Fabrication of HTS Microstrip Bandpass Filters using CeO$_2$ buffered YBCO Films grown on ${\alpha}\;Al_2O_3$ substrates

CeO$_2$ 버퍼막과 함께 ${\alpha}\;-Al_2O_3$ 기판 위에 성장된 YBCO 박막을 사용한 HTS Microscrp Bandpass filter의 제작

We fabricated a new hairpin type HTS 2-pole microstrip Bandpass filter to operate at 5.8GHz. The fabrication method was pulsed laser deposition and YBCO films were deposited on ${\alpha}$-A1$_2O_3$ substrates with a CeO$_2$ thin layer as a buffer layer. We developed a new style hairpin type filter by using interdigitide innerpole. Compared to the saute size regular hairpin type filters, our filter had a lower center frequency, bandwidth and loss by an amount of 14.5%, 29.6%, 0.5488dB, respectively. The size of the filters were 13.7${\times}$3.3mm. We did simulations on the several types of band pass filters by using HFSS and serenade. We measured growth rate and Tc of YBCO films grown on CeO$_2$/ ${\alpha}$-A1$_2O_3$ substrates which were rotated while growing films.