Broadband MEMS shunt switches using PZT/HfO2 multi-layered high k dielectrics for high switching isolation

A novel approach using a PZT/HfO2 multi-layered dielectric for capacitive type MEMS switches was investigated. Compared to Si3N4, PZT/HfO2 demonstrated a high equivalent dielectric constant of 79-82 and a low leakage current density of 1.58 × 10−6 A/cm2 after a bias stressing time of 104 s, that result in high switching isolation and very low power consumption. In addition, a finite element analysis was used to estimate actuation voltage, insertion loss and isolation performance of one-bridge and π-match switches. After manufacturing, the experimental results of the π-match switch showed an acceptable insertion loss of less than −0.5 dB in a frequency band of 50 MHz-20 GHz and significantly high isolation of −30 to −65 dB in a broad frequency band of 50 MHz-57 GHz.