A Superconducting Dual-Band Bandpass Filter for IF Signals of Multi-Frequency Millimeter-Wave Atmospheric Spectrometer

The high temperature superconductor (HTS) dual-band bandpass filter (DB-BPF) has been developed for microwave intermediate frequency (IF) signals (8--12 GHz) of a multi-frequency millimeter-wave atmospheric spectrometer. The HTS DB-BPF consists of 6-pole and 12-pole BPFs with an 8.348 GHz center frequency and 0.27 GHz band width and an 11.156 GHz center frequency and 1.46 GHz band width, respectively. The HTS DB-BPF was fabricated using YBa ₂ Cu ₃ O _y thin films on R-Al ₂ O ₃ substrate. Fabricated DB-BPF is evaluated by experiment and simulation with good agreement. We started the long-term monitoring of atmospheric molecular species using DB-BPF at Syowa station in Antarctica.