Design and Performance Prediction of a Dual-Band Coupled-Fed Dipole Array Antenna for PCL Systems in the VHF Band

This article proposes the design of a dual-band coupled-fed dipole antenna for passive coherent location (PCL) systems in the very high frequency (VHF) band. The proposed indirect coupled feed mechanism, which is often employed in microstrip patch antennas, is first applied to VHF band dipole elements for dual-band matching. To confirm the effectiveness of the proposed design, we fabricate the coupled-fed dipole element and measure antenna characteristics, such as the voltage standing wave ratio (VSWR) and the antenna gain. The proposed antenna element is then applied to an eight-element circular array to form the reference and surveillance beams for PCL systems. Finally, the target location is estimated by constructing amplitude-range doppler (ARD) maps for one frequency modulation (FM) and two terrain digital multimedia broadcasting (T-DMB) illuminators in the Seoul-Gyunggi urban area. The results confirm that the proposed element is suitable for dual-band PCL systems in the VHF band compared to a conventional dipole antenna.