2004/01/26 by Alexander P. Zhuravel, Stephen Remillard, Steven M. Anlage +1
Physics and Astronomy · #cond-mat.supr-con #cond-mat.mtrl-sci
published as MSMW'04 Symposium Proceedings. Kharkov, Ukraine, June 21-26, 2004. · 3 pages, 4 figures, presented at the Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves (MSMW'04), June, 2004
arxiv created 2004/01/26 · arxiv updated 2009/12/01
Microwave resonators made from high-temperature superconducting (HTS) films are becoming increasingly commercially competitive in the market of modern communication technologies. However, unlike normal metals, the HTS device performance suffers from intrinsically nonlinear electrodynamics, resulting in harmonic generation and intermodulation (IM) distortion at all levels of circulating power. The dominant sources of IM response are believed to be inductive and localized in only small regions of the HTS film having the highest current densities JRF(x,y). In our previous papers, examining microwave resonators of simple microstrip geometry, we have demonstrated that local nonlinearity imaging is possible with the technique of low temperature laser scanning microscopy (LTLSM) adapted to microwave experiments. Unique contrast due to IM current density JIM(x,y) was generated by the IM imaging method. It was applied to display the regions showing large nonlinear LTLSM photoresponse (PR) in HTS devices with a few-micrometer spatial resolution. Direct local correlation between JIM(x,y) and high JRF(x,y) at the edges of the strips, typical defects like twindomain blocks, in-plane rotated grains and micro-cracks was shown. Here we want to indicate that the geometrical features in HTS circuit layout for microwave devices of more complex geometry also radically affect the linear device performance.