介质谐振器法测量高温超导薄膜微波表面电阻的误差分析

用微扰法研究了两端接地型蓝宝石介质谐振器测量高温超导薄膜微波表面电阻R_S的误差与几何结构和工作频率的关系.结果表明,介质柱直径与高度之比2a/L,金属屏蔽腔内半径与介质柱半径之比b/a以及工作频率f对测量误差和最小可测表面电阻R_smin有很大影响.所得到的曲线可用于蓝宝石介质谐振器的设计中.结果还表明,适当选取2a/L,b/a与f可使测量误差接近于1%,最小可测表面电阻R_smin可达到微欧姆的数量级.这对于高温超导薄膜的检测和微波器件应用说 关键词： 介质谐振器 高温超导薄膜 微波表面电阻 误差分析

ERROR ANALYSIS FOR MEASUREMENTS OF MICROWAVE SURFACE RESISTANCE OF HIGH-TEMPERATURE SUPERCONDUCTORS BYDIELECTRIC RESONATOR METHOD

In this paper the relations between the errors in measurements for the microwave surface resistance of a high-temperature superconducting thin film and the geometry and frequency of a parallel plate dielectric resonator were analyzed. The results showed that the influence of the 2a/L(ratio of the diameter of the dielectric rod to its length), the b/a (ratio of the radius of the metal cavity to the radius of the dielectric rod) and the frequency f on the error and the measurable minimum surface resistance R_smin is quite important. The curves obtained in this paper could be used to design the dielectric resonators of parallel plate type. The error of order of 1% and R_smin of the order of micro-ohm could be obtained by proper choosing 2a/L, b/a and f.