Tunable high-isolation W-band bandstop filters

Widely tunable, high-isolation W-band bandstop filters realized with evanescent-mode resonators are presented. These filters exhibit large notch depths of up to 70 dB, with 3-dB bandwidths as narrow as 1.5% and out-of-band insertion loss of less than 3.25 dB. Two filters are presented, which have 75-103 GHz and 96-108 GHz tuning ranges. These filters are fabricated using all-silicon technology, and are tuned with low-power electrostatic actuators which have bias voltages of less than 90V. The demonstrated filters have the potential to enable robust W-band communication systems which can operate in the presence of large interfering signals.