Coaxial-to-waveguide adapter generating circularly polarised wave

A technique of generating a circularly polarised wave by reflection type is presented using a coaxial-to-waveguide adapter. The adapter consists of a polarisation twisting section and a phase-delay section for the generation of circular polarisation in the circular waveguide. The design and the implementation of the adapter demonstrate the advantage of significant size reduction and the possibility to overcome the weight concern problems in waveguide systems.