ABSTRACTThe main objective of this research is to present an effective technique to solve the problem of hollow rectangular waveguide. The second objective is to examine the influence of the hollow rectangular waveguide with dielectric material between the hollow rectangle and the metal on the output field. The proposed technique is very effective in relation to the analytical methods because it allows to calculate any discontinuous problem in the cross section. The contribution is important in that it is an improvement over the earlier method that was based on the Laplace and Fourier transforms and the inverse Laplace and Fourier transforms and also that it is capable to analyze the physical discontinuity in a hollow rectangular waveguide. A comparison with the known transcendental equation will show in order to examine the validity of the theoretical model. We can predict the waveguide parameters for obtaining the Gaussian behavior of the output field. The application is useful for straight hollow rectangular waveguides with dielectric material between the hollow rectangle and the metal in the microwave regime. The application can be practical in the laboratory by connecting the hollow waveguide to the analyzer spectrum in order to analyze the effect of the dielectric profile on the behavior of the waveguide.