Radiation patterns of a paraboloidal reflector fed by a pyramidal horn with lossy walls

Recent measurements carried out on a small pyramidal horn to verify the theory and to study the effect of absorbing walls on the copolar gain and radiation pattern are reported. On the basis of experimental data it is concluded that cross polarization in pyramidal horns can be reduced significantly by coating the horn walls with an absorbing material. The attenuating effect of the absorbing layer on the copolar field is found to be relatively small. A reduction of 6-dB in peak cross polarization was achieved with a loss of 0.7 dB in copolar gain. It is expected that the better results will be achieved when the horn is optimized