A 12–16 GHz microelectromechanical system-switchable bandpass filter

This paper describes a novel monolithic switchable filter covering a bandpass frequency of 12–16 GHz at the Ku-band on a silicon substrate. The filter structure is based on parallel-coupled half-wavelength resonator topologies and microelectromechanical system-tunable resonators designed by placing ohmic switches at the open ends of the microstrip resonators. A wideband coplanar waveguide is designed for microstrip transition without via holes during wafer testing. The measured results show a minimum insertion loss of 3.6 dB, a return loss better than 15 dB, a 10.2% fractional bandwidth and a 14.2% tuning range from 13 to 15 GHz. The fabricated filter has a chip area of 15.1 mm × 3 mm and has achieved skirt slopes of over 30 dB GHz−1.