Characterisation of a small switchable ribbon monopole antenna operating in VHF/UHF bands

This paper describes the development of a small ribbon monopole antenna for UHF and VHF frequency maritime applications. A LC-matching circuit is used to have the antenna resonance in VHF band. In order to have a compact structure a device is used to switch between the two bands (UHF and VHF). Experimental and numerical results demonstrate that the proposed antenna exhibits a bandwidth of approximately 12.3% and 4% for UHF (420 MHz) and VHF (167 MHz) respectively. The total efficiency of the antenna was measured with two methods (reverberation chamber and Wheeler cap): it was higher than 90% in the both UHF and VHF bands. A switch device was introduced to have one antenna, and good results were obtained. Gain measurement is performed in UHF band.