COUPLING PARAMETERS FOR CAPACITATIVELY COUPLED ORTHOGONAL MICROSTRIP BRANCH LINES

Capacitance and inductance equivalent circuit parameters for various m icrostrip discontinuities were reported more than 20 years ago, but th ose for capacitatively coupled orthogonal microstrip branch lines were not included. These structures are used for ring resonators and in a class of band-stop filter. The method of moments has been used to find these parameters. A simple basis function for the subareas along the edges of the conductors allows for the charge singularity, giving fair accuracy for a reasonable number of subareas. The series coupling cap acitance is 20-40% larger than end-coupled lines with an equal gap, ev en for small gaps. (C) 1998 John Wiley & Sons, Inc.