The characteristic mode theory of the field penetration into a cylindrical waveguide through a rectangular aperture, TE case

This paper presents the characteristic mode theory method to solve the aperture problem for a cylindrical conducting guide coupled to open half space through a rectangular aperture. The equivalence principle is used to divide the problem into two equivalent regions. The decoupling of these two regions is done by short-circuiting the aperture and introducing magnetic currents of different signs on both sides of the short-circuited apertures to satisfy boundary condition. A method of solution of the operator equation in terms of eigen functions of the operator is also used in this paper. The geometry of the dielectric filled conducting cylinder with longitudinal slot is illuminated by a TE plane wave.