Automatic testing device for two-port passive filter

Abstract

The invention relates to an automatic testing device for a two-port passive filter, and the device comprises a testing cabinet which is internally provided with a multi-tone signal generation case, a frequency spectrograph, a vector network analyzer, an industrial control computer, a switch matrix, and a testing tool which is disposed outside the testing cabinet and is connected with the testing tool through a testing tool interface from top to bottom. The industrial personal computer is respectively connected with the multi-tone signal generation case, the frequency spectrograph, the vector network analyzer, the switch matrix and the test tool through an LAN and RS422, a test board card for installing a passive filter to be tested is placed in the test tool, the multi-tone signal generation case provides an input microwave signal for the test tool, the industrial personal computer issues a control instruction to the switch matrix, and the switch matrix is connected with the test board card. The switch matrix controls the frequency spectrograph and the vector network analyzer to measure the passive filter to be measured. According to the invention, generation of broadband microwave signals required by filter testing, channel switching of the microwave signals, data acquisition and storage of a testing instrument and related flow of report forming can be automatically and efficiently realized.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic component testing, and particularly to an automatic testing device for two-port passive filters. Background Art

[0002] Passive filters are widely used in electronic devices to filter out near-end interference signals in the passband of a frequency band, and are key components of electronic devices. They are mainly applied in systems such as navigation transceiver systems, channelized receivers, telemetry and remote control systems, front ends of phased array radar receivers, military communication systems, on-board seeker systems, and electronic countermeasures.

[0003] In recent years, due to the increasing demand for microwave instruments in the development of communication, radar electronics, and other cutting-edge technologies, such as microwave signal generators, microwave spectrum analyzers, microwave signal sources, and vector network analyzers. For the most common microwave components, namely passive filters, although modern test instruments introduce a large amount of computer technology to improve accuracy and functionality, the role of the automatic testing device for passive filters, which is the core part of the instrument, is irreplaceable. Currently, the mainstream passive filter testing devices have a relatively high level of testing accuracy, but there is still room for improvement in terms of integration, automation, and digitization.

[0004] Currently, in domestic passive filter testing, the following defects exist:

[0005] 1. The cables between multiple devices are complex, and frequent disassembly and assembly are required for environmental tests, resulting in low efficiency: Most use scattered instruments and meters (such as vector network analyzers, spectrum analyzers, signal generators, oscilloscopes, etc.), and there is no interconnection between these instruments and meters, and there is a lack of an industrial control computer and a main control program for unified control. Especially when multiple environmental tests need to be carried out on filters of the same batch (such as normal temperature testing, burn-in testing, high-temperature reverse bias testing, high-temperature testing, and low-temperature testing in sequence), the cables of these instruments and meters need to be disassembled and assembled before and after handling and then placed in the burn-in box or temperature chamber, which is time-consuming and laborious.

[0006] 2. Manual data recording is prone to errors and cannot meet the requirements of batch testing: It is necessary to manually read and record test data, which is prone to errors and time-consuming.

[0007] 3. Lack of a systematic control platform, making it difficult to achieve multi-parameter collaborative testing of multiple devices: When facing a large number of filter testing tasks, it is necessary to detect each device and each parameter one by one in a single-threaded manner, resulting in low efficiency.

[0008] In view of the above technical problems, an automatic testing device for two-port passive filters is proposed. Summary of the Invention

[0009] The object of the present invention is to overcome the deficiencies of the prior art and provide an automatic test device for two-port passive filters, which is used to carry out the electrical parameter test of two-port passive filters, verify the key parameters or application indicators of the current mainstream two-port passive filters, conduct functional and performance verification on these indicators, and determine whether the device under test meets the requirements of the device manual under variable conditions such as working mode, frequency, voltage, load, and environment in the actual use state, so as to determine whether the device under test meets the use requirements. It can be used to comprehensively consider the comprehensive performance indicators such as the functional performance, environmental adaptability, electromagnetic compatibility, reliability, and system compliance of the device under test, and can automatically and efficiently realize the generation of broadband microwave signals required for filter testing, the channel switching of microwave signals, the data acquisition and storage of test instruments, and the related processes of report formation.

