High-Power High-Isolation RF-MEMS Switches With Enhanced Hot-Switching Reliability Using a Shunt Protection Technique

This paper presents a shunt protection technique to improve the hot-switching reliability of metal-contact radio-frequency microelectromechanical systems (RF-MEMS) switches. The proposed technique places shunt protection contacts in front of the main contact of an RF-MEMS metal contact switch to block RF signal while the main contact is switching ON or OFF. The shunt protection contact creates a local cold-switching condition for the main contact to increase the lifetime of the switch under hot-switching condition. The shunt protection technique can also increase the overall isolation of the switch. To demonstrate the technique, RF-MEMS switches with and without shunt protection were fabricated using all metal process. Compared with the unprotected switch, the protected switch has longer lifetime under hot-switching condition. The protected switch has > 100-million cycles and up to 500-million cycles lifetime under the 1-W hot-switching condition, measured in open-air laboratory environment. Besides, the isolation of the shunt-protected switch is 70 dB at 1.0 GHz and 36 dB at 40 GHz, and the insertion loss is 0.30 dB at 1.0 GHz and 0.43 dB at 40 GHz.