移动通信中的双向圆极化微带天线的设计

Design on Bi-Directional Circularly Polarized Microstrip Antenna forMobile Communication

摘要: 本文设计了一种适用于狭长空间环境的双向圆极化微带天线。天线为双层结构的二元阵，下层为激励二元阵、上层为寄生二元阵，馈电点位于下层的几何中心。首先，利用切角的方式实现了圆极化，再通过近乎中心对称的电流分布实现了天线的双向辐射特性。在天线中心频率1.9 GHz上实现了夹角为72˚的双向圆极化辐射，相对阻抗带宽约为8.2%，最大辐射方向上相对轴比带宽(AR < 3dB)2.1%，增益约为5.7 dBi。

Abstract: A bi-directional and circularly polarized microstrip patch antenna is proposed for applications in the long corridor environment. This antenna consists of two substrate layers, in which binary- element patch array is at the bottom and parasitic binary element array is on top layer. It is center-fed from the bottom layer. Firstly, the circular polarization is achieved by means of truncating corners. Secondly, the bi-direction pattern is realized with the nearly symmetrical current distribution. A bi-directional radiation pattern has been achieved at the center-frequency of 1.9 GHz. The relative impedance bandwidth is about 8.2%, while the axial ratio bandwidth is about 2.1% at maximum radiation direction. The gain is about 5.7 dBi.