of most millimeter wave terahertz devices.

[0060] The key points and protection points of the present invention are as follows:

[0061] (1) The present invention proposes a test device structure for rapid measurement of millimeter wave / terahertz device port network parameters, which is based on a waveguide non-contact coupling connection method and includes key components such as related connectors and precision adjustment and alignment devices, thus getting rid of the limitation of tight connection of waveguides.

[0062] (2) The present invention proposes a calibration method based on a fast interconnection test, using a fast interconnection matching calibration piece, and the entire calibration process is non-contact interconnection. An equivalent PEC-PMC signal transmission model is introduced and corrected on the basis of a standard two-port calibration method.

[0063] (3) The present invention proposes a broadband non-contact waveguide connector structure, which suppresses electromagnetic leakage in the gap of the connection surface based on the gap waveguide technology, designs a stepped transition structure to suppress the resonant mode, and improves the bandwidth and stability of the waveguide coupled transmission.

[0064] (4) The present invention proposes one-dimensional and multi-dimensional adjustment test devices for test pieces with different interface forms. The position of the test port is precisely adjusted by combining a slide rail base, a precision docking fixture, a rotation angle adjustment device, a height adjustment device, etc., to achieve high-precision and rapid connection between the test instrument and the test piece.

[0065] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A millimeter wave terahertz network parameter rapid testing device, characterized in that: It includes a vector network analyzer, a millimeter wave / terahertz spectrum expansion module, a fine-adjustment base for the spectrum expansion module, a waveguide, a precision docking fixture, a non-contact waveguide connector, a one-dimensional / multi-dimensional slide rail test platform, and a radio frequency cable; the millimeter wave / terahertz spectrum expansion module, the fine-adjustment base for the spectrum expansion module, the waveguide, the precision docking fixture, and the non-contact waveguide connector each have two, forming a set of symmetrical devices, and the symmetrical device is connected to the vector network analyzer to form a set of two-port network parameter test devices; The vector network analyzer is connected to the millimeter wave / terahertz spectrum expansion module through a radio frequency cable. The millimeter wave / terahertz spectrum expansion module is fixed to the one-dimensional / multi-dimensional slide rail test platform through the fine-adjustment base of the spectrum expansion module to achieve one-dimensional / multi-dimensional movement; the millimeter wave / terahertz spectrum expansion module is connected to the precision docking fixture through a waveguide and fixed with screws. One end of the non-contact waveguide connector is fixed on a precision docking fixture, and the other end is a test port surface.

2. The millimeter wave terahertz network parameter rapid testing device according to claim 1, characterized in that: A non-contact waveguide connector, comprising a slotted waveguide, a positioning pin and a silicon-based non-contact connector; The double-sided etching of the silicon-based non-contact connecting sheet has an artificial periodic electromagnetic bandgap structure, which is used to realize non-contact interconnection between the silicon-based non-contact connecting sheet and the waveguide, and between the silicon-based non-contact connecting sheet and the device to be tested; The silicon-based non-contact connection sheet is fixedly assembled to the waveguide through the slotted waveguide and the positioning pins.

3. The millimeter wave terahertz network parameter rapid testing device according to claim 2, characterized in that: Silicon-based non-contact connection sheet, including an artificial periodic square column structure and a waveguide port conversion structure; The artificial periodic square column structure is equivalent to an ideal magnetic surface, which can suppress electromagnetic leakage along the horizontal plane when connected to an ideal electric surface plane; The waveguide port conversion structure is a three-step right-angle step. The non-uniform height conversion structure is designed near the waveguide port to avoid exciting the planar resonance mode and ensure the broadband characteristics of waveguide coupling transmission. The waveguide port conversion structure is a stepped conversion structure, which improves the end matching of the surface wave of the artificial periodic square column structure, reduces the influence of surface wave reflection on the waveguide coupling transmission, and improves the stability of the waveguide coupling transmission.

4. A method for rapid testing of millimeter wave terahertz network parameters, characterized in that: The millimeter wave terahertz network parameter rapid testing device as claimed in claim 3 specifically comprises the following steps: Step 1: Install and connect the vector network analyzer, spread spectrum module, fine-tuning base, precision docking fixture, non-contact waveguide connector, one-dimensional / multi-dimensional slide rail test platform, configure parameters and preheat; Step 2: Adjust the fine-tuning base of the spectrum expansion module to align the waveguide test port surfaces, and control the one-dimensional / multi-dimensional slide rails to make the waveguide test port surfaces slide smoothly without resistance when they are connected, and the adjustment is completed; Step 3: Add a precision docking fixture between the spectrum expansion module and the contactless waveguide connector, and use the moving slide bar of the precision docking fixture to ensure that the waveguide test port surface is aligned in one dimension, thereby reducing the adjustment difficulty of step 2; Step 4: Complete the calibration using the matching calibration parts and calibration methods; Step 5: Place the DUT between a pair of non-contact waveguide connectors, and connect the DUT to the test port surface of the test device by controlling the one-dimensional / multi-dimensional slide rail test platform. The test port surface is not fixed with screws, and the waveguide test port surface is fixed by the mechanical stress of the one-dimensional / multi-dimensional slide rail test platform. Step 6: Read the test parameters and complete the DUT test; Step 7: Replace the test piece and repeat steps 5-6 to achieve rapid batch testing of the test pieces.

5. The working method of the millimeter wave terahertz network parameter rapid testing device according to claim 4 is characterized in that: In step 4, the calibration method includes the following steps: Step 4.1: Based on the principle of PEC-PMC interconnection, select matching calibration components; Step 4.2: Perform reflection calibration, matching calibration, reflection offset calibration of a single port and through calibration of two ports; Step 4.3: Introduce the PEC-PMC coupling transmission error correction model and the PMC-λ / 4-chip-PMC error correction model; Step 4.4: Error correction compensation; Step 4.5: Calibration completed.

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