Key Technical Research On The Research On The Rf Mems Switch For Reconfigurable Frequency Selection Surfaces

Radio Frequency Micro-electro-mechanical system,Radio frequency Micro-electro-mechanical System,Therefore,RF MEMS can replace a new active mode named Reconfigurable Frequency Selective Surface(RFSS),and it has many advantages such as easy integration and small size.However,RF MEMS switches currently have the problems of high driving voltage and high insertion loss,which lead to the limited application range of RF MEMS switches.In addition,the application of RF MEMS switch in RFSS still has the problem that the MEMS switch bias network will affect the resonant structure of FSS.Therefore,the following contents are studied in this paper:1.To solve the problem of high switching driving voltage,a snakelike MEMS beam structure with low elastic coefficient is proposed in this paper,and its mechanical analysis model is constructed.The accuracy of the model is high,and the error between the model and the simulation data is only about 3%,which provides a theoretical basis for designing the beam structure with low driving voltage switch.In order to solve the problem that the capacitor extraction of RF MEMS switch is not accurate enough,the upstate capacitor extraction of RF MEMS switch is achieved by equivalent and quasi-static approximation of RF MEMS switch bridge through microstrip transmission line using the accurate solution method and precision compensation technology.2.In order to improve the RF performance of the switch,based on the transmission line theory,a new type of open resonant ring aperture structure etched on the transmission line of the switch is proposed in this paper,which can effectively improve the return loss of the switch.In order to solve the difficulty of establishing the equivalent circuit of RF MEMS switch,the inductance and resistance of the switch are calculated by extracting S parameter and resonant frequency,and then the switching electromagnetic and equivalent circuit models are established to complete the research of extracting the lumped parameters of the switch.3.A shunt capacitive RF MEMS switch with a new aperture structure is designed in this paper,and the theoretical analysis and simulation experiments of the switch are conducted in detail.The simulation test results show that the switch has excellent performance,its driving voltage is 6.5V,can operate in the frequency range of DC-60 GHz,has good isolation(less than-39 dB)at 30 GHz,has good insertion loss(-0.1 dB)and good return loss(-22.25 dB).4.In order to solve the problem that RF MEMS switch driving circuit affects the resonant surface of RFSS,a fusion design method of bias network and resonant element is proposed in this paper,and a RFSS based on RF MEMS switch is designed.Simulation test results show that the RFSS has the advantages of large bandwidth,high selectivity,good angular stability,etc.