C-Ku band reflection-type RF-MEMS tunable BPF

In this paper, we propose a low loss tunable band pass filter (BPF) with direct contact RF-MEMS switches. To reduce the insertion loss in the pass band, reflection-type architecture is implemented. To obtain wide tuning range and sharp characteristics, a lumped-element configuration is adopted. We prove the reflection loss of a tunable BRF whose lumped- elements were changed over by the direct contact switches, is much lower than the insertion loss of a tunable BPF of the same system. Finally, we validate the concept by the trial fabrication, showing the loss of 3.2 dB, 2.8 dB and 3.5 dB at the center of the three selectable frequencies over the C-Ku bands.