Analysis and design of an ultra-wideband nested coaxial waveguide feed

In this paper a four-cavity 60:1 frequency bandwidth (1-60 GHz) ultra-wideband nested coaxial waveguide feed with extended center conductors is designed and analyzed. The performance of the feed is presented and discussed in detail. The feed has less than -10 dB reflection loss over its operating frequency. The excitation of the coaxial cavities is accomplished by impressing a circularly polarized TE/sub 11/ coaxial waveguide mode. The correlated parameters are rigorously carried out by experimental measurement (1-8 GHz) and a finite element method (FEM) computer simulation study (8-60 GHz).