[0010] The technical problems of the present invention are solved through the following technical solutions:

[0011] An automatic test device for two-port passive filters includes a test cabinet. Inside the test cabinet, a multi-tone signal generation chassis, a spectrum analyzer, a vector network analyzer, an industrial computer, a switch matrix are installed from top to bottom, and a test fixture connected through a test fixture interface is located outside the test cabinet. The industrial computer is connected to the multi-tone signal generation chassis, the spectrum analyzer, the vector network analyzer, the switch matrix and the test fixture respectively through LAN and RS422. The multi-tone signal generation chassis, the spectrum analyzer and the vector network analyzer are respectively connected to the switch matrix through RF connection lines. The switch matrix is connected to the test fixture through an RF connection line. A test board for installing the passive filter under test is placed inside the test fixture. The multi-tone signal generation chassis provides an input microwave signal for the test fixture. The industrial computer issues control instructions to the switch matrix, and the switch matrix controls the spectrum analyzer and the vector network analyzer to measure the passive filter under test.

[0012] Furthermore, it also includes a detachable front panel and rear panel located at the front end and rear end of the test cabinet. A switch and an indicator light are installed at the upper end of the front panel. The switch is the main switch during the test process, and the indicator light lights up when the test is in a normal communication connection state.

[0013] Furthermore, the front panel is provided with a network port and a serial port connector, which use aviation plugs; the rear panel is provided with a power supply interface.

[0014] Furthermore, it also includes a reserved expandable slot located at the lower end of the switch matrix.

[0015] Furthermore, it also includes a cable, a calibration component storage slot, a power supply and a socket located at the lower end inside the test cabinet.

[0016] Furthermore, it also includes a display located outside the test cabinet for displaying the test results.

[0017] Further, a radio frequency harness is connected to the front panel of the test tooling interface located at the upper end inside the test cabinet and connected to the test tooling, and power and control harnesses are placed on the rear panel of the test tooling interface.

[0018] Further, the industrial control computer includes hardware and software. The hardware includes a computer main board, a CPU, a memory, and a hard disk. The computer main board integrates a radio frequency switch matrix control board, a serial port, and a network port communication interface. The software is filter automatic test software.

[0019] Further, the switch matrix radio frequency switches of the switch matrix adopt 4 groups of single-pole eight-throw switches and 2 groups of single-pole double-throw switches.

[0020] The advantages and positive effects of the present invention are:

[0021] 1. The automatic test device for two-port passive filters of the present invention can fully cover the test items and verification indicators of typical two-port passive filters.

[0022] 2. The automatic test device for two-port passive filters of the present invention includes an industrial control computer for test control and test data processing and analysis of the entire device.

[0023] 3. The automatic test device for two-port passive filters of the present invention has the ability of automatic testing, can simultaneously test 16 two-port passive filters, and can realize functions such as test process control, automatic analysis and storage of test data, and automatic generation of test reports.

[0024] 4. The automatic test device for two-port passive filters of the present invention has standard SMA-K, RJ-45 network ports, and RS422 serial port type external interfaces and reserves a 19-inch standard slot, which is convenient for accessing expansion devices later.

[0025] 5. The automatic test device for two-port passive filters of the present invention realizes the functions of systematically controlling standard instruments and automatically obtaining test data of standard instruments through a radio frequency switch matrix module, a serial port, a network port communication control board configured in the industrial control computer, and filter automatic test software installed in the industrial control computer.

[0026] 6. The automatic test device for two-port passive filters of the present invention has a client access interface for the filter automatic test software, which is convenient for displaying test results and inputting test control through a monitor, a keyboard, and a mouse supporting the industrial control computer. Description of the Drawings

[0027] Figure 1 It is a schematic structural diagram of the automatic test device for two-port passive filters of the present invention;

[0028] Figure 2 This is the network communication interconnection relationship among the components of the automatic test device for the two-port passive filter of the present invention;

[0029] Figure 3 This is the radio frequency communication interconnection relationship of the automatic test device for the two-port passive filter of the present invention. Specific embodiments

[0030] The present invention will be further described in detail below through specific embodiments. The following embodiments are only descriptive and not restrictive, and the protection scope of the present invention cannot be limited thereby.

