Study On Microwave Device Scattering Parameters In-Circuit Measurement Method

Microwave measurement technology has become a leader of the rapid development of microwave technology. Microwave network analysis is one of the most important research topics. The scattering parameters (S-parameters) which are one type network parameters have intuitively clear physical meaning and easy measurement, etc. Therefore, the measurement of the scattering parameters has been the basis of the measurement technique of microwave network. The conventional measurement methods can only measure the scattering parameters of separate device under test. We must adopt the in-circuit measurement methods to determine the performance of the microwave devices which are integrated together in circuit or microwave network.In this thesis, the scattering parameters measurement of the microwave devices with a two-port vector network analyzer are researched, propose specific solutions and experimental validation are given. This paper will be summed up, divided into the following sections:1) The microwave network theory which is related to the content of this paper is introduced. The characteristics of one-port, two-port and three-port network are discussed, and scattering parameters are derived. The traditional measurement methods of scattering parameters are discussed.:a two-port vector network analyzer structure, working principle and the calibration method.2) The in-circuit measurement method of the microwave devices scattering parameters is proposed. The specific in-circuit measurement steps of the one-port and two-port microwave devices are given. And the measurement value of the theoretical derivation. In addition, the scattering parameters in-circuit measurement methods in the case of known and unknown probe are analyzed.3) Scattering parameters in-circuit measurement methods are evaluated on the theory.4) In order to verify the correctness of the measurement methods and calibration method of in-circuit measurement of microwave devices, this paper carried out a large number of software simulation and experimental verification. The results which are analyzed from both simulation and in-circuit measurement show that the proposed in-circuit measurement method is feasible and calibration methods are correct and reliable. This paper puts forward the direction for further improvement work.