Efficient analysis of horn antennas using WIPL code at personal computers

Horn antennas are widely used as: (a) feeds for large reflector and lens antennas, (b) high gain element in phased arrays, and (c) standard-gain antenna in antenna measurements. The classic analysis of horn antennas is based on the equivalence principle using the approximate aperture field distribution, giving satisfactory results for the main beam of the radiation pattern and antenna gain. The two dimensional GTD model including edge diffracted field yields an improvement in the E-plane pattern. But, these methods can not be efficiently used for analysis of electrically large horns. For such horns a hybrid numerical technique, combining a full-wave stepped-waveguide model and hybrid field integral equation, is developed. This hybrid technique enables very accurate evaluation of the radiation pattern, even in the back region. However, once developed for horns of circular or rectangular geometries, this technique can not be applied to other geometries. Further, it can not be efficiently used with personal computers. This technique can not evaluate the input impedance of a horn antenna if it is fed by a coaxial line. All these problems can be overcome if the WIPL code is used, as explained. The WIPL is a code for electromagnetic modeling of composite wire and plate structures.