Design and development of low loss microstrip band pass filters by using YBCO- high temperature superconducting thin film

摘要

To demonstrate the suitability of HTS filters we chose a four pole chebyshev band pass filter with 80 MHz band width, insertion loss of 0.5dB at 4035 MHz center frequency on LaAlO3 single crystal with YBCO HTS thin film. The filter was designed with four-pole quarter wave parallel-coupled line. To check the validity of filter design, two filters were fabricated using gold thin films of 0.5 microns thickness on 0.5mm thick LaAlO3. The filter showed an insertion loss of 8.5 dB at the pass band at room temperature and 3.5 dB at 77°K.