Novel DC-40 GHz MEMS series-shunt switch for high isolation and high power applications

Abstract

This paper presents the design, fabrication, and characterization of a lateral contact series-shunt ohmic RF microelectromechanical systems (MEMS) switch actuated by an electrothermal actuator. Since the proposed RF MEMS switch is actuated electrothermally, it can be operated at an extremely low operation voltage of 0.16V. In this switch, two series switches are cascaded by a quarter wavelength section of transmission line suspended over the trench of the substrate to form a series-shunt configuration according to the principle of impedance transforming. By using a single bidirectional thermal MEMS actuator to control the signal, the switch provides higher reliability when through high power microwave signal. The measured results show that an insertion loss of 1.2dB or better is achieved from DC-40GHz. The isolation is −50dB at 5GHz, −45dB at 20GHz and −60dB at 35GHz. What is more, this switch also exhibits high linearity, and high power handing for DC-40-GHz applications. In the switch OFF state, self-actuation does not happen up to the input power of 40dBm at 1GHz. In the switch ON state, no significant insertion loss variations or problems in the contacts, due to the RF power, can be observed below 31dBm input power.