50-100 Ohms, 130MHz-5GHz Resistively Loaded Bow-tie Antenna for Efficient UWB mono-Pulse Radiation

Abstract In this paper, a novel mono-pulse radiator bow-tie antenna for high-resolution Ground Penetrating Radar (GPR) is introduced. First, an analysis is provided to reveal the effects of low frequency components on late time ringing (LTR) and pulse distortion. Then, a loading methodology is proposed that offers alleviated power attenuation based on the equivalent circuit model (ECM) analysis. The antenna is configurated for providing the conventional bowtie structures with more effective surface and traveling waves, simultaneously. To suppress the intrinsic impedance oscillations, a limited number of resistive loads are embedded in the structure. A Nonuniform weighing technique is utilized through optimization process to reinforce the essential low frequency coverage and to reduce LTR. The antenna shows an ultra-wideband 38:1 impedance bandwidth, ranging from 130 MHz to 5 GHz, a maximum gain of 8-20 dB, as well as a very low pulse distortion compared to the conventional designs. Shielding effects are also analyzed. Finally, experimental data are provided to validate the obtained performance.