Design And Research On SPDT RF MEMS Switch

In recent years , RF MEMS technology becomes more and more attractive in the communication field. Comparing with traditional semiconductor switch, it has the merit of low insertion loss, high isolation and good linearity. The market will definitely grow with further research of switch and improvement of switch lifetime.Four kinds of SP2T switches are designed in this paper, which are all based on parallel connection of clamped-end beam switch and series connection of cantilever beam switch. With the discussion and analysis of SP2T switch, the same principle can be applied to the design of switch arrays such as SPNT and DP2T switches.First,this paper analyzes the working principle of parallel connection switch and series connection switch. On the foundation of further studying and the assurance of characteristic impedance matched, two typical SP1T switches are designed. On the basis of the two SP1T switches, four SP2T switches are designed. The distance between two single switches and the structure of input port are the key consideration in designing. Two kinds of parallel connection SP2T switches are used in frequencies from 20 to 40 GHz. Series connection SP2T switch is used in frequencies from 0 to 20 GHz. One parallel connection switch and one series connection switch are separately connected on the two output ports of the last SP2T switch, which is highly valuable when the working frequencies of two output ports separately demand to be at low frequency and high frequency. Finally, Ansoft HFSS is used to analyze the RF performance of switches, and structures of switches are optimized under the premise of good RF performance of switches.