Design and performance of CPW and CPW bandpass filter on SOI substrate

SOI technology gets more and more interests in RF ICs for its low loss, low crosstalk and other excellent electromagnetic properties. Well-behaved passive devices on SOI substrate will contribute a lot to the entire performance of RF ICs. In this paper, the influence of SOI parameters on transmission characteristics of coplanar waveguide (CPW) is researched by HFSS simulation. Based on the fine performance of a 50 Omega CPW fabricated on an available SOI substrate, a dual-termination coupled Ka band bandpass filter (BPF) has been designed and fabricated. It shows -4.23 dB insertion loss at peak transmission of about 32 GHz. The CPW and BPF realized on SOI gain close characteristics respectively to the same structure on high resistivity (rho ges1000 Omegamiddotcm) silicon substrate. SOI shows great potential to be the substrate of RF IC.