A multi-port test system and a fast time-sharing full cross S parameter measurement method

Abstract

A multi-port test system and a fast time-sharing full-cross S parameter measurement method belong to the field of electronic measurement and microwave radio frequency test, the excitation transmission path of the system includes an excitation source, an excitation switching module, M transmission routing amplification modules, and a double directional coupler matrix, the double directional coupler matrix has M groups, each group has N double directional couplers; M is greater than or equal to 2, and N is greater than or equal to 2; the reference receiving path includes the double directional coupler matrix, M reference routing amplification modules and M receiving modules; the measurement receiving path includes the double directional coupler matrix, M measurement routing amplification modules and the M receiving modules; two-way outputs of the receiving modules are digitized reference wave quantity data and measurement wave quantity data obtained through internal ADC sampling of the receiving modules; external test ports are divided into M groups, and each group includes N test ports. The method is carried out through the system to realize automatic test and performance characterization of multi-port microwave devices and components.

Description

Technical Field

[0001] This invention belongs to the field of electronic measurement and microwave RF testing technology, and is applied to the automated testing and performance characterization of multi-port microwave devices and components. Specifically, it relates to a multi-port testing system and a fast time-division fully cross S-parameter measurement method. Background Technology

[0002] Vector network analyzers are among the most commonly used instruments in the RF and microwave fields and in scientific research and production activities. They are mainly used to accurately measure the reflection and transmission characteristics of devices or networks. Currently, commercially available vector network analyzers are still predominantly two-port or four-port, mainly due to the needs of traditional testing scenarios and economic considerations. In recent years, with the continuous improvement of the performance indicators of complete equipment and the emergence of various high-performance multi-port components and complex modules, the comprehensive and rapid measurement of multi-port S-parameters has become a core requirement for characterizing the electrical characteristics of complex network systems.

[0003] In practical applications, the following are two typical requirements for comprehensive and rapid measurement of multi-port S-parameters:

[0004] 1) Radio Frequency Microwave Multiport Systems. Phased array radar, satellite communications, and 5G / 6G Massive MIMO systems widely employ array antennas containing multiple T / R components, multi-channel power combining and feeding networks, and MIMO (Multiple-Input Multiple-Output) radio frequency switch matrices. The overall performance of these systems directly depends on the amplitude and phase consistency, mutual coupling isolation, and transmission characteristics between dozens or even hundreds of ports. Therefore, complete full-crossing S-parameter measurements are essential to ensure the stability of beamforming, coherent reception, and signal routing. Any measurement omissions or errors can lead to system performance degradation or even failure.

[0005] 2) High-speed interconnect systems. With the rapid development of AI computing clusters and high-performance data centers, 400G, 800G, and even 1.6T high-speed interconnect technologies have become mainstream in the industry. High-speed copper cable components used for server and switch interconnects (such as PCIe 6.0 / 7.0, SAS-4, OSFP, QSFP-DDDAC cables, and ACC cables) need to undergo rigorous multi-port signal integrity testing, including differential insertion loss, return loss, near-end crosstalk, far-end crosstalk, and inter-port delay deviation. As line rates evolve from 56G PAM4 to 112G PAM4, 224G PAM4, and even 448G PAM4, the number of test channels and test complexity increase exponentially, expanding from 32 ports and 64 ports to 128 ports or even more, to meet the precise signal integrity and multi-channel consistency testing requirements of data centers, AI computing clusters, and next-generation high-speed interconnect systems. This also puts enormous pressure on testing efficiency and cost.

[0006] At the same time, multi-port devices or networks require precise and rapid testing and analysis of their S-parameter characteristics in all stages of research, development, production, installation, commissioning, and maintenance. These emerging demands make it difficult for traditional two-port or four-port vector network analyzers to meet the requirements by manually changing cables and making multiple connections. Not only is the testing efficiency low, but the poor repeatability of connections and the ease with which human error can be introduced also make them completely unable to meet the stringent requirements of modern R&D and production for high precision, high consistency, and full automation.

[0007] Against this backdrop, the industry generally adopts the following two mainstream multi-port extended testing solutions, but both have significant limitations:

[0008] 1) Vector Network Analyzer Cascaded with Mechanical Switch Box. This solution typically uses a two-port or four-port vector network analyzer as the host, and expands it through an external mechanical switch box. Its advantages lie in its simple circuit structure and control logic, and relatively low hardware investment. However, its drawbacks are also significant: First, mechanical switches have limited lifespan and slow switching speed, which is particularly pronounced in high-frequency and high-intensity testing scenarios; second, the mechanical switch box cannot add amplifiers to the test path to compensate for losses. As the operating frequency increases, the increased insertion loss not only reduces the system's dynamic range but also worsens the original directivity of the test ports by twice the effect of test path loss, severely sacrificing the system's measurement accuracy and stability; furthermore, the expanded test ports lack independent couplers and all reuse the native directional couplers of the vector network analyzer host. This prevents full cross-parameter measurements between test ports sharing the same directional coupler, and the number of calibrations and calibration time increase exponentially with the number of ports, resulting in extremely low testing efficiency.

[0009] 2) Native Multiport Vector Network Analyzer. A typical example of this solution is a multiport vector network analyzer based on a PXIe modular architecture, which expands the number of ports by integrating multiple transceiver modules. Its advantage lies in its ability to directly provide multiport testing capabilities and support full cross-sectional S-parameter measurements, resulting in high testing efficiency. However, its drawbacks are equally significant: First, the hardware cost is extremely high; the high unit price of each port causes the total cost to rise sharply with the increase in the number of ports, far exceeding the budget of typical R&D and production testing scenarios. Furthermore, as the number of modules increases, the system size and power consumption increase significantly, which is not conducive to deployment and use on large-scale production lines, resulting in low overall cost-effectiveness and difficulty in widespread adoption.

[0010] Therefore, exploring a new type of multi-port test system and measurement method that can ensure test accuracy and efficiency while significantly reducing system cost and complexity has become a key technical problem that the industry urgently needs to solve, and it is also an inevitable trend to promote the development of radio frequency microwave systems and high-speed interconnect technology. Summary of the Invention

[0011] This invention addresses the problems existing in the technical background by proposing a multi-port testing system and a rapid time-division fully cross S-parameter measurement method, aiming to overcome the limitations of the prior art and realize automated testing and performance characterization of multi-port microwave devices and components.

