Design of exponential gradient TEM horn antenna for ground penetrating radar

Abstract

Ground Penetrating Radar (GPR) technology is a kind of Ultra-wideband technology for underground targets. In this paper, an ultra-wideband transverse electromagnetic wave (TEM) horn antenna is designed. The size of this antenna is effectively reduced by adopting an exponentially graded horn structure, composite loading. Adding a metal reflector near the feeder further improves the antenna radiation directivity. The simulation results show that the designed antenna size is 0.50m×0.49m×0.33m (0.21×0.20×0.13λ). In the range of 0.125~3.1GHz, the voltage standing wave ratio is below 2, and the bandwidth ratio is 24.8:1. The gain is higher than 11.2dB above 1GHz.