[0031] As Figure 1 shown, an automatic test device for a two-port passive filter includes a 19-inch standard test cabinet. Inside the test cabinet, a multi-tone signal generation chassis, a spectrum analyzer, a vector network analyzer, an industrial control computer, a switch matrix are installed from top to bottom, and a test fixture connected through a test fixture interface is located outside the test cabinet. The test fixture can freely disassemble and assemble test boards for two-port passive filters in different packaging forms to be compatible with filters in different packaging forms. The test board contains multiple test positions for placing the passive filter to be tested, and each test position has a set of input and output interfaces. A wall-mounted display is installed outside the test cabinet to display the test results. The industrial control computer is respectively connected to the multi-tone signal generation chassis, the spectrum analyzer, the vector network analyzer, the switch matrix and the test fixture through LAN and RS422. The multi-tone signal generation chassis, the spectrum analyzer and the vector network analyzer are respectively connected to the switch matrix through radio frequency connection lines. The switch matrix is connected to the test fixture through a radio frequency connection line. The test board for placing the passive filter to be tested is placed inside the test fixture. The multi-tone signal generation chassis provides an input microwave signal for the test fixture. The industrial control computer issues control instructions to the switch matrix, and the switch matrix controls the spectrum analyzer and the vector network analyzer to measure the passive filter to be tested.

[0032] All radio frequency interfaces of the test fixture, multi-tone signal generation chassis, spectrum analyzer, vector network analyzer, and switch matrix inside the test cabinet adopt SMA-type threaded fastening connectors to ensure the stability of the radio frequency connectors after the cabinet moves during the test.

[0033] Removable front and rear panels located at the front and rear of the test cabinet. The front panel is provided with an RJ-45 network port and a serial port connector, and aviation plugs are used to ensure the stability of the connectors after the test cabinet moves during the test; the rear panel is provided with a power interface.

[0034] There are switches and indicator lights installed at the upper end of the front panel. The switch is the main switch during the testing process, and each component has an independent power switch. During the testing process, the unused devices are turned off through the main switch to eliminate the electromagnetic interference and thermal effects of the components inside the test cabinet and improve the electrical performance stability. The indicator light lights up when the test is in a normal communication connection state to facilitate observing the actual test state.

[0035] The front panel of the test fixture interface located at the upper end inside the test cabinet and connected to the test fixture accesses the RF harness (high-frequency signal), and the rear panel of the test fixture interface places the power and control harness (low-frequency signal) to distinguish between high and low-frequency signals for easy interference isolation.

[0036] The industrial control computer uses a high-configuration controller as the software operation platform, which is modular and scalable. The industrial control computer motherboard integrates an RF switch matrix control board, serial ports, and network communication interfaces, facilitating the communication and interconnection of each functional unit of the test device. The industrial control computer panel is located directly in front of the test cabinet and is equipped with SMA-K, RJ-45 network ports, and RS422 serial port interfaces. The industrial control computer includes hardware and software. The hardware includes a computer motherboard, CPU, memory, and hard disk. The computer motherboard integrates an RF switch matrix control board, serial ports, and network communication interfaces. The software is the filter automatic test software.

[0037] The reserved expandable slot located at the lower end of the switch matrix can access expansion devices, facilitating subsequent maintenance and upgrade.

[0038] Cables, calibration component storage slots, power supplies, and power strips are located at the lower end inside the test cabinet.

[0039] The switch matrix RF switches of the switch matrix adopt 4 groups of single-pole eight-throw switches and 2 groups of single-pole double-throw switches.

[0040] Both the multi-tone signal generation chassis and the spectrum analyzer have a 50-ohm RF port impedance match. The two form an input-output loop and can also be used to measure the performance indicators of the passive filter under test.

