Fullwave analysis of a strip crossover
Abstract
A fullwave analysis of a strip crossover above a conducting plane is carried out. Higherorder modes are excited in the form of evanescent waves in the vicinity of the discontinuity, while further away only the dominant (TEM) modes exist. The higherorder mode currents are modeled by triangle functions and the dominant modes by outgoing traveling waves. The method of moments is used to reduce the integral equations on the surface of each strip to matrix equations whose solution determines the currents on each strip. The impedance and scattering matrices of the fourport network and the equivalent circuit were determined. At low frequencies, the equivalent circuit agrees very well with that which was obtained previously using a quasistatic analysis. The two approaches begin to disagree when the crosssectional dimensions of the crossover become comparable to a tenth of the wavelength. At that point the quasistatic analysis becomes inaccurate, while the fullwave analysis presented here remains valid.
 Publication:

IEEE Transactions on Microwave Theory Techniques
 Pub Date:
 October 1990
 DOI:
 10.1109/22.58683
 Bibcode:
 1990ITMTT..38.1439P
 Keywords:

 Crossovers;
 Equivalent Circuits;
 Strip Transmission Lines;
 Evanescence;
 Matrix Methods;
 Traveling Waves;
 Electronics and Electrical Engineering