Dual-sleeve wideband monopole antenna for shipborne systems in VHF band

Abstract

A dual-sleeve wideband monopole antenna with loaded plasma cylinders is proposed for shipborne systems in lower very high frequency (VHF) range. The monopole with sleeves, engineered as vertical polarised element, operates at the frequency from 30 to 100 MHz. It performs good radiation ability with low elevation angle in E-plane. The monopole antenna height over feed point is 0.33? at the lowest band. Plasma cylinder array as reflector is mounted above the monopole to restrain the deformation of patterns. Impedance and pattern measurements are conducted; the VSWR = 2:1 bandwidth of the sleeve antenna is >107%. Unmanned aerial vehicle system is introduced to measure the radiation patterns at 110 MHz. Obtained results confirm that the proposed antenna is a variable candidate for communications with ships and flying vehicles in anti-stealth systems.