THE COAXIAL WAVEGUIDE ANTENNA - A NATURAL DESIGN FOR MULTI-BAND FEED APPLICATIONS

Abstract

The coaxial waveguide antenna exhibits efficient multi-band operation in both tracking and nontracking applications. Radiation from coaxial waveguide operating in the TE1,1 mode produces an on-axis pattern similar to that of open-ended circular waveguide. A second mode, the TE2,1 mode, produces a difference pattern similar to that of a four arm spiral. An inner waveguide cavity operating in the TE1,1 mode and a concentric outer waveguide cavity simultaneously operating in the TE2,1 mode provides this antenna the ability to operate as a tracking feed. It is the intent of this paper to show how the coaxial waveguide antenna is ideally suited to meet many of today's antenna system requirements.