Ultra-Selective Constant-Bandwidth Electromechanically Tunable HTS Filters

We report a tuning from 770 MHz up to 930 MHz, which is about 20%, was demonstrated. Insertion loss was 0.7 dB at 770 MHz and 1.6 dB at 930 MHz. Coupling bandwidth was kept almost constant over the entire range. A novel filter configuration and tuning algorithm is proposed and demonstrated