An Improved Design of UWB Slotted Antipodal Vivaldi Antenna for Through-Wall Imaging (TWI) Systems

This paper presents an improved design of an Ultra-Wideband (UWB) Slotted Antipodal Vivaldi Antenna (SAVA) for through-wall imaging (TWI) systems. The antenna, featuring slots on both flares, is designed on a 1.58 mm thick Rogers 5880 material substrate and operates within the 3 GHz to 10 GHz range. The slots, both rectangular and circular, contribute to the improved performance of the antenna. Experimental testing of the fabricated antenna reveals a measured ∣S11∣ of less than or equal to -10 dB and a Voltage Standing Wave Ratio (VSWR) below 2. The antenna exhibits an improved radiation pattern and achieving maximum simulated gain of 11.7 dB within the operating range. The measured results align well with the simulated ones, thereby validating the design method. The proposed design, characterized by a compact aperture width, offers high gain, ultra-wide bandwidth, and directional radiation characteristics. These features make it suitable for TWI systems. This work contributes to the ongoing advancements in antenna design for imaging systems.