RF MEMS activities at IMETU

The research activities on RF-MEMS devices at IMETU (Institute of Microelectronics of Tsinghua University) are presented in this paper. The RF MEMS devices investigated include micro-machined inductors, switches, voltage controlled capacitors. The recent research focus is RF-MEMS switches. Two recently developed DC-contact switches are demonstrated, one is with series configuration and another is shunt. The two types of RF MEMS switch base on the same fabrication process. Borofloattrade glass was used as substrate and a special electroplating process is used to realize the low stress bridge membrane, which assure not only the possible power handling but also a low contact resistance. High performance switches with low insertion loss and high isolation have been obtained with very long life cycle more than 100M times. The S parameters characterization shows the DC-contact series RF MEMS switch is suitable for the application of frequency range from DC to 20 GHz, and the DC-contact shunt RF MEMS switch is suitable for the application of frequency range from DC to 30 GHz.