Tunable microwave filter using highly anisotropic liquid crystals

Abstract

An electrically controlled tunable microwave filter is described, which is designed on a resonant inverted microstrip structure with a nematic liquid crystal. The center frequency of the respective two-pole tunable filter is settled at 6.5GHz which can be shifted by 500MHz approximately. The device is fabricated using liquid crystal sandwich structure with a total thickness of 1 mm. The total size of the proposed filter structure is 20×18 mm2.