[0012] To achieve the above objectives, the present invention employs the following techniques:

[0013] A multi-port test system includes an excitation source, an excitation switching module, a local oscillator source, a local oscillator power divider module, a receiving module, a clock module, a transmit route amplification module, a reference route amplification module, a measurement route amplification module, and a dual directional coupler matrix.

[0014] The dual-directional coupler matrix consists of M groups of dual-directional couplers, each group having N dual-directional couplers; M≥2, N≥2.

[0015] The system's excitation transmission path consists of an excitation source, an excitation switching module, M transmit route amplification modules, and a dual directional coupler matrix. The input of the excitation source is connected to the system's clock module, and the output of the excitation source is connected to the input of the excitation switching module. The M outputs of the excitation switching module are connected to the single inputs of the M transmit route amplification modules. The N outputs of one transmit route amplification module are connected to the direct inputs of a group of N dual directional couplers in the dual directional coupler matrix. The direct outputs of the dual directional couplers serve as the system's external test ports.

[0016] The system's reference receiving path consists of the dual directional coupler matrix, M reference routing amplifier modules, and M receiving modules. The reference coupling outputs of the N dual directional couplers in one group of the dual directional coupler matrix are connected to the N inputs of one reference routing amplifier module. The single outputs of the M reference routing amplifier modules are connected to the reference inputs of the M receiving modules. The reference inputs are the radio frequency signals required by the reference mixer inside the receiving module.

[0017] The system's measurement receiving path consists of the dual directional coupler matrix, M measurement routing amplification modules, and M receiving modules in sequence. The measurement coupling outputs of the N dual directional couplers in one group of the dual directional coupler matrix are connected to the N inputs of one measurement routing amplification module, and the single outputs of the M measurement routing amplification modules are respectively connected to the measurement inputs of the M receiving modules. The measurement inputs are the radio frequency signals required by the measurement mixer inside the receiving modules.

[0018] The system's external test ports are divided into M groups, each containing N test ports. Each group corresponds to a set of dual directional couplers, a transmit route amplification module, a reference route amplification module, a measurement route amplification module, and a receive module.

[0019] The receiving module also includes a clock input, a local oscillator input, and two outputs. The two outputs are digital reference wave quantity data and measured wave quantity data obtained by the ADC inside the receiving module. The clock input of the receiving module is connected to the system's clock module.

[0020] The local oscillator signal path of the system consists of a local oscillator source, a local oscillator power divider module, and the M receiving modules in sequence. The input of the local oscillator source is connected to the clock module of the system, the output of the local oscillator source is connected to the local oscillator power divider module, and the M outputs of the local oscillator power divider module are respectively connected to the local oscillator inputs of the M receiving modules. The local oscillator inputs are the local oscillator signals required by the mixer inside the receiving modules.

[0021] Furthermore, the system also includes a communication control and signal processing module for centralized control and data processing;

[0022] The communication control and signal processing module connects to the excitation switching module, each transmit route amplification module, each reference route amplification module, each measurement route amplification module, and each receiving module. It is used to control the output switching of the excitation switching module, the time-division switching and status configuration of each route amplification module, and the time-division multiplexing of each receiving module.

[0023] The communication control and signal processing module is also connected to the excitation source, local oscillator source, and each receiving module. It is used to control frequency scanning and data acquisition, and to collect the reference wave quantity data and measured wave quantity data output by each receiving module for unified management and analysis.

[0024] The communication control and signal processing module has built-in multiple calibration algorithms to correct and compensate for error terms, thereby completing the automated calibration and measurement of the device under test.

[0025] A rapid time-division fully cross-validation S-parameter measurement method is implemented using the aforementioned multiport test system. Calibration steps:

[0026] S110, Single-port calibration:

[0027] Traverse all test ports of the system, and perform the following calibration operation on each test port as the target test port to obtain the single-port system error term of all test ports: route the excitation transmission path, reference reception path, and measurement reception path to the target test port, connect the target test port to various standard calibration devices, and obtain the reference wave quantity data and measurement wave quantity data of the corresponding receiving module when connecting various calibration devices, so as to solve the single-port system error term of the target test port;

[0028] S120, Unknown pass-through calibration of test ports in the same group:

[0029] S121. Test ports in the same group time-division multiplex the corresponding excitation transmission path, reference reception path, measurement reception path, and receiving module; select one test port as a common port, and connect any other test port in the same group as a direct connection port through a standard unknown through-calibrator.

[0030] S122. The excitation transmission path, reference reception path, and measurement reception path are all routed to the common port. The reference wave quantity data and reflection measurement wave quantity data of the receiving module at this time are obtained to obtain the forward reflection coefficient of the common port.

[0031] S123. Route the excitation transmission path and reference reception path to the common port, and route the measurement reception path to the direct connection port. Obtain the reference wave quantity data and transmission measurement wave quantity data of the receiving module at this time, so as to obtain the forward transmission coefficient from the common port to the direct connection port.

[0032] S124. The excitation transmission path, reference reception path, and measurement reception path are all routed to the direct connection port. The reference wave quantity data and reflection measurement wave quantity data of the receiving module at this time are obtained to obtain the reverse reflection coefficient of the direct connection port.

[0033] S125. The excitation transmission path and the reference reception path are routed to the direct connection port, and the measurement reception path is routed to the common port. The reference wave quantity data and the transmission measurement wave quantity data of the receiving module at this time are obtained, so as to obtain the reverse transmission coefficient from the direct connection port to the common port.

[0034] S126. Based on the forward reflection coefficient, forward transmission coefficient, reverse reflection coefficient, and reverse transmission coefficient obtained above, and combined with the single-port system error terms of the common port and the current directly connected port, the forward transmission tracking error term from the common port to the current directly connected port and the reverse transmission tracking error term from the current directly connected port to the common port are obtained.

[0035] S127. Keep the selected common port unchanged, traverse the remaining test ports in the same group as direct connection ports, and connect them to the unknown pass-through calibration component of the standard in turn with the selected common port to complete the unknown pass-through calibration of the test ports in the same group.

[0036] S130, Unknown pass-through calibration for different test ports:

[0037] S131. The excitation transmission path is time-division multiplexed for different groups of test ports. Each group of test ports corresponds to an independent reference receiving path, measurement receiving path and receiving module. The common port selected in step S120 is used as the common port for unknown direct calibration of different groups of test ports. Any test port of different groups is connected as a direct port through a standard unknown direct calibration component.

