Title :
Mixed lumped and distributed network applied to superconducting thin-film broadband impedance transforming
Author :
Lizhong Zhu ; Linne´r, L.J.P.
Author_Institution :
Dept. of Electr. & Comput. Eng., Waterloo Univ., Ont., Canada
Abstract :
In this paper, a detailed analysis of the properties of mixed lumped and distributed (MLD) lossless elements is first carried out. It is found that such networks can be used as extreme impedance transformers between source and load impedances without large variations in wave impedance values. Then, the lossy transformation technique (LTT) is extended to the design of MLD lossy networks. Finally, to exhibit the practical use of the new method, three examples are given for transforming extremely low input impedance of a superconducting device to a 50 Omega microwave system with the MLD networks. The outstanding advantage using this method is that transformers can be made considerably shorter than by common methods and still physically realizable. The length of the building element is reduced from lambda /4 to lambda /16.<>
Keywords :
distributed parameter networks; high-temperature superconductors; impedance convertors; impedance matching; linear network synthesis; lumped parameter networks; superconducting microwave devices; superconducting thin films; 50 ohm; MLD lossy network design; building element length reduction; distributed lossless elements; extremely low input impedance; high temperature superconductor; impedance transformers; lossy transformation technique; lumped lossless elements; microwave system; mixed lumped/distributed network; superconducting thin-film broadband impedance transforming; Chebyshev approximation; Impedance; Superconducting devices; Superconducting integrated circuits; Superconducting microwave devices; Superconducting thin films; Superconducting transmission lines; Thin film circuits; Thin film devices; Transformers;
Journal_Title :
Applied Superconductivity, IEEE Transactions on
