An Hts Filter Subsystem for 800MHz Mobile Communication System

In this paper, we present a high temperature superconducting (HTS) Filter subsystem, which consists of a 14-pole HTS filter, a low noise amplifier (LNA), a Stirling Cooler and an electronic control system. The HTS filter has a 2.1% fractional bandwidth at 814MHz. It was fabricated on MgO substrate which was double sides coated with YBCO thin films. The insertion loss of the HTS filter is less than 0.2dB, the gain of the subsystem is 22dB at 60K. In this subsystem, the out-of-band rejection is better than 70dB and the steepness of the band-edges is larger than 25dB/MHz at 60K.