[0038] S132. The excitation transmission path is routed to the common port, the reference receiving path and measurement receiving path of the group to which the common port belongs are routed to the common port, and the reference receiving path and measurement receiving path of the group to which the directly connected port belongs are routed to the directly connected port; the reference wave quantity data, reflection measurement wave quantity data and transmission measurement wave quantity data of the receiving module corresponding to the common port and the receiving module corresponding to the directly connected port are obtained at this time, so as to obtain the forward reflection coefficient of the common port and the forward transmission coefficient from the common port to the directly connected port.

[0039] S133. The excitation transmission path is routed to the directly connected port, the reference receiving path and measurement receiving path of the group where the common port is located are routed to the common port, and the reference receiving path and measurement receiving path of the group where the directly connected port is located are routed to the directly connected port; the reference wave quantity data, reflection measurement wave quantity data of the receiving module corresponding to the directly connected port and the transmission measurement wave quantity data of the receiving module corresponding to the common port are obtained at this time, so as to obtain the reverse reflection coefficient of the directly connected port and the reverse transmission coefficient from the directly connected port to the common port;

[0040] S134. Based on the forward reflection coefficient, forward transmission coefficient, reverse reflection coefficient, and reverse transmission coefficient obtained in steps S132 and S133, and combined with the single-port system error terms of the selected common port and the current directly connected port, the forward transmission tracking error term from the common port to the current directly connected port and the reverse transmission tracking error term from the current directly connected port to the common port are solved.

[0041] S135. Keeping the selected common port unchanged, traverse all test ports in different groups from the common port as direct connection ports, and connect them to the unknown pass-through calibration component of the standard directly connected to the selected common port in turn to complete the unknown pass-through calibration of test ports in different groups.

[0042] S140. Perform unified analysis and management on the various error items obtained in steps S110, S120 and S130 to obtain all the systematic error items required to correct and compensate the test results of the test device, thereby achieving a comprehensive characterization of the characteristics of the test device.

[0043] Measurement steps:

[0044] S210, Test of reflection coefficient of a single port of the device under test:

[0045] Traverse all test ports connected to the device under test (DUT) and perform the following test operations on each test port connected to the DUT to obtain the reflection coefficient of all ports of the DUT: route the excitation transmission path, reference reception path, and measurement reception path to the test port connected to the target port of the DUT, and obtain the reference wave quantity data and reflection measurement wave quantity data of the receiving module corresponding to the test port at this time, thereby obtaining the reflection coefficient of the target port of the DUT;

[0046] S220, Transmission coefficient test between ports of the device under test:

[0047] If the test ports connected to the selected two test devices are in the same group, the test is performed according to the unknown pass-through calibration procedure of the same group test ports in step S120. When performing the test, the standard unknown pass-through component is replaced with the test device to measure the transmission coefficient between the two test device ports.

[0048] If the test ports connected to the two selected test devices are in different groups, the test is performed according to the unknown pass-through calibration steps of different groups of test ports in step S130. When performing the test, the standard unknown pass-through device is replaced with the test device to measure the transmission coefficient between the two test device ports.

[0049] S230, Combining the various error terms obtained in the calibration procedure:

[0050] By combining all the systematic error terms obtained in the calibration steps, the test results of the reflection coefficient obtained in step S210 and the transmission coefficient obtained in step S220 are corrected and compensated to achieve complete characteristic characterization of the device under test, that is, to complete the full cross S-parameter measurement of the device under test.

[0051] The beneficial effects of this invention are as follows:

[0052] 1) The multi-port test system described in this invention employs a transmit route amplification module for signal routing selection from one to many, a reference route amplification module for signal routing selection from many to one, and a measurement route amplification module. Routing is selected via internal solid-state electronic switches, avoiding contact wear issues present in mechanical switch boxes. This system offers advantages such as fast switching speed, no mechanical lifespan limitations, and high long-term stability, particularly in high-frequency and high-intensity testing scenarios. Furthermore, the system integrates source and receiver modules, enabling independent signal generation and reception processing without relying on external vector network analyzers. Additionally, it maximizes the reuse of transmit, reference, and measurement paths, as well as the receiver module, resulting in lower costs compared to PXIe, making it particularly suitable for large-scale production line deployments and automated testing requirements.

[0053] 2) The present invention proposes a fast time-division full-cross S-parameter measurement method, which fully utilizes the time-division switching mechanism of the routing module and the time-division multiplexing mechanism of the receiving module, and realizes full-cross S-parameter measurement support for the multi-port system. This overcomes the defect that full-cross S-parameter measurement cannot be performed between test ports that reuse the same directional coupler in a mechanical switch box. In addition, compared with traditional multi-port calibration test, this S-parameter measurement method significantly improves test efficiency while ensuring measurement accuracy. Attached Figure Description

[0054] Figure 1This is a block diagram of the multi-port test system structure when M=2 according to an embodiment of this application.

[0055] Figure 2 This is a block diagram of the multi-port test system structure when M=4 according to an embodiment of this application.

[0056] Figure 3 This is a description of the single-port system error model and its calibration schematic diagram according to an embodiment of this application.

[0057] Figure 4 This is a description of the two-port system error model and its calibration schematic diagram according to an embodiment of this application.

[0058] Figure 5 This is a description of the multi-port system error model and its calibration schematic diagram according to an embodiment of this application. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the implementation methods of the present invention will be described in detail below with reference to the accompanying drawings. However, the embodiments described in this invention are only some embodiments of the present invention, and not all embodiments.

[0060] This application provides a multi-port test system, including an excitation source, an excitation switching module, a local oscillator source, a local oscillator power divider module, a receiving module, a clock module, a transmit route amplification module, a reference route amplification module, a measurement route amplification module, a dual directional coupler matrix, a communication control and signal processing module, and a power supply module. The directional coupler matrix includes M groups of dual directional couplers, each group containing N dual directional couplers. Here, M≥2, N≥2. The total number of dual directional couplers is M*N, which is consistent with the number of external test ports of the system; that is, each external test port is equipped with an independent dual directional coupler.

[0061] The dual-directional coupler contains two coupling ports: a reference coupling port and a measurement coupling port. The coupling port closer to the excitation source is the reference coupling port, used to couple and capture the output signal of the excitation source; the coupling port closer to the system's external test port is the measurement coupling port, used to couple and capture the reflected or transmitted signal from the device under test.

