Centre frequency and bandwidth tunable bandpass filter based on RF MEMS (10-14 GHz)

This paper presents a novel tunable bandpass filter design with independent control of both the centre frequency and the bandwidth by means of analogue-series and digital-shunt MEMS capacitors. The filter is designed for operation in X and Ku bands with 4 pre-selected Centre frequencies (from 10 GHz to 14 GHz) and with a bandwidth tunability of 70% (variable between 500 MHz and 1 GHz). The filter originally includes a fine frequency tuning to correct the Centre frequency position that slightly and intrinsically shifts when tuning the bandwidth. An accurate physical circuit model is proposed and demonstrated to be in good agreement with the full-wave simulations. The devices are currently under fabrication and measurements results will be presented at the conference.