分布电阻加载平面蝶形偶极天线的辐射特性分析

Study about the Radiation Properties of Bow-Tie Antennas with Distributed Resistor-Loaded

天线是探地雷达系统的重要组成部分,它将直接影响整个系统的性能。平面蝶形天线是探地雷达中采用最多的天线形式之一,但标准蝶形天线辐射波形仍存在振荡且辐射特性受地面影响。本文给出了一种新型的分布电阻加载平面蝶形天线,并通过FDTD法分析了该天线位于近地表面时的辐射波形、输入阻抗和方向性等辐射特性。结果表明,与标准蝶形天线相比,该天线具有更好的时域波形和响应特性。最后,还分析了屏蔽腔和吸收材料对天线辐射波形和方向性的影响。

The antenna is the critical component of the ground penetrating radar （GPR） system, and it usually determines the performance of systems. The bow-tie antenna is one of common antennas used in GPR. But the radiation waveforms of the conventional bow-tie antennas have oscillation and depend on the operating environment. In this paper, a bow-tie antenna with distributed resistor-loaded is presented. Input impedances, radiated waveforms, and energy radiation patterns of resistor-loaded bow-tie antenna are researched using the finite difference time domain （FDTD） method when the antenna is located above the earth＇s surface. The simulation results show that the time domain response and radiation waveform of bow-tie antennas with distributing resistively loaded are better than conventional bow-tie. At last, the influence of the shields and absorbers on the radiation waveforms and patterns is studied.