Comparison frequency responses of hairpin type superconducting and copper bandpass filters

헤어핀 초전도체 필터와 구리 필터의 주파수 응답비교

For the performance enhancement of communication system, high quality filters are required. Also a minimization of size of filter is required for the interation of devices in the limited area. Conventional metal filters made of copper can be substituted by high quality high temperature superconducting(HTS) films for better performance. Hairpin type filters have been designed with the center frequency 14 GHz for the size reduction. 3-pole and 4-pole filters centered at 14 GHz with the bandwidth of about 300 MHz were designed and fabricated. With the simulation results, the frequency responses showed low insertion loss and sharp skirts characteristics. The frequency response of HTS 14 GHz fi1ter was measured at 77 K and compared with the simulation results. We have compared YBCO filters and copper filters which were made with the same design rules. Simulated and measured frequency responses reveal that HTS YBCO hairpin type bandpass filters show better performance than copper filters.