[0041] In the present invention, a broadband microwave signal required for automatic testing is generated through the input port of the multi-tone signal generation chassis or the vector network analyzer and is input into the signal input end of the test fixture installed with the passive filter under test through the switching of the switch matrix microwave network. The corresponding test ports of the spectrum analyzer and the vector network analyzer are connected to the signal output end of the test fixture installed with the passive filter under test to form a test path. At the same time, the filter automatic test software establishes connections with the multi-tone signal generation chassis, the spectrum analyzer, and the vector network analyzer through the LAN and GPIB buses, sends command strings to control the instrument operation and data reading, and sends command strings to the switch matrix to implement path switching.

[0042] The present invention provides a standard voltage source, signal source, and working state simulation for the automated testing of two-port passive filters. It realizes the system integration of each tool module through a standard bus, forming an integrated testing device. The industrial control computer provides standard interfaces such as network ports, serial ports, and I / O ports externally for interconnection with the testing tooling, achieving signal acquisition and input, control of operation commands, and real-time monitoring of the testing state. At the same time, the industrial control computer can achieve system interconnection of the multi-tone signal generation chassis, spectrum analyzer, vector network analyzer, and switch matrix through the network port or GPIB interface, and construct a systematic testing platform through the filter automatic testing software to realize the customization of the testing process and the automation of the testing operation.

[0043] As Figure 2 shown, the network communication interconnection relationship and functions among the components of the present invention are as follows: The industrial control computer is interconnected with the switch matrix, vector network analyzer, multi-tone signal generation chassis, spectrum analyzer, and testing tooling through the connection methods of LAN and RS422 serial ports. The industrial control computer motherboard integrates a network switching module, power module, signal processing module, and control module, and realizes the control of all the other component parts through the filter automatic testing software, achieving the functions of issuing control instructions and transmitting test data back.

[0044] The switch matrix is connected to the industrial control computer through serial port and network port signals, and is used to control the switching between the RF paths connecting the testing tooling with the passive filter to be tested and the testing instruments. Specifically, the RF switches of the switch matrix adopt 4 groups of single-pole eight-throw switches and 2 groups of single-pole double-throw switches. The host computer software can switch 32 RF signals through the switch matrix and select the output of the corresponding 16 groups of signals. Therefore, the present invention can place 16 passive filters in the testing tooling at the same time, and through the path switching function of the switch matrix, test the 16 passive filters one by one for each path, greatly saving the time required for installing and disassembling the devices to be tested.

[0045] The testing tooling is used to place the passive filter to be tested; the vector network analyzer is used to measure the performance indicators of the passive filter to be tested; the multi-tone signal generation chassis provides input microwave signals for the testing tooling; the spectrum analyzer is used to measure the output signals of the multi-tone signal generation chassis.

[0046] The industrial control computer uses an RJ-45 network port to interconnect with the switch matrix, vector network analyzer, multi-tone signal generation chassis, spectrum analyzer, and testing tooling, and at the same time uses an RS422 interface to interconnect with the switch matrix as the input / output communication connection.

[0047] As Figure 3 shown, the RF communication interconnection relationship among the components of the present invention is as follows: The spectrum analyzer, multi-tone signal generation chassis, and vector network analyzer are connected to the switch matrix through RF connecting lines, and the switch matrix is connected to the testing tooling through RF connecting lines. The arrow direction in the figure is the RF signal transmission direction.

[0048] Use the automatic test device for two-port passive filters of the present invention to test two-port passive filters. Place the test board with the passive filter to be tested on the test fixture. Transmit the provided 50-ohm standard microwave signal to the input port of the passive filter to be tested. The operating frequency range of the switch matrix is 100 MHz to 18 GHz, which can cover the key test frequencies (100 MHz to 1 GHz) of the passive filter. The filter automatic test software issues control instructions through the industrial control computer. After receiving the issued instructions, the switch matrix performs corresponding switch switching actions to complete the control of the switch matrix. The test data is automatically saved in the hard disk of the industrial control computer and is analyzed and calculated through the filter automatic test software in the industrial control computer, and the test results are displayed on the display. The present invention can simultaneously perform automated tests on performance parameters such as the standing wave ratio, passband insertion loss, stopband rejection, and 3 dB cut-off frequency of multiple filters. The operation steps are as follows: Start the power supply, perform self-checks on the software and hardware, and calibrate the test link; Start the industrial control computer and the filter automatic test software; Place the test board with the passive filter to be tested on the test fixture; Input test parameters into the filter automatic test software through the keyboard and mouse configured by the industrial control computer and start the test; After the test is completed, replace a new batch of passive filters to be tested into the test fixture until all tests are completed; At the end of the test, read the test results in the filter automatic test software, display them on the display, and generate a test report. Use the industrial control computer to implement functions such as control of test instruments, control of test processes, automatic analysis and storage of test data, and automatic generation of test reports through the filter automatic test software installed in the industrial control computer.

