A HTS bandpass filter for a meteorological radar system and its field tests

This paper presents recent progress of a high temperature superconducting (HTS) filter designed for a meteorological radar system (wind profiler) and its field tests results. The filter was designed to exhibit a ten-pole quasi-elliptic response with a fractional bandwidth of 0.35% in L band. It was fabricated using double-sided YBCO films on a 50-mm-diameter, 0.5-mm-thick MgO substrate. A HTS subsystem was assembled by connecting the filter with a cryogenic low noise amplifier (LNA), fixing them on a cryocooler and enclosing in a cryopackage. With the HTS subsystem substituting the corresponding conventional part (the conventional subsystem) of the wind profiler, two stages of experiments including field test were carried out. The first stage experimental results showed that while employing the HTS subsystem the sensitivity of the wind profiler improves 3.7 dB and the anti-interference ability improves 48.4 dB. The second stage experiment-field test results snowed the improvement visually through the wind charts and wind profiles obtained in the field trial.