Design and Analysis of a Dual-Band Vivaldi Antenna for Wideband Wireless Applications

This paper presents the design and numerical analysis of a compact dualband Vivaldi antenna operating in the C-band region. The antenna is realized on an FR-4 substrate (relative permittivity εr ≈ 4.4) to ensure low-cost fabrication and practical implementation. Dual-band behavior is achieved by introducing a modified exponentially tapered slot combined with a circular slot perturbation near the feed region, enabling controlled excitation of multiple resonant modes. Full-wave electromagnetic simulations demonstrate two distinct resonances at 4.55 GHz and 5.79 GHz, with excellent impedance matching levels of −63 dB and −45 dB, respectively. The proposed structure maintains stable radiation characteristics with end-fire behavior across both operating bands. Surface current analysis confirms that the lower resonance is dominated by the slot-loaded feed region, while the upper resonance is governed by the tapered aperture profile. The compact size, strong impedance matching, and simple geometry make the antenna suitable for C-band wireless communication, radar sensing, and multi-band RF applications.