An estimate of the intensity in the oval slot of a metal plate placed cross in a rectangular waveguide

Summary form only given. It is known that to expand the frequency bandwidth of slot antennas, slots with semicircular edges must be applied. In this paper an algorithm for estimating the intensity in the oval slot of a metal plate placed cross in a rectangular waveguide is proposed. It is assumed that the edges of the slot are in the form of a semicircle and the fundamental wave mode is propagated in the rectangular waveguide. The intensity in the slot is determined by an area integral. The integral area consist of a central fragment and two semicircular parts. The resolves of the area integrals are implemented. To achieve this the two-fold substitution, Newtonian binomial formula, and integral expansion are applied. The derived analytical expressions allow one to examine the influence of the description and dimensions of the slot to the intensity as well as the emitted and received powers of the slot antennas. The results can be used in the investigation of the intensity amplitude distribution in array radar antennas with oval slots.