Photonic band gap implementation for phase centre controlling in Vivaldi antenna

摘要

Controlling of the phase centre in ultra wideband antenna is important in localisation at radar systems as for accurate localisation, a constant or linear phase centre is required. In addition, high gain, high bandwidth and end-fire pattern are demanded in these systems. Therefore, end-fire taper slot Vivaldi antenna has been noticed because of its high gain and wide bandwidth and end fire pattern. The authors have suggested utilising photonic band gap (PBG) for making a linear phase centre of the antenna. Implementation of the PBG substrate has controlled the electric field and surface current over the antenna and compensated the distortion in phase centre and in addition improved the mutual coupling in the proposed antenna. Here, for achieving best results the parametric studies have been noticed for PBG hole diameters and arrangement of these elements is investigated studied. Furthermore, using PBG substrate has improved the antenna gain. The final prototyped antenna with PBG substrate in order to work in a wide bandwidth shows acceptable performance in the range of 6-18 GHz with VSWR <;2 antennas well as achieving a higher gain of >2-4 dBi and >90% efficiency, in comparison with conventional tapered slot antennas.