A compact narrowband HTS microstrip filter for PCS applications

We have fabricated a compact narrowband microstrip hairpin-comb filter for PCS applications by patterning double-sided YBCO films prepared by pulsed l aser deposition on a 50-mm-diameter, 0.5-mm-thick LaAlO3 wafer. To achieve the desired performance with the size limitation, folded half-wavelength re sonators are all oriented in the same direction. We design the filter with the aid of a commercially available full-wave EM simulator, ENSEMBLE, which is based on the method of moment. The Ii-pole filter has a 0.6 dB minimum insertion loss and 11.5 MHz bandwidth at 1.778 GHz, and shows a very sharp skirt and strong stopband characteristics. The measurement data are in good agreement with the simulated result.