[0062] The receiving module includes four inputs and two outputs. The four inputs are clock input, local oscillator input, reference input, and measurement input. The clock input is required for the sampling clock of the receiving module's internal ADC and is connected to the ADC sampling clock output of the clock module. The local oscillator input is required for the local oscillator signal of the receiving module's internal mixer and is connected to the output of the local oscillator power divider module. The reference input is required for the RF signal of the receiving module's internal reference mixer and is connected to the output of the reference routing amplifier module. The measurement input is required for the RF signal of the receiving module's internal measurement mixer and is connected to the output of the measurement routing amplifier module. The two outputs are the digitized reference waveform data and the measured waveform data obtained by the receiving module's internal ADC sampling, which are transmitted to the communication control and signal processing module for unified processing and analysis.

[0063] The clock module provides a unified reference signal and sampling clock: on the one hand, it outputs a highly stable RF reference signal to the excitation source and local oscillator source to ensure frequency and phase synchronization between signal sources; on the other hand, it distributes coherent ADC sampling clocks to multiple receiving modules to ensure data coherence and time synchronization between different channels, thereby avoiding phase drift and sampling deviation in multi-port measurements.

[0064] The local oscillator power module includes a single input and M outputs. The single input connects to the output of the local oscillator source, and the M outputs connect to the local oscillator inputs of M receiving modules respectively. The test ports of this multi-port test system are divided into M groups, each group containing N test ports, and each group corresponds to one receiving module. This means that if the test ports within a group need to acquire their respective reference, reflection, or transmitted wave quantity data, they all need to time-division multiplex the corresponding receiving modules.

[0065] like Figure 1 The diagram shows an example of the system structure when M=2. In this case, the excitation transmission path of the system consists of an excitation source, an excitation switching module, two transmit route amplification modules, and a dual-directional coupler matrix. The dual-directional coupler matrix includes two groups of dual-directional couplers, each group having N dual-directional couplers. The input of the excitation source is connected to the clock module of the system, and the output of the excitation source is connected to the input of the excitation switching module. The two outputs of the excitation switching module are respectively connected to the single inputs of the two transmit route amplification modules. The N outputs of one transmit route amplification module are connected to the direct inputs of the N dual-directional couplers in one group of the dual-directional coupler matrix. The direct outputs of the dual-directional couplers serve as the external test ports of the system.

[0066] The system's reference receiving path consists of the dual directional coupler matrix, two reference routing amplification modules, and two receiving modules. The reference coupling outputs of the N dual directional couplers in one group of the dual directional coupler matrix are connected to the N inputs of one reference routing amplification module, and the single outputs of the two reference routing amplification modules are connected to the reference inputs of the two receiving modules respectively.

[0067] The system's measurement receiving path consists of the dual directional coupler matrix, two measurement routing amplification modules, and the two receiving modules in sequence. The measurement coupling output terminals of the N dual directional couplers in one group of the dual directional coupler matrix are connected to the N inputs of one measurement routing amplification module, and the single outputs of the two measurement routing amplification modules are respectively connected to the measurement inputs of the two receiving modules.

[0068] The receiving module also includes a clock input, a local oscillator input, and two outputs. The two outputs are digital reference wave quantity data and measured wave quantity data obtained by the ADC inside the receiving module.

[0069] The system's external test ports are divided into two groups, each containing N test ports. Each group corresponds to a set of dual directional couplers, a transmit route amplification module, a reference route amplification module, a measurement route amplification module, and a receive module.

[0070] The local oscillator signal path of the system consists of a local oscillator source, a local oscillator power distribution module, and the two receiving modules in sequence. The input of the local oscillator source is connected to the clock module of the system, the output of the local oscillator source is connected to the local oscillator power distribution module, and the two outputs of the local oscillator power distribution module are respectively connected to the local oscillator inputs of the two receiving modules.

[0071] like Figure 2 The diagram shows an example of the system structure when M=4. In this case, the excitation transmission path of the system consists of an excitation source, an excitation switching module, four transmit route amplification modules, and a dual-directional coupler matrix. The dual-directional coupler matrix includes four groups of dual-directional couplers, each group having N dual-directional couplers. The input of the excitation source is connected to the clock module of the system, and the output of the excitation source is connected to the input of the excitation switching module. The four outputs of the excitation switching module are respectively connected to the single inputs of the four transmit route amplification modules. The N outputs of one transmit route amplification module are connected to the direct inputs of the N dual-directional couplers in one group of the dual-directional coupler matrix. The direct outputs of the dual-directional couplers serve as the external test ports of the system.

[0072] The system's reference receiving path consists of the dual directional coupler matrix, four reference routing amplification modules, and four receiving modules. The reference coupling outputs of the N dual directional couplers in one group of the dual directional coupler matrix are connected to the N inputs of one reference routing amplification module, and the single outputs of the four reference routing amplification modules are connected to the reference inputs of the four receiving modules.

[0073] The system's measurement receiving path consists of the dual directional coupler matrix, four measurement routing amplification modules, and the four receiving modules in sequence. The measurement coupling output terminals of the N dual directional couplers in one group of the dual directional coupler matrix are connected to the N inputs of one measurement routing amplification module, and the single outputs of the four measurement routing amplification modules are respectively connected to the measurement inputs of the four receiving modules.

[0074] The system's external test ports are divided into 4 groups, each containing N test ports. Each group corresponds to a set of dual directional couplers, a transmit route amplification module, a reference route amplification module, a measurement route amplification module, and a receive module.

[0075] The local oscillator signal path of the system consists of a local oscillator source, a local oscillator power distribution module, and the four receiving modules in sequence. The input of the local oscillator source is connected to the clock module of the system, the output of the local oscillator source is connected to the local oscillator power distribution module, and the four outputs of the local oscillator power distribution module are respectively connected to the local oscillator inputs of the four receiving modules.

[0076] Furthermore, based on the above concept, the path allocation and connection relationships are similar for other values ​​of M ≥ 2. The results are easily derived based on the cases of M=2 and M=4, and will not be elaborated here.

[0077] Specifically, the signal routing selection of the transmit routing amplifier module ranges from one to multiple, and the routing is achieved through the all-solid-state electronic switches used inside. The number of N outputs of a single transmit routing amplifier module can be two, three, four, five, six, seven, eight, etc., depending on the total number of test ports of the multi-port test system, specifically one-M of it, which matches the number of each set of dual directional couplers.

[0078] The signal routing selection of the reference routing amplifier module is from multiple to one, and the routing is achieved through the all-solid-state electronic switch used inside. The number of N inputs of a single reference routing amplifier module can be two, three, four, five, six, seven, eight, etc., and it is consistent with the number of N outputs of the transmit routing amplifier module.

