A Prototype of Helmet Antenna with Omnidirectional Radiation Pattern for VHF

Abstract

A novel helmet antenna using a disk-loaded monopole antenna is proposed. This helmet antenna operates at the very high frequency (VHF) band with omnidirectional and vertically polarized radiation pattern in the horizontal plane. Moreover, by loading an annular slit on the outer shell and an annular short on the edge of the inner and outer shell, this proposed antenna is reduced radiation toward the human head. The proposed antenna is prototyped and measured and compared with the simulated results.