High‐Gain Filtering Antipodal Vivaldi Antenna Incorporating Spoof Surface Plasmon Polaritons and Directors

ABSTRACT In this letter, a filtering antipodal Vivaldi antenna (AVA) integrating spoof surface plasmon polaritons (SSPPs) and directors, featuring controllable passband characteristics and high gain, is proposed. In the antenna configuration, a set of slots etched along the outer edges of the radiation arms improves the low‐frequency gain, while antenna‐terminal‐loaded semi‐annular directors further enhance the overall gain. The filtering characteristics can be conveniently tuned by adjusting the dimensions of the branched circular metallic patch and the SSPPs structure. A prototype operating from 7.44 to 11.76 GHz was fabricated and experimentally characterized to validate the design. Measurement results demonstrate an impedance bandwidth of 45%, stable in‐band gain with a peak value of 12.14 dBi, and inherent advantages of wide bandwidth and low profile. Compared with conventional AVAs, the proposed design exhibits improved radiation characteristics, achieving both higher gain and superior filtering performance.