Linearly Flared Enhanced Antipodal Vivaldi Antenna Design

This paper presents a novel linearly flared antipodal Vivaldi antenna design for Ultra-Wideband (UWB) applications, addressing the limitations of traditional exponential flaring. The proposed antenna eliminates the need for complex exponential curves while maintaining broad impedance bandwidth and improved gain. Fabricated on a compact 50 × 32 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> FR4 substrate with a 1.6 mm thickness, the design ensures miniaturization without compromising performance. Experimental validation using a Vector Network Analyzer (VNA) confirms an impedance bandwidth of 1.56 GHz to beyond 15 GHz, achieving a bandwidth percentage of 174%. Measured results in an anechoic chamber demonstrate a peak gain of 13.17 dBi and an average gain of 7.61 dBi, showcasing excellent directivity. Theoretical analysis, supported by surface current distribution, further validates the effectiveness of the linear flaring approach in enhancing radiation characteristics. This design provides a compact, high-gain solution for UWB applications.