Hybrid RF-MEMS Switches Realized in SOI Wafers by Bulk Micromachining

This paper presents an RF microelectromechanical systems (MEMS) switch based on hybrid technology. Electromechanical, microwave, and fabrication design considerations are presented. The methodology is illustrated using shunt contact MEMS switches. The fabrication of the MEMS devices was performed using bulk micromachining processing of a silicon-on-insulator wafer, followed by vertical (3-D) integration with a microwave coplanar transmission line on a GaAs and silicon substrates. The electromechanical and RF performance of the switch were characterized. An isolation of 34 dB at 35 GHz and an insertion loss of 0.1 dB at 35 GHz for a shunt switch were achieved. The concept of a packaged RF switch described in this paper enables a modular implementation of a flexible switch design, independent of the RF circuit substrate material or technology being used.