Fifteen pole superconducting filter for radio astronomy

Application of high temperature superconducting (HTS) materials in the communication industry has become attractive in recent years. Mobile communications, radar, radio telescopes and satellite communication links are some of the many applications which use microwave filters made from HTS materials. Most HTS microwave filters reported in the literature were designed for narrow band applications; this is due to recent commercial requirements. However, some astronomy laboratories need to employ a fairly wide band filter for their radio telescope receivers. An HTS filter is ideal for this application because of the low intrinsic insertion loss and steep filter skirts. A fifteenth order Chebyshev HTS band pass filter, designed for Jodrell Bank Observatory, is presented for astronomy applications. Sonnet EM simulation results are provided for this 15-order filter with fractional bandwidth of 26.4%. Good agreement between theoretical results and simulations is obtained. Size miniaturization has also been carried out. Comparisons of simulation results between original and minimized design are also provided.