微带巴伦馈电圆锥正弦天线设计与实验

Design and experiments of the conical sinuous antenna fed by microstrip Balun

以双极化被动雷达为应用背景,开展了圆锥正弦天线的结构设计与实验方面的研究。圆锥正弦天线是将平面型四臂正弦天线设计成与圆锥表面共形的形式,采用微带粘结法加工而成。引入两个微带指数渐变平衡-不平衡转换器(巴伦)实现对四臂圆锥正弦天线的平衡馈电。针对频率2～5GHz的范围,设计了具体的天线结构和微带巴伦,对实际加工的天线进行了实际测量工作。在工作频率范围内,测得的两个极化端口的输入平均电压驻波比(VSWR)约为2,增益均大于4dBi,极化端口隔离度约低于-20dB,辐射方向图具有较好的极化纯度。本文的研究成果对实际工程具有重要的参考价值。

The structure design and experiments of the conical sinuous antenna for the dual polarized passive radar application are researched. The planar sinuous antenna with four arms was designed to be conformal with the surface of the cone and the conical sinuous antenna was fabricated through microstrip adhering technique. The conical sinuous antenna with four arms was fed in balanced mode by two microstrip exponentially tapered balanced-to-unbalanced transformers （Balun）. The specific antenna structure and microstrip Balun were designed within the frequency range from 2 GHz to 5 GHz. The fabricated antenna was measured. Over the operating frequency range, the measured average input voltage standing wave ratio （VSWR） is about 2; the measured gain of each port is higher than 4 dBi, the meas- ured isolation degree between two ports is about less than -20 dB and the radiation pattern has good polarization purity. The research results provide references for practical engineering application.