Resistors and Metamaterial on Double-Slot Antipodal Vivaldi to Enhance Bandwidth and Gain

Performances of the double-slot antipodal Vivaldi antenna have been evaluated and enhanced with added resistors and metamaterial. The near-field propagation analysis method was applied for the optimization. The new near-field characteristics of magnitude, direction of first clusters of Poynting vectors, flatness of wavefront based on Time of Arrivals (ToA) and local near-field to far-field transformation were used as criteria along with conventional characteristics in the design. The method supported detail near-field analyses on sub-structures and for their improvements such as adding the resistors and metamaterial to mitigate redundant energy on the core to flatten and increase gain.