CAD of E-plane circuits with field-theory based lookup tables and discontinuity models

A computer-aided design (CAD) procedure for E-plane circuits using field-theory-based lookup tables for the analysis of straight finline sections is reported. The lookup tables are generated with an accelerated spectral-domain program and interpolated with respect to frequency using physically realistic functions. This procedure reduces considerably the size of the lookup table, since only three frequency points are needed for each gapwidth. Interpolation with respect to the gapwidth is linear. Discontinuities are modeled using a combination of these lookup tables with closed-form expressions. All models have been implemented using the TOUCHSTONE SENIOR package, and thus take advantage of all capabilities inherent in this software. Agreement with measurements is good, but it is noted that this agreement ultimately depends on the accuracy of the models used.<>