高溫超導微波濾波器之設計與製作

Abstract

我們利用雙面的高溫超導釔鋇銅氧薄膜來製作六級的髮夾梳形帶通濾波器(hairpin-comb filter)。量測的結果顯示，兩個樣品之中特性較好的濾波器，其中心頻率在8.21GHz，比例帶寬為3%，通帶的插入損耗為4.37dB。此濾波器除了損耗稍大外，其餘的趨勢大致和電腦模擬的結果相符合。在文末，並提出了改進的方法，除了以退火技術改善薄膜表面平整度外，利用較高解析度的蝕刻方式以及在耦合 線上鍍金，都是以後可嘗試的辦法。

Two 6-pole hairpin-comb high-temperature superconductor bandpass filters have been fabricated. The better one, from the measurement results, we got 8.21GHz passband center frequency, 3% fractional bandwidthand and 4.37dB insertion loss. Although this filter had large insertion loss, the rest of the characteristics of this filter was correspondent to computer simulation. At last in this paper, we suggested some improvements of the filter, that included pre-annealing process of the substrate, high resolution etching techniques and an Au layer on the coupled lines.