Design of waveguide fed broadband circular polarization truncated horn antenna for high power applications

This paper presents the design of a waveguide fed broadband circular polarization truncated horn antenna for high power applications. It consists of a circular polarization truncated horn antenna and a truncated-square to rectangular waveguide transition. The structure does not have any internal sharp corners and has large inner dimensions in order not to pose much limit on the maximum power-handling capacity. By truncating the corners of a horn, circular polarization modes are generated. The length of the waveguide transition is critical as it affects the axial ratio and return loss of the horn antenna. The antenna has a simulated 3dB axial ratio bandwidth of 23.6% with return loss better than 20dB.