Wideband Dual-polarized Vivaldi Antenna with Gain Enhancement

A wideband dual-polarized Vivaldi antenna covering 1.85-18.3 GHz band with enhanced gain is presented in this letter. The proposed antenna consists of two Vivaldi antenna elements (VAEs), which are designed based on the conventional Vivaldi antenna. Dual-slot structure is employed to improve the gain of the conventional Vivaldi antenna. As a result, sphericallike waves across the slot aperture of the conventional Vivaldi antenna can be transformed to be plane-like waves and thus gain enhancement can be achieved. In order to extend lower frequency limit of the VAE, elliptical slots are adopted. The proposed dual-polarized Vivaldi antenna is obtained by combining two VAEs in a cross-shaped form. The prototype is simulated, fabricated, and measured. A good agreement between EM simulated and measured results evidently validates the proposed antenna.