Multiport MEMS-based waveguide and coaxial switches

In this paper, a new concept of three-dimensional (3-D) multiport RF microelectromechanical systems (MEMS) switches is introduced. The proposed structures are based on integrated MEMS actuators inside 3-D waveguide and coaxial structures. These switches are well suited for high-power redundancy switch matrices for satellite communication, as well as millimeter-wave applications. To demonstrate the concept, a C-type waveguide switch is fabricated and tested. The use of a unique bi-layer curled electrostatic actuators, results in a very good RF performance with an isolation of 36-40 dB and a return loss of -20dB over a 7% bandwidth at satellite Ku-band. This paper also presents for the first time a new type of MEMS-based coaxial switch, which can offer a much larger bandwidth with miniaturized dimensions. To prove the concept, prototype units of single-pole single-throw and C-type switches are designed, fabricated, and tested. The measured results demonstrate a bandwidth of 65% for the C-type MEMS-based coaxial switch.