Design of an orthomode launcher using finite element CAD software

Launching circular polarisation is a sought after specification in some radar systems because it offers a good means of suppressing rain clutter. The paper describes the design of an orthomode launcher in waveguide size WG6 to operate at D-band capable of handling peak powers in excess of 1.5 MW. Owing to the bulk and weight of this waveguide size it was decided to obviate if possible the building of a prototype. With the advent of powerful computer-aided engineering tools these structures can be accurately modelled and fully characterized before any metal is cut thus resulting in substantial savings in time and money