Corrugated Waveguide Feeders for Microwave Antennas

The use of corrugated waveguide as feeders for microwave antennas is discussed. They offer the advantage of a potentially lower attenuation than smooth wall circular waveguides. As circular corrugated waveguide feeders are slightly overmoded, we describe results showing that the mode conversion due to bends has negligible affect on the dominant mode radiation pattern. We also discuss a means to provide continual mode suppression. Finally, the cross-polarisation properties of corrugated waveguides are found to be intrinsically superior to those of smooth wall waveguides when the waveguide wall suffers elliptical deformation.