Electromagnetic wave diffraction by a narrow slot in proximity to a parallel screen

The paper is concerned with the diffraction of an electromagnetic wave by a narrow slot (the slot width, d, is much less than the slot length, l, and the wavelength) in the wall of an infinite plane waveguide whose height, b, is much less than the wavelength. It is shown that for any d/b, the longitudinal component of the aperture electric field is negligibly small as compared with the transverse component. A problem concerning H(10) wave diffraction by a narrow transverse slot in the common wide wall of two rectangular waveguides, one of which has a standard height and the other a height much less than standard, is examined as an example. It is shown that the proximity of a parallel screen significantly affects the slot resonance properties.