Transmission Through a Narrow Slot in a Thick Conducting Screen

In this communication, the electromagnetic transmission problem through a narrow slot in a thick conducting screen is dealt with by using the modal expansion Galerkin's method in the space domain. The main concern centers on the condition for maximum power transmission through the slot in the thick conducting screen. Transmission cavity resonance phenomena, which are observed only when the resonance cavity is formed along the longitudinal direction inside the slot region in the thick conducting screen, are investigated. These transmission resonance peaks occur at particular values of the screen thickness, that is, when the thickness of the conducting screen is a little less than an integer number of half guide wavelength of the fundamental guided mode inside the slot region. It is also found that there is another type of transmission resonance phenomenon occurring regardless of the screen thickness. The latter type of transmission resonance is observed only when transverse resonance condition holds and can be taken as a generalization of the slot resonance in a thin conducting screen to that in an arbitrarily thick conducting screen.