High Gain Dual‐Slot Vivaldi Antenna Based on Elliptical Slots and Metamaterial

ABSTRACT This paper presents a dual‐slot Vivaldi antenna incorporating elliptical slots and metamaterial structures, featuring ultra‐wideband (UWB) operation and high gain. The proposed antenna achieves bandwidth extension through corner‐cutting techniques and optimization of the T‐junction power divider and radiating patch dimensions. To enhance gain performance, five pairs of tapering inclined elliptical slots are strategically etched on the edge of the radiating patch, while metamaterial structures are integrated into the antenna aperture. The synergistic integration of these structures effectively tailors the surface current distribution and electric field patterns, enhancing the antenna's aperture radiation efficiency. This yields a maximum gain enhancement of approximately 2.3 dB without altering the antenna's physical dimensions. The antenna exhibits a compact profile of 130 mm × 86 mm × 0.787 mm, with an ultra‐wide operating band of 1.3–12.0 GHz. It consistently attains gain exceeding 10dBi across most operation frequencies, and even in the frequency range of 5.5–12.0 GHz, its gain exceeds 12.0 dBi. Notably, both the E‐plane and H‐plane radiation patterns exhibit extremely narrow half‐power beamwidths (HPBW) and high directivity. The average HPBW of the E‐plane is 31.7°, with a minimum of 16.2° at 12 GHz, while that of the H‐plane is 60.4°, with a minimum of 30.9° at 12 GHz. These attributes make the proposed antenna highly suitable for advanced microwave imaging systems.