Metamaterial surface and modified Vivaldi antenna to tune gain of microwave imaging instrument

Abstract

Abstract This work presents the design of a modified Vivaldi antenna, a metamaterial structure and their combined utilization for tuning the gain. Two triangular shaped conducting patches are used to form a (5 mm × 5 mm) unit metamaterial structure, which is used on the Vivaldi antenna to enhance the bandwidth and the gain. The proposed antenna has a −10 dB bandwidth of 17.36 GHz ranging from 3.3 to 21.6 GHz. The absorption capability of the metamaterial structure is observed for multiple polarization angles and the corresponding losses are also measured. The metamaterial surface, made up of periodic arrays of the proposed structure, is further implemented to tune the gain of the antenna, to make an application-independent near-field microwave imaging instrument.