Theoretical analysis of hybrid modes in a dual-depth corrugated waveguide feed

The propagation behaviour of dual-depth corrugated feeds is considered with particular reference to application of such structures for frequency reuse applications in satellite communication antennas. Results are presented which enable a feed to be designed operating under balanced hybrid condition at two predetermined frequencies. It is shown that at the higher balanced hybrid frequency the EHmn modes radiate with a maximum on axis with zero crosspolarisation, whereas at the lower balanced hybrid frequency the HEmn modes show these characteristics.