[0079] The signal routing selection of the measurement routing amplifier module is reduced from multiple to one, and the routing is achieved through the all-solid-state electronic switch used inside. The number of N inputs of a single measurement routing amplifier module can be two, three, four, five, six, seven, eight, etc., and it is consistent with the number of N outputs of the transmitting routing amplifier module and the number of N inputs of the reference routing amplifier module.

[0080] In this example, the power supply module provides power to the system. The communication control and signal processing module is used for centralized control and data processing. It connects to the excitation switching module, each transmit route amplification module, each reference route amplification module, each measurement route amplification module, and each receiving module. It controls the output switching of the excitation switching module, the time-division switching and status configuration of each route amplification module, and the time-division multiplexing of each receiving module. The communication control and signal processing module also connects to the excitation source, local oscillator source, and each receiving module. It controls frequency scanning and data acquisition, and aggregates the reference wave quantity data and measurement wave quantity data output from each receiving module for unified management and analysis. The communication control and signal processing module has a built-in multi-calibration algorithm for correcting and compensating for error terms, thereby completing the automated calibration and measurement of the device under test. Through these functions, the communication control and signal processing module achieves centralized control of the testing process and comprehensive processing of measurement data within the system, ensuring the automation of the process and the accuracy of the results.

[0081] The multi-port test system described in this example is constructed through the coordinated use of an excitation transmit path, a reference receive path, a measurement receive path, a local oscillator path, and a clock path. Under the unified scheduling of the communication control and signal processing module, it provides complete hardware support for high-precision measurement of multi-port devices and networks. However, the system architecture alone is insufficient to meet the requirements for rapid and comprehensive multi-port characteristic characterization. If traditional multi-port calibration testing methods are used for full-cross S-parameter calibration and measurement, the testing efficiency will be extremely low. To address this, this application of the present invention also proposes a rapid time-division full-cross S-parameter measurement method based on the multi-port test system described in the preceding embodiments. This method achieves multi-port full-cross S-parameter calibration and measurement by time-division switching of switches within each routing module and time-division multiplexing of the receiving modules corresponding to the test ports within the group, thereby significantly improving testing efficiency while ensuring measurement accuracy.

[0082] For example Figure 2 The system architecture shown with M=4 serves as an example to illustrate the rapid time-division fully cross-connected S-parameter measurement method in detail. In this example, the number of external test ports is 32. The first group of test ports is numbered 1-8, the second group is numbered 9-16, the third group is numbered 17-24, and the fourth group is numbered 25-32. Each group corresponds to a dual directional coupler, a transmit route amplification module, a reference route amplification module, a measurement route amplification module, and a receive module.

[0083] Calibration steps:

[0084] S110, Single-port calibration:

[0085] The excitation transmission path, reference reception path, and measurement reception path are all routed to test port 1. Test port 1 is then connected to various standard calibration components, such as open circuits, short circuits, and matched loads, and reference waveform data of the corresponding receiving module is acquired when each calibration component is connected. and measured wave quantity data This is used to solve for the single-port system error term of the target test port.

[0086] Because there is a specific dependency between the measured and characterized values ​​of the reflection coefficient of the standard calibration piece and the test system, and the characterization of this dependency describes the single-port error model of the system, such as... Figure 3 The single-port system error model description and calibration diagram shown are illustrated, along with the standard calibration component ( Cal Kits The measured value of the reflection coefficient of ) and its characterization value With single-port system error term The dependencies between them satisfy the following equation:

[0087] (1)

[0088] In equation (1), j Ports are numbered 1, 2, ..., 32; standard calibration components are open circuit, short circuit, and matched load, respectively. Three dependency equations as shown in equation (1) are established to solve for the single-port system error term of test port 1, specifically the directional error. Source matching error Reflection tracking error .

[0089] Repeat the above steps to iterate through test ports 1 to 32, completing the single-port calibration for all test ports.

[0090] S120, Unknown pass-through calibration of test ports in the same group:

[0091] S121, The test ports in the same group are time-division multiplexed with the corresponding excitation transmission path, reference reception path, measurement reception path and receiving module; Test port 1 is selected as the common port, which is connected to test port 2 in the same group as a direct connection port through a standard unknown through-calibration component;

[0092] S122. Route the excitation transmission path, reference reception path, and measurement reception path to the common port, and obtain the reference wave quantity data of the corresponding receiving module at this time. and reflection measurement wave quantity data This is used to obtain the forward reflection coefficient of the common port. ;

[0093] S123. Route the excitation transmission path and reference reception path to the common port, and route the measurement reception path to the directly connected port to obtain the reference wave quantity data of the corresponding receiving module at this time. and transmission of measured wave quantity data This allows us to obtain the forward transmission coefficient from the common port to the directly connected port. ;

[0094] S124. Route the excitation transmission path, reference reception path, and measurement reception path to the directly connected port, and obtain the reference wave quantity data of the receiving module at this time. and reflection measurement wave quantity data This is used to obtain the reverse reflection coefficient of the direct-connect port. ;

[0095] S125. Route the excitation transmission path and reference reception path to the directly connected port, and then route the measurement reception path to the common port to obtain the reference wave quantity data of the receiving module at this time. and transmission of measured wave quantity data This allows us to obtain the reverse transmission coefficient from the directly connected port to the common port. ;

[0096] S126. Based on the forward reflection coefficient obtained above... Forward transmission coefficient Reverse reflection coefficient Reverse transmission coefficient Combined with the single-port system error term of the common port Single-port system error term of the currently directly connected port Solving for the forward transmission tracking error term from the common port to the current directly connected port yields the solution. And the reverse transmission tracking error term from the current direct-connect port to the common port. ;

[0097] S127. Keep the selected common port as test port 1 unchanged, traverse the remaining test ports 3 to 8 in the same group as direct connection ports, and connect them to the unknown pass-through calibration component of the standard directly connected to test port 1 in turn to complete the unknown pass-through calibration of the test ports in the same group.

