Novel high capacitance ratio compact float metal based RF MEMS switch for multi band and variable bandwidth: design and RF performance analysis

Abstract

Modern complex systems, as they are multi functional, they require many small unit cells for multi functionality. These are certain applications, where the change in operational frequency band is required and switches designed for specific band is usually incorporated depending on requirement. The most complex task in radio-frequency RF microelectromechanical system (RF MEMS) switches is the designing of switches that are tuned for particular frequency band. To overcome these problems, we have proposed the design and modeling of multi band RF MEMS switch. The switch designed shows high capacitance ratio that is usually hard to achieve by conventional designs. This design also offers variable bandwidth. Reliability concerns of RF MEMS like stiction has been taken care of by using float metal based approach in this design. The proposed compact MEMS switch incorporates four cantilever beams to be used in various configurations. We have simulated the RF performance by actuating these beams in different configurations. The switch shows very promising results including isolation of >30 dB in X band, >45 dB in C band, >44 dB in F band with bandwidth ranging from narrow 5 GHz to wide 48 GHz with high isolation and till 100 GHz bandwidth with moderate RF performance.