Computer model for a circular symmetric cavity with application for lens antennas

A computer model for the analysis and design of circular symmetric cavities built in stripline to distribute input power to lens antenna elements was developed. A one-mode (TEM) approximation is used for the fields on the stripline. Coupling between neighboring lines is accounted for by using a periodic structure approach. A taper in stripline width for impedance matching is included. Numerical results are compared with measurements and independent computations. Numerical accuracy is on the order of + or - 2 dB, but measurements were made on a microstrip cavity, and measuring accuracy is unknown. There is an unexplained difference in the computed coupling coefficient when using the cavity input impedance or the input admittance for the cavity-stripline junction problem.