Eqivalent Circuit Modeling And Performance Optimization Of Stripline RF Relay

Nowadays, with the development of communication business, the frequency of analogue and digital signals has been raised significantly. Moreover, as the microwave circuit is highly integrated, there is a pressing demand for radio frequency (RF) relay with better performance and integrating capability. RF relay controls the transmission and insulation of RF circuit, which makes it play an important role in determining the performance of the entire circuit. As one of the most integrating capable relay, strip-line RF relay is widely used in PCB mounted fields with its cost-efficiency. Therefore, it is of significant value to study on the fundamental theory and method of optimizing the performance of RF relay.In this paper, the theory of transmission line, the method of differential and statistics are employed to analyze the continuous and discontinuous structures of the signal path, based on which the equivalent circuit model of closed and open status of signal path are established. After the analysis and simulation of equivalent circuit, the effect of typical structures on RF performance, e.g. insertion loss, VSWR and isolation, is studied to confirm the influence factors for RF performance.In this paper, finite element method (FEM) was utilized to calculate the S parameters of signal path under the condition of impedance match of 50Ωand mode of TEM on the excitation terminal. Radiation loss is considered as well. The RF performance and the distribution of electromagnetic field were obtained. After that the relation between the variation of RF performance and the change of its factors was studied by which the appropriate range of the above factors for optimization is defined.In this paper, orthogonal experiment was utilized to optimize the design of signal path. With the consideration of actual production and assemblage process, constraint conditions of the parameters and the entire optimization function were defined. After the orthogonal experiment, the key factors of RF performance and the best levels of them were confirmed to optimize the RF performance.In this paper, the effect of techniques on RF performance is studied. Tolerance design was performed on the key factors of RF performance to reassign the tolerance of them and to simplify the process requirement. In addition, the effect of conducting and insulation materials on signal loss including conducting loss and insulation loss was studied.In this paper, the test method for PCB mounted relays were researched and test fixtures were designed. By comparing the difference between test results and FEM results, the validity of finite element model and equivalent circuit model was proved.