A fast technique for analysis of waveguides

The authors present a new technique for fast calculation of dispersion characteristics in inhomogeneously loaded waveguides. The method calculates an approximate value of propagation constant at a desired frequency based on more accurate computations of the field distribution and propagation constant at a few selected frequency points. Numerical tests show that the relative error in propagation constant below 0.05% can easily be obtained throughout a very wide frequency band for a dominant mode using accurate data calculated at as few as four frequency points