A Novel Gain-Enhanced Miniaturized and Lightweight Vivaldi Antenna

In this article, we present the design, prototyping, and characterization of an electrically smaller (
$0.36\lambda _{{0}} \times 0.29\lambda _{{0}} \times 0.002\lambda _{{0}}$
) Vivaldi antenna with enhanced gain performance. The antenna covers a bandwidth of 450 MHz–10 GHz with an average forward realized gain of 10.82 dBi. By applying a novel technique called “cascaded cavity-based substrate cut-out (CCSC),” we were able to increase the low-frequency gain within an electrically smaller Vivaldi antenna. Because the dielectric material has been removed around cavity locations, the antenna’s overall weight is reduced, giving it a high gain per unit substrate weight/volume. The high-frequency gain of the antenna has been improved with a pixelated bilayer metallic director, which flattens the antenna’s overall gain profile over a wider band range. The antenna was constructed using a low-loss RT/duroid 5880 board. The measurement results match the simulation satisfactorily.