Method for Calculating Radiation Characteristics of Dual-Reflector Antennas with Resonance Size Reflectors of Finite Thickness and Conductivity

Abstract

The paper presents a method for calculating the radiation patterns (RP) of dual-reflector antenna systems taking into account the electrodynamic interaction between reflectors. This method is suitable for use in the resonance range of wavelengths with respect to the main dimensions of reflectors. The method is based on the iteration procedure proposed by the authors. Each iteration involves the use of the method for calculating the scattering of electromagnetic wave by unclosed screens of finite thickness and conductivity that is suitable for use in resonance range. The specified method is based on applying the E-field integral equation that takes into account the Leontovich approximate boundary conditions on impedance surface and makes it possible to take into account the real thickness and conductivity of antenna’s reflectors. The paper presents the results of calculating RP of dual-reflector antennas built in accordance with the Gregorian scheme for different sizes of small reflector aperture and different arrangements of feeder at the fixed size of large reflector. The paths of reducing the level of the first side lobes of RP are shown. The specified reduction is achieved at the expense of the feeder proper placing with respect to the small reflector of antenna.