A High Performance HTS Filter Subsystem for CDMA

X. B. Guo ； B. S. Cao ； B. Wei ； X. P. Zhang ； Z. S. Yin ； W. J. He ； S. He ； L. M. Gao ； M. H. Zhu ； B. X. Gao ； B. Aminov ； M. Getta ； S. Kolesov ； H. Piel ； N. Pupeter ； D. Wehler

《Chinese Journal of Physics》 42卷4S期 (2004/08) Pp. 463-467

並列摘要

We designed and fabricated a 16-pole high temperature superconducting (HTS) filter with a 1.2% fractional bandwidth at 830 MHz for CDMA mobile communications. In this paper we describe the design, the test procedure and the obtained results. The filter was fabricated on a 46mm×29mm×0.43 mm sapphire substrate which was double side coated with YBCO thin films. At a temperature of 70 K, the in-band insertion loss of the filter is less than 0.29 dB, its out-of-band rejection is better than 70 dB and the steepness of the band edges is larger than 40dB/MHz. We also fabricated and tested a HTS subsystem, which consists of the 16-pole HTS filter, a low noise amplifier (LNA) and a Stirling Cooler. Cooled down to 70 K, the HTS subsystem shows a good performance of 0.75 dB noise figure and 1.5 voltage standing wave ratio (VSWR) with 21.5 dB gain.