Improvement of Bow-Tie Antenna for Ground Penetrating Radar

A novel bow-tie antenna for 400 MHz ground penetrating radar (GPR) is proposed in this paper. Different from the conventional bow-tie antennal, one semicircular structure is added to each of the radiation arm. Simulation results show that a relative bandwidth of 100% can be achieved with the operation frequency ranging from 200 MHz to 600 MHz, indicating a 16% increased bandwidth compared with the normal shaped bow-tie antenna. In addition, with stable radiation pattern, the size of the proposed antenna ( 343 mm×192 mm) is 22% smaller than normal structure. It is proved that the proposed antenna is feasible for GPR.

I. Introduction

The ground penetrating radar (GPR) system is applied to detect underground matter based on the radio wave. The microwave signal produced by the transmitting antenna is reflected by the medium with different electrical properties when propagating in the underground. The reflected microwave is captured by the receiving antenna. By analyzing the characteristics of the reflected signal, such as the waveform, amplitude, time-varying feature and so on, inference can be made to obtain the location, structural form and characteristic, buried depth of the underground medium [1].