[0098] like Figure 4 The diagram shows a description of a two-port system error model and its calibration schematic. The unknown through-calibrator ( UT Transmission matrix measurement values and its true value Single-port system error term with two test ports and The dependencies between them satisfy the following equation:

[0099] (2)

[0100] In equation (2), j and k The numbers representing the two test ports. For testing ports j To test port k The forward transmission tracking error term, The measured values ​​of the transmission matrix of the standard unknown through-type calibrator are compared with the measured values ​​of the scattering parameter matrix, i.e., the S-parameter matrix. There exists an equivalent transformation relation that satisfies the following equation:

[0101] (3)

[0102] In equation (3), For testing ports j Forward reflection coefficient, For testing ports j To test port k Forward transmission coefficient, For testing ports k Reverse reflection coefficient, For testing ports k To test port j The reverse transmission coefficient;

[0103] In equation (2), The true value of the transmission matrix of the standard unknown through-type calibrator is given, along with the true value of the scattering parameter matrix, i.e., the S-parameter matrix. There exists an equivalent transformation relation that satisfies the following equation:

[0104] (4)

[0105] Standard unknown through-calibrator components must meet a basic condition: reciprocity of transmission, i.e. This holds true for most two-port passive pass-through devices. Thus, the true value of the transfer matrix for an unknown pass-through calibrator... Taking the determinant, the following equation exists:

[0106] (5)

[0107] Then, taking the determinant of both sides of equation (2), we have the following equation:

[0108] (6)

[0109] Thus, the forward transmission tracking error can be solved. The reflection tracking errors of the two test ports and the transmission tracking errors between the two test ports satisfy the following equation:

[0110] (7)

[0111] Thus, the reverse transmission tracking error can also be solved. .

[0112] S130, Unknown pass-through calibration for different test ports:

[0113] S131. The excitation transmission path is time-division multiplexed for different groups of test ports. Each group of test ports corresponds to an independent reference receiving path, measurement receiving path and receiving module. The common port selected in step S120, i.e., test port 1 of the first group, continues to be used as the common port for unknown direct calibration of different groups of test ports. Any test port of different groups is connected through a standard unknown direct calibration component, such as test port 9 of the second group, as a direct connection port.

[0114] S132. Route the excitation transmission path to the common port, the reference reception path and measurement reception path of the group containing the common port to the common port, and the reference reception path and measurement reception path of the group containing the directly connected port to the directly connected port; obtain the reference wave quantity data of the receiving module corresponding to the common port at this time. Reflection measurement wave quantity data And the transmission measurement wave quantity data of the receiving module corresponding to the direct connection port. This is used to obtain the forward reflection coefficient of the common port. Forward transmission coefficient from common port to direct-connect port ;

[0115] S133. Route the excitation transmission path to the directly connected port, and route the reference receiving path and measurement receiving path of the group containing the common port to the common port, and route the reference receiving path and measurement receiving path of the group containing the directly connected port to the directly connected port; obtain the reference wave quantity data of the receiving module corresponding to the directly connected port at this time. Reflection measurement wave quantity data And the transmission measurement wave quantity data of the receiving module corresponding to the public port. This is used to obtain the reverse reflection coefficient of the direct-connect port. and the reverse transmission coefficient from the direct-connect port to the common port ;

[0116] S134. Based on the forward reflection coefficient obtained in steps S132 and S133 Forward transmission coefficient Reverse reflection coefficient Reverse transmission coefficient Combined with the selected public port Single-port system error term of the currently directly connected port Solving for the forward transmission tracking error term from the common port to the current directly connected port yields the solution. And the reverse transmission tracking error term from the current direct-connect port to the common port. ;

[0117] S135. Keeping the selected common port unchanged, traverse all test ports in different groups from the common port as direct connection ports, that is, traverse the remaining test ports 10~16 in the second group, all test ports 17~24 in the third group, and all test ports 25~32 in the fourth group, and connect them directly to the unknown pass-through calibration component of the standard in turn to complete the unknown pass-through calibration of test ports in different groups.

[0118] The description of the two-port system error model and its calibration diagram are as follows: Figure 4 As shown, the solution method is the same as that for the unknown through calibration in the same group, and will not be repeated here.

[0119] S140. The various error terms obtained in steps S110, S120 and S130 are uniformly analyzed and managed by the communication control and signal processing module to obtain all the system error terms required to correct and compensate the test results of the device under test, thereby realizing a comprehensive characterization of the characteristics of the device under test.

[0120] Multiport system error model description and calibration diagram as follows: Figure 5 As shown. Test port. j One-to-one connection to the port of the device under test j ( j =1,2,……,32). According to the definition of scattering parameters, the test port... j When stimulating, the port of the device under test j Incident wave measurement value , Measurement value of reflected wave and the true value of its incident wave quantity True value of reflected wave quantity With test port j Single-port system error term The following equation is satisfied between them:

[0121] (8)

[0122] By linearly expanding equation (8) and iterating through test ports 1 to 32 as excitations, the following equation can be obtained:

[0123] (9)

[0124] In equation (9), A m, B m , A , B The measured values ​​of the incident wave matrix, reflected wave matrix, true value of the incident wave matrix, and true value of the reflected wave matrix of the device under test are obtained by integrating the data when test ports 1 to 32 are excited sequentially. These are specifically represented as follows:

[0125] (10)

[0126] In equation (9), E 00 , E 01 , E 10 , E 11 The matrix represents the single-port system error terms for test ports 1 through 32, as shown below:

[0127] (11)

[0128] Furthermore, according to the definition of scattering parameters, the measured value of the incident wave matrix of the measured object... A m Measured values ​​of the reflected wave matrix of the test piece B m Measured values ​​of scattering parameter matrix of the test piece and the true value of the incident wave matrix of the test piece A The true value of the reflected wave matrix of the test component B The true value of the scattering parameter matrix of the test piece The following equation applies between them:

[0129] (12)

[0130] Combining equations (9) and (12), we can obtain the following equation:

[0131] (13)

[0132] In equation (13), I 32×32 It is a 32-order identity matrix. E 11 The source matching error matrix of the single-port system integrating test ports 1-32 is known. However, the true value of the scattering parameter matrix of the device under test needs to be determined. It is also necessary to know the intermediate process matrix. K Expanding the matrix K The equation can be obtained as follows:

[0133] (14)

[0134] In equation (14), the measured value of the scattering parameter matrix of the test object is... It can be obtained through testing and is known. The reflection tracking error for each test port can be obtained through single-port calibration and is known. These are the forward and reverse transmission tracking errors between the common test port 1 and other directly connected test ports 2-32, respectively. These errors are known and can be obtained through unknown pass-through calibration. However, the forward and reverse transmission tracking errors between test ports that did not undergo direct unknown pass-through calibration are... The answer is unknown and needs to be calculated based on the errors obtained from previous calibrations. Observe the test port. j To test port k Transmission tracking error Test port 1 to test port j Transmission tracking error Test port k Transmission tracking error to test port 1 And the reverse tracking error of test port 1 There is a certain dependency relationship between them, which specifically satisfies the following equation:

[0135] (15)

[0136] The test port can then be determined. j To test port k Transmission tracking error Thus, the true values ​​of the scattering parameter matrix of the tested component can be obtained. The generated intermediate process matrix K A complete representation is obtained, ultimately achieving a comprehensive characterization of the properties of the test piece.

