Research On Error Analysis And De-embedding Technology Of T/R Array Automatic Test System

T/R module is the foundation and core component of phased array radar.With the development of radar technology,T/R module presents the characteristics of multichannel,high frequency band and high performance.At the same time,it also puts forward new challenges to the test of T/R module.In order to solve the problem of T/R component test,the research and development of high performance T/R array automatic test system becomes more and more important.In order to achieve the purpose of automatic test,the T/R array test system will inevitably introduce complex embedded network such as connecting cable,transfer fixture and matrix switch,which seriously affects the de-embedding accuracy of the test system.In addition,when the test object of the system is multi-channel and multi-component,a large number of test channels need to be calibrated before measurement,which greatly reduces the cost of T/R array automatic test system The efficiency of de-embedding is improved.At present,the calibration method based on port extension is mainly used in engineering,such as SOLT calibration,and the embedded network is regarded as the system error elimination of vector network analyzer.Taking the test system as the object,using the traditional calibration scheme,the amplitude calibration absolute error is close to 0.2d B,the phase absolute error is greater than 3 ° and the standing wave ratio absolute error is greater than 0.15;secondly,the large-scale channel calibration of the system takes more than 90 minutes,and is prone to errors and repeatability errors.Aiming at the two key problems of T/R array automatic test system de-embedding accuracy and de-embedding efficiency,this paper studies the system de-embedding technology.Firstly,a system de-embedding scheme based on vector network self calibration and TRL standard embedded network parameter extraction is proposed.The TRL standard module and de-embedding algorithm are designed and implemented.The verification results of the test system show that the amplitude de-embedding absolute error is less than 0.11 d B,the phase absolute error is close to 2.2 ° and the VSWR absolute error is less than 0.10.In addition,multiple blind pull-out TRL components can be used at the same time to complete the de-embedding of multiple test channels.The deembedding time of the system can be compressed within 30 minutes.On this basis,in order to further improve the efficiency of de-embedding and realize the automatic online de-embedding function of the system,the online de-embedding technology based on USOM is studied.The designed USOM module and de-embedding algorithm are verified in the system.The results show that the amplitude de-embedding absolute error is less than 0.151 d B,the phase absolute error is close to 2.8 ° and the standing wave ratio absolute error is less than 0.122.In the later stage,the module can be integrated at the output end of the matrix switch,and the de-embedding can be completed automatically in the later stage.Then,in order to further reduce the dependence of the test system deembedding process on the standard parts and the requirements of the design accuracy of the calibration parts,a system de-embedding scheme based on genetic algorithm is proposed,which is only based on the through test data.The system verification results show that the amplitude de-embedding absolute error is less than 0.149 d B,the phase absolute error is close to 3.9 ° and the standing wave ratio absolute error is less than 0.156.Based on the research of test system de-embedding technology,this paper makes a comprehensive analysis of the uncertainty of the test system.The uncertainty of each component of the T/R array automatic test system is identified and calculated,and the evaluation result of the combined uncertainty of the test system is derived.