Research on a novel balanced antipodal vivaldi antenna for MMW imaging system

A novel balanced antipodal Vivaldi antenna (BAVA) with asymmetric substrate cut-out and tapered slot edge (TSE) is designed to be used as a sensor for a MMW imaging system. Research on these novel features is demonstrated to enhance the gain by an average of 2dB over a band of 10–40GHz and greatly reduce the beam-tilting at E plane, which is considered to be the major defect of conventional BAVA. Furthermore, the new antenna has much lower side lobes than the conventional one, which enables this antenna to be used in an H-plane array structure. The simulated reflection coefficient is found to be less than −12 dB over a frequency range of 10–40 GHz. And the extremely wide band can fulfill the potential of higher range resolution for MMW imaging system.