[0137] The above calibration steps effectively correct and compensate for systematic error terms, ensuring the accuracy and consistency of measurement results. After calibration, the device under test (DUT) testing phase can begin. While ensuring error correction, a multi-port architecture and time-division multiplexing strategy can be used to achieve a complete characterization of the reflection and transmission characteristics between all ports of the DUT, i.e., full-crossing S-parameter measurement.

[0138] The basic assumptions of this embodiment remain unchanged, and each test port of the 32-port test system is connected to the 32-port device under test in a one-to-one correspondence.

[0139] Measurement steps:

[0140] S210, Test of reflection coefficient of a single port of the device under test:

[0141] The excitation transmission path, reference reception path, and measurement reception path are all routed to a test port connected to the target port of the device under test, such as test port 1, to obtain the reference waveform data of the corresponding receiving module at that test port. and reflection measurement wave quantity data This is used to obtain the reflection coefficient of the target port of the tested component. Repeat the above steps to iterate through all test ports connected to the system and the device under test (DUT) to obtain the reflection coefficients of all ports of the DUT. .

[0142] S220, Transmission coefficient test between ports of the device under test:

[0143] If the test ports connected to the two selected devices under test (DUTs) are in the same group, the test is performed according to the unknown pass-through calibration procedure for the same group test ports in step S120. During the test, the standard unknown pass-through device is replaced with the DUT to measure the transmission coefficient between the two DUT ports.

[0144]

[0145] when n When =1, test port j and test port k All belong to G 1. Corresponding to the first group of test ports 1~8, and the two are not the same test port, when n The same applies when taking other values, so I will not repeat them here.

[0146] If the test ports connected to the two selected devices under test are in different groups, the test is performed according to the unknown pass-through calibration procedure for different groups of test ports in step S130. During the test, the standard unknown pass-through device is replaced with the device under test to measure the transmission coefficient between the two device under test ports.

[0147]

[0148] That is when n When =1, test port j belong G 1. Corresponding to the first group of test ports 1~8, test ports k This belongs to all test ports 1~32 and G The difference set of 1, that is, the test ports remaining after removing the first group of test ports; when n The same applies when taking other values, so I will not repeat them here.

[0149] S230, Combining the various error terms obtained in the calibration procedure:

[0150] By combining all the systematic error terms obtained in the calibration steps, the test results of the reflection coefficient obtained in step S210 and the transmission coefficient obtained in step S220 are corrected and compensated to achieve complete characteristic characterization of the device under test, that is, to complete the full cross S-parameter measurement of the device under test.

[0151] The above description is only a preferred embodiment of this application and is not intended to limit this application. Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application.

Claims

1. A multi-port testing system, characterized in that: The system's excitation transmission path consists of an excitation source, an excitation switching module, M transmission route amplification modules, and a dual-directional coupler matrix. The dual-directional coupler matrix includes M groups of dual-directional couplers, each group containing N dual-directional couplers; M≥2, N≥2. The output of the excitation source is connected to the input of the excitation switching module. The M outputs of the excitation switching module are respectively connected to the single inputs of the M transmission route amplification modules. The N outputs of one transmission route amplification module are connected to the direct inputs of the N dual-directional couplers in one group of the dual-directional coupler matrix. The direct outputs of the dual-directional couplers serve as the system's external test ports. The system's reference receiving path consists of the dual directional coupler matrix, M reference route amplification modules, and M receiving modules, in that order. In a dual directional coupler matrix, the reference coupling outputs of N dual directional couplers in one group are connected to the N inputs of a reference routing amplifier module, and the single outputs of M reference routing amplifier modules are connected to the reference inputs of M receiving modules respectively. The system's measurement receiving path consists of the dual directional coupler matrix, M measurement routing amplification modules, and the M receiving modules in sequence. In a dual directional coupler matrix, the measurement coupling outputs of N dual directional couplers in one group are connected to the N inputs of a measurement routing amplification module, and the single outputs of M measurement routing amplification modules are connected to the measurement inputs of M receiving modules respectively. The receiving module also includes a clock input, a local oscillator input, and two outputs. The two outputs are digital reference wave quantity data and measured wave quantity data obtained by the ADC inside the receiving module. The system's external test ports are divided into M groups, each containing N test ports. Each group corresponds to a set of dual directional couplers, a transmit route amplification module, a reference route amplification module, a measurement route amplification module, and a receive module.

2. The multi-port testing system according to claim 1, characterized in that, The local oscillator signal path of the system consists of a local oscillator source, a local oscillator power divider module, and the M receiving modules in sequence. The input of the local oscillator source is connected to the clock module of the system, the output of the local oscillator source is connected to the local oscillator power divider module, and the M outputs of the local oscillator power divider module are respectively connected to the local oscillator inputs of the M receiving modules.

3. The multi-port testing system according to claim 2, characterized in that, The clock input of the receiving module is connected to the system's clock module, and the input of the excitation source is connected to the system's clock module.

4. The multi-port testing system according to claim 2, characterized in that, M=4, the total number of external test ports of the system is 4*N, divided into 4 groups, each group contains N test ports. The system has 4 groups of dual directional couplers, 4 transmit route amplification modules, 4 reference route amplification modules, 4 measurement route amplification modules, and 4 receive modules.

5. The multi-port testing system according to claim 2, characterized in that, The system also includes a communication control and signal processing module for centralized control and data processing; The communication control and signal processing module connects to the excitation switching module, each transmit route amplification module, each reference route amplification module, each measurement route amplification module, and each receiving module. It is used to control the output switching of the excitation switching module, the time-division switching and status configuration of each route amplification module, and the time-division multiplexing of each receiving module. The communication control and signal processing module is also connected to the excitation source, local oscillator, and each receiving module. It is used to control frequency scanning and data acquisition, and to collect the reference wave quantity data and measured wave quantity data output by each receiving module.

