一种小型化平面螺旋天线的仿真设计

Design and Simulation of Miniaturized Planar Spiral Antenna

本文介绍了一种小型化阿基米德平面螺旋天线。首先对阿基米德螺旋臂进行正弦波纹调制,通过增加正弦波纹的幅度与周期数,有效的延长螺旋臂的周长,降低工作频率下限;接着采用终端集总电阻加载的方法,通过在螺旋臂上分段加载三个阻值90Ω的电阻,引导行波电流,同时吸收螺旋臂末端的反射电流,以改善低频段性能。该天线采用指数渐变微带巴伦馈电,背腔填充吸波材料实现单向辐射。仿真结果表明:该天线在2~12GHz范围内可实现VSWR<2,轴比小于3dB。

A miniaturized Archimedean planar spiral antenna is introduced in this paper. The miniaturization is realized by sine wave form extending of the spiral length and discrete resistance loading at the end of spiral.The amplitudes and cycles of sine wave are optimized to extend the low frequency limit. Three 90Ω resistors are added to each spiral to absorb the reflected current, therefore to improve the performance of the antenna at the low frequency. A antenna is achieved,integrated with a marchand balun and absorber filled cavity. Simulation shows that VSWR less than 2 and axial ratio less than 3 can be realized between 2 to 12 GHz.