Switch Based On Mems Technology And Ebg Tunable Filter Design

Developments in RF MEMS (Micro-Electro-Mechanical Systems) switches have demonstrated great potential for low-loss microwave application. MEMS shunt switches have advantages compared to the FET or PIN diode counterparts due to their characteristics of low intermodulation distortion or harmonics, low DC power consumption, low insertion losses and high isolation. Moreover, in the fast developing reconfigurable wideband and multi-band applications, the tunable filter is a critical element for frequency control in transceivers, multi-band communications and wideband radar systems. By integrating MEMS switches, MEMS-based tunable filter could achieve better performance.In this paper, the electrostatic actuated MEMS switch has been analyzed. The switch's mechanical and electromagnetic LRC models are demonstrated respectively. Based on the lumped model, the pull-in voltage formula of RF MEMS switch has been shown. With the help of commercial MEMS Finite Element Analysis software, MEMS switch's natural frequencies, modes and stress distribution are numerically calculated. In full-wave simulation, the electromagnetic response of the switch is analyzed.Based on standard MEMS process, MetalMUMPs, various thermal actuated MEMS lateral switches are designed and fabricated, such as SPDT switches, bi-stable switches, self-latch switches, polysilicon external heating switches and etc. Driven by joule heat, these switches require low actuation voltage and exhibit good performance due to the ohm contacts between thick metal layers. Self-latch switches also show good potential to lower power consumption for electro-thermal actuated MEMS switches.Electromagnetic Bandgap (EBG) structure is introduced in this paper. Through electromagnetic theory, the formula for calculating the EBG period is examined. Three different uniplanar EBG filters are designed and optimized by analyzing the electric and magnetic fields distributions, respectively. MEMS switches are incorporated in these EBG filters. MEMS and EBG based tunable filters have been obtained.