[0049] It is used to carry out electrical parameter tests on two-port passive filters, verify the key parameters or application indicators of current mainstream two-port passive filters, and conduct functional and performance verification on these indicators. Whether the device under test meets the indicators in the device manual under variable conditions such as working mode, frequency, voltage, load, and environment in the actual use state, and determine whether the device under test meets the usage requirements. It can be used to comprehensively consider comprehensive performance indicators such as the functional performance, environmental adaptability, electromagnetic compatibility, reliability, and system compliance of the device under test, and can automatically and efficiently implement processes such as generation of broadband microwave signals required for filter testing, channel switching of microwave signals, data acquisition and storage of test instruments, and report formation.

[0050] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art can understand that various substitutions, changes, and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the content disclosed in the embodiments and drawings.

Claims

1. An automatic test device for a two-port passive filter, comprising a test cabinet, characterized in that: Inside the test cabinet, a multi-tone signal generation chassis, a spectrum analyzer, a vector network analyzer, an industrial computer, a switch matrix, and a test fixture connected through a test fixture interface outside the test cabinet are installed from top to bottom. The industrial computer is interconnected with the multi-tone signal generation chassis, the spectrum analyzer, the vector network analyzer, the switch matrix, and the test fixture through LAN and RS422 respectively. The multi-tone signal generation chassis, the spectrum analyzer, and the vector network analyzer are respectively connected to the switch matrix through RF connection cables. The switch matrix is connected to the test fixture through an RF connection cable. A test board for installing the passive filter under test is placed inside the test fixture. The multi-tone signal generation chassis provides an input microwave signal for the test fixture. The industrial computer issues control instructions to the switch matrix, and the switch matrix controls the spectrum analyzer and the vector network analyzer to measure the passive filter under test.

2. The automatic test device for two-port passive filters according to claim 1, characterized in that: It also includes a detachable front panel and a rear panel located at the front end and the rear end of the test cabinet. A switch and an indicator light are installed at the upper end of the front panel. The switch is the main switch during the test process, and the indicator light lights up when the test is in a normal communication connection state.

3. The automatic test device for two-port passive filters according to claim 1, characterized in that: The front panel is provided with a network port and a serial port connector, using aviation plugs; the rear panel is provided with a power interface.

4. The automatic test device for two-port passive filters according to claim 1, characterized in that: It also includes a reserved expandable slot located at the lower end of the switch matrix.

5. The automatic test device for two-port passive filters according to claim 1, characterized in that: It also includes cables, a calibration component storage slot, a power supply, and a power strip located at the lower end inside the test cabinet.

6. The automatic test device for two-port passive filters according to claim 1, characterized in that: It also includes a display located outside the test cabinet for displaying the test results.

7. The automatic test device for two-port passive filters according to claim 1, characterized in that: An RF harness is connected to the front panel of the test fixture interface that is connected to the test fixture at the upper end inside the test cabinet, and a power supply and a control harness are placed on the rear panel of the test fixture interface.

8. The automatic test device for two-port passive filters according to claim 1, characterized in that: The industrial computer includes hardware and software. The hardware includes a computer motherboard, a CPU, a memory, and a hard disk. The computer motherboard integrates an RF switch matrix control board, a serial port, and a network port communication interface. The software is an automatic filter test software.

9. The automatic test device for two-port passive filters according to claim 1, characterized in that: The switch matrix RF switch of the switch matrix uses 4 groups of single-pole eight-throw switches and 2 groups of single-pole double-throw switches.

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