Wideband and low-loss waveguides of nonuniform cross-section
Waveguides of nonuniform cross-section are introduced, analyzed and then their cross-section is optimized to reach wideband and low-loss waveguides. The waveguide cross-section is defined as a Fourier series whose unknown coefficients are optimized using genetic algorithm to reach a proper cross-section for waveguide. A verified finite difference method is used in analysis stage of optimization. The results show that optimum designed nonuniform cross-section waveguides have lower conductor attenuation constant in comparison with double ridged waveguides of the same bandwidth.  2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:115121, 2015.
wideband low-loss finite difference method nonuniform cross-section waveguides cutoff frequency