一种用于生命探测雷达的超宽带天线

摘要

An ultra-wideband planar antenna with a shallow cavity for the life detection radar is designed. The antenna is composed of a pair of semi-elliptical antenna arms and fed by a compact 1:2 unbalanced to balanced transmission line transformer. For the life detection radar working in pulse mode, large bandwidth and good time domain characteristics are key requirements to ensure the signal without distortion during the antenna design. In order to eliminate the reflections from the truncated edge on the antenna arm, one semicircle is digged out from the truncated edge, which improves effectively the absorption ability of the loaded resistors by forming two sharp tips at the end and enhancing the concentration of residual current on the antenna arm end. The simulated and measured results show that the designed antenna has good time domain characteristics and is suitable for the development and requirements of the life detection radar design.%该文设计了一种用于生命探测雷达的超宽带低背腔平面天线。该天线由一对半椭圆形天线臂组成，采用紧凑的1：2不平衡到平衡传输线变压器实现馈电。由于生命探测雷达工作在脉冲体制下，因而要求天线具有较大的带宽和良好的时域特性来保证信号不失真。为了消除天线臂截断效应引起的反射，采用半圆槽对天线臂末端进行锐化，增强了天线臂上残余电流的集中，同时采用电阻加载技术提高对反射电流的吸收能力。仿真和实验测量结果表明，所设计的天线具有良好的时域特性，能够满足生命探测雷达系统整机的开发和设计要求。