Compact Dual-polarized UWB Antenna for UAV Based Low-Frequency Software Defined Radar

A dual-polarized ultrawideband antenna for a software-defined radar (SDRadar) mounted on an unmanned aerial vehicle (UAV) with various modes of operations is proposed. The antenna consists of two perpendicularly combined double slot Vivaldi antennas (DSVA) to achieve a reasonable gain over a wide bandwidth and is compact enough to meet the UAV payload size requirement. An antenna operating in the range of 0.25 − 2.5 GHz is designed and ready for fabrication. The simulated reflection coefficients of the antenna is shown to be better than −10 dB within the design frequency range. The antenna is low-profile with a total height of 300 mm and lateral dimensions of 230 mm × 230 mm. This design allows the radar system to operate in multiple modes, including ground penetrating sounding and imaging modes. This article details the design process and simulated results for the DSVA antenna element of the dual-polarized antenna.