6. A fast time-sharing full-cross S-parameter measurement method, characterized in that, The method is implemented using the multi-port test system as described in any one of claims 1-5, and includes a calibration step: S110, Single-port calibration: Traverse all test ports of the system, and perform the following calibration operation on each test port as the target test port to obtain the single-port system error term of all test ports: route the excitation transmission path, reference reception path, and measurement reception path to the target test port, connect the target test port to various standard calibration devices, and obtain the reference wave quantity data and measurement wave quantity data of the corresponding receiving module when connecting various calibration devices, so as to solve the single-port system error term of the target test port; S120, Unknown pass-through calibration of test ports in the same group: S121. The test ports in the same group are time-division multiplexed with the corresponding excitation transmission path, reference reception path, measurement reception path and receiving module; one test port is selected as a common port and connected to any other test port in the same group as a direct connection port through a standard unknown through-calibrator. S122. The excitation transmission path, reference reception path, and measurement reception path are all routed to the common port. The reference wave quantity data and reflection measurement wave quantity data of the receiving module at this time are obtained to obtain the forward reflection coefficient of the common port. S123. Route the excitation transmission path and reference reception path to the common port, and route the measurement reception path to the direct connection port. Obtain the reference wave quantity data and transmission measurement wave quantity data of the receiving module at this time, so as to obtain the forward transmission coefficient from the common port to the direct connection port. S124. The excitation transmission path, reference reception path, and measurement reception path are all routed to the direct connection port. The reference wave quantity data and reflection measurement wave quantity data of the receiving module at this time are obtained to obtain the reverse reflection coefficient of the direct connection port. S125. The excitation transmission path and the reference reception path are routed to the direct connection port, and the measurement reception path is routed to the common port. The reference wave quantity data and the transmission measurement wave quantity data of the receiving module at this time are obtained, so as to obtain the reverse transmission coefficient from the direct connection port to the common port. S126. Based on the forward reflection coefficient, forward transmission coefficient, reverse reflection coefficient, and reverse transmission coefficient obtained above, and combined with the single-port system error terms of the common port and the current directly connected port, the forward transmission tracking error term from the common port to the current directly connected port and the reverse transmission tracking error term from the current directly connected port to the common port are obtained. S127. Keep the selected common port unchanged, traverse the remaining test ports in the same group as direct connection ports, and connect them to the unknown pass-through calibration component of the standard in turn with the selected common port to complete the unknown pass-through calibration of the test ports in the same group. S130, Unknown pass-through calibration for different test ports: S131. The excitation transmission path is time-division multiplexed for different groups of test ports. Each group of test ports corresponds to an independent reference receiving path, measurement receiving path and receiving module. The common port selected in step S120 is used as the common port for unknown direct calibration of different groups of test ports. Any test port of different groups is connected as a direct port through a standard unknown direct calibration component. S132. The excitation transmission path is routed to the common port, the reference receiving path and measurement receiving path of the group to which the common port belongs are routed to the common port, and the reference receiving path and measurement receiving path of the group to which the directly connected port belongs are routed to the directly connected port; the reference wave quantity data, reflection measurement wave quantity data and transmission measurement wave quantity data of the receiving module corresponding to the common port and the receiving module corresponding to the directly connected port are obtained at this time, so as to obtain the forward reflection coefficient of the common port and the forward transmission coefficient from the common port to the directly connected port. S133. The excitation transmission path is routed to the directly connected port, the reference receiving path and measurement receiving path of the group where the common port is located are routed to the common port, and the reference receiving path and measurement receiving path of the group where the directly connected port is located are routed to the directly connected port; the reference wave quantity data, reflection measurement wave quantity data of the receiving module corresponding to the directly connected port and the transmission measurement wave quantity data of the receiving module corresponding to the common port are obtained at this time, so as to obtain the reverse reflection coefficient of the directly connected port and the reverse transmission coefficient from the directly connected port to the common port; S134. Based on the forward reflection coefficient, forward transmission coefficient, reverse reflection coefficient, and reverse transmission coefficient obtained in steps S132 and S133, and combined with the single-port system error terms of the selected common port and the current directly connected port, the forward transmission tracking error term from the common port to the current directly connected port and the reverse transmission tracking error term from the current directly connected port to the common port are solved. S135. Keeping the selected common port unchanged, traverse all test ports in different groups from the common port as direct connection ports, and connect them to the unknown pass-through calibration component of the standard directly connected to the selected common port in turn to complete the unknown pass-through calibration of test ports in different groups. S140. Perform unified analysis and management on the various error items obtained in steps S110, S120 and S130 to obtain all the systematic error items required to correct and compensate the test results of the test device, thereby achieving a comprehensive characterization of the characteristics of the test device.

7. The rapid time-sharing full-cross S-parameter measurement method according to claim 6, characterized in that, During single-port calibration, the target test port is connected to three standard calibration components: an open circuit, a short circuit, and a matched load. The single-port system error includes directional error, source matching error, and reflection tracking error.

8. The rapid time-sharing full-cross S-parameter measurement method according to claim 7, characterized in that, The method includes measurement steps: S210, Test of reflection coefficient of a single port of the device under test: Traverse all test ports connected to the device under test (DUT) and perform the following test operations on each test port connected to the DUT to obtain the reflection coefficient of all ports of the DUT: route the excitation transmission path, reference reception path, and measurement reception path to the test port connected to the target port of the DUT, and obtain the reference wave quantity data and reflection measurement wave quantity data of the receiving module corresponding to the test port at this time, thereby obtaining the reflection coefficient of the target port of the DUT; S220, Transmission coefficient test between ports of the device under test: If the test ports connected to the selected two test devices are in the same group, the test is performed according to the unknown pass-through calibration procedure of the same group test ports in step S120. When performing the test, the standard unknown pass-through component is replaced with the test device to measure the transmission coefficient between the two test device ports. If the test ports connected to the selected two test ports are in different groups, the test is performed according to the unknown pass-through calibration steps for different groups of test ports in step S130. When performing the test, the standard unknown pass-through component is replaced with the test device to measure the transmission coefficient between the two test port ports. S230, Combining the various error terms obtained in the calibration procedure: By combining all the systematic error terms obtained in the calibration steps, the test results of the reflection coefficient obtained in step S210 and the transmission coefficient obtained in step S220 are corrected and compensated to achieve complete characteristic characterization of the device under test, that is, to complete the full cross S-parameter measurement of the device under test.

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