The improvement of Tri-Plate performance by using corrugated transitions

A novel structure is investigated for the improvement of Tri-Plate performance. Based on the experience in the design of horn antennas, we introduce corrugations of the transition section of the Tri-Plate in order to achieve better field uniformity and to reduce the return loss. A corrugated transition waveguide may be viewed as the cascade of bifurcated metal waveguides, and we employed the building-block approach which breaks the overall structure into cascaded sub-cells, each of which may be analyzed rigorously by the mode-matching method. Thus, the input-output relation of each sub-cell is obtained and so is that of the overall structure. This enables us to carry out a parameteric study on the field distribution inside the Tri-Plate, so that we can optimize its design for any required specifications.