Title :
TEM equivalent circuits for quasi-TEM couplers
Author :
Cheng, S. ; Edwards, M.L.
Author_Institution :
Whiting Sch. of Eng., Johns Hopkins Univ., Laurel, MD, USA
Abstract :
Equivalent circuits for quasi-TEM (transverse electromagnetic) coupled lines have been developed for symmetric lines (C/sub 1/=C/sub 2/) and for asymmetric lines having a congruent LC matrix. It is shown that the congruence assumption is very general. The error is insignificant provided the line width is narrower than the substrate thickness, a condition generally met in practical circuits. These equivalent circuits are easy to implement using a computer-aided engineering (CAE) system such as TOUCHSTONE, which accepts and correctly calculates ideal transmission line performance even for negative characteristic impedances.<>
Keywords :
circuit CAD; equivalent circuits; transmission line theory; waveguide couplers; TOUCHSTONE; asymmetric lines; computer-aided engineering; congruent LC matrix; equivalent circuits; ideal transmission line performance; line width; negative characteristic impedances; quasi-TEM couplers; substrate thickness; symmetric lines; Computer aided engineering; Computer errors; Couplers; Coupling circuits; Distributed parameter circuits; Electromagnetic coupling; Equivalent circuits; Symmetric matrices; Systems engineering and theory; Transmission line matrix methods;
Conference_Titel :
Microwave Symposium Digest, 1990., IEEE MTT-S International
Conference_Location :
Dallas, TX
DOI :
10.1109/MWSYM.1990.99601
