Micromachined coplanar waveguide band-pass filter for w-band applications

In this paper we present the design and measurements for a novel configuration of a membrane supported coplanar waveguide band-pass filter for W band applications. The topology is based on identical symmetrical elementary cells connected in cascade. The design process is based on the image impedance representation and a full-wave 3D electromagnetic (EM) model is developed. A two-cell test structure was fabricated through silicon micromachining. The measured pass-band is of 28 %, centered around 91.5 GHz. The measured losses are of 3.77 dB at the central frequency and the reflection losses go down to -20 dB, in good agreement with the simulated results. This structure was designed to be easily adapted to the BiCMOS technology with localized back-side etch (LBE) process.