Design for optimal axial ratio of spiral antenna for NLJD system

Abstract

This paper describes a design for the optimal axial ratio of the spiral antenna applied for NLJD system. To improve the axial ratio, the archimedean slit conductor on ground plane is newly designed by comparison with the conventional antenna [2]. The improved axial ratio of 3 dB below is realized by the optimized cutting slit of DFG and PGE. The measured E-field radiation patterns and the main beam directivity toward +z axis direction are agreed well with the simulated results.