A NEW RF MEMS CAPACITIVE SWITCH FOR K-BAND APPLICATION

This paper proposes a novel RF MEMS capacitive shunt switch, which is applied in Kband (18 ∼ 26.5 GHz). The characteristic impedance matching of the RF MEMS switch is achieved by discontinuous coplanar waveguide (DCPW) structure. Two actuation poles are located at the bottom of the fixed-fixed beam, and they are covered with a dielectric layer of SiN. The pole’s thickness is less than that of CPW signal, to avoid the phenomenon of dielectric charging between the beam and the pole. The proposed MEMS switch is fabricated on 400 μm-thickness high resistivity silicon, using the MEMS surface micromachining process. Measured results demonstrate that, at K-band, the return loss is better than 22 dB, and the insertion loss and isolation are better than 0.5 and 17 dB, respectively. The on/off switched time is 168/54 μs when the DC bias voltage is 0/54 V. This proposed MEMS switch provides a solution for K-band communication system applications.