주파수 가변형 밀리미터파 필터의 제작 및 실험

Fabrication and experiment of tunable millimeter-wave filters

In this paper, new micromachined tunable bandpass filters for multi-band millimeter-wave telecommunication systems are proposed. Two types of mm-wave tunable filters are fabricated using micromachining technology and the responses of the filters are measured. One is two-pole lumped elements filter and the other two-pole resonators filter. Frequency tunability of the filter is achieved by changing the gap between a common CPW ground plate and the movable cantilever beam connected to the transmission line with the controllable range of 2.5 ${\mu}m$. The deflection of cantilever beam is measured with the applied DC voltage. With the applied bias voltage from 0 to 50 V, the fabricated filters show 0.6 GHz(2.3 %) at 26.6 GHz, and 0.8 GHz(2.5%) at 32 GHz center frequency shift for the lumped elements and resonators filter, respectively.