Design of UWB UHF Printed Dipole Antenna Array For Foliage Penetrating(FOPEN) Radar

This paper presents a Tightly Coupled Dipole Array (TCDA) which provides UWB performance at Ultra High Frequency (UHF) range. The array is designed to achieve a bandwidth of 111% and gain better than 7dBi over UHF band of (200 to 700) MHz This design consists of linear dipole array comprising of 3 element overlapping dipoles that are placed in a row. The overlapping dipoles are "printed" on a Rogers RT/Duroid 5880 31mil thick substrate (epsilon(r)=2.2). Feed of dipole elements requires a balanced to unbalanced transformer (balun) which acts as a transition, impedance transformer and the balun is required to be compact in size. The antenna finds its application in a UWB UHF FOPEN SAR system.