Design and Investigation on Antipodal Vivaldi Antenna Emitting a Pulse-Like Waveform for Imaging Close-Range Objects

Abstract

This paper presents the design methodology for an antipodal Vivaldi antenna (AVA) catered to emit an impulse-like waveform, relevant for near-field imaging in impulse-radio ultra-wideband (IR-UWB) radar systems. The focus of the proposed design is to optimize the pulse response from a time-domain perspective. We have examined the radiator parameters that influence the evaluation factor, a new proposed key metric for assessing short pulse radiation performance. We show that the evaluation factor lead us to a better design of the AVA. The VSWR is below 2 from 1.8 to more than 10 GHz, which has a 5:1 bandwidth characteristic. The wireless functionality of two optimized identical antennas of AVAs is tested with antenna’s transfer function, received pulse, group delay, and realized gain for three different orientation configurations up to 10 GHz. An indoor pulse radar experiment using a synthesized aperture length was conducted to capture a radar target image. Utilizing the optimized AVA, two radar targets placed 7 cm apart are accurately reconstructed. The developed optimized AVA is an excellent candidate for close-range area sensing and imaging applications.

Keywords

• Antipodal Vivaldi antenna
• impulse-radio ultra-wideband (IR-UWB)
• pulsed radar antenna
• radar imaging