一种新型圆极化法向模反转螺旋天线

针对于传统圆极化法向模螺旋天线输入阻抗低、增益小等问题,设计了一种新型反转结构的螺旋天线。该天线采用了反转结构,即在电流反向点处使螺旋物理结构反向,实现天线辐射能力增强,提高天线在工作频率处的辐射电阻,增大阻抗带宽和增益。研究结果显示,一次反转螺旋天线仿真增益达2.45 dBi;两次反转螺旋天线加上巴伦后仿真增益达2.72 dBi,仿真阻抗带宽为2.9%,相应测试结果分别为2.5 dBi和2.8%。需要指出的是,随着反转次数的增多,天线的辐射电阻和增益可以进一步提高,因此可根据不同的设计需求选择不同反转次数。另外,采用3D打印技术加工螺旋,可以有效降低天线加工难度。

A new circularly-polarized normal-mode reverse-rotation helical antenna

In order to solve the problems of low input impedance and gain of traditional omnidirectional circular polarization(OCP)normal-mode helical antennas,a new reverse-rotation helical antenna with OCP radiation was designed.The surface current was reversed at the connection point of adjacent helixes.Thus,the horizontal current component of all helical segments were enhanced.The simulated results show that the gain of a one-time reverse-rotation helix model can be up to 2.45 dBi.The simulated gain and impedance bandwidth of a two-time reverse-rotation helix with balun are 2.72 dBi and 2.9%,respectively.While the measured results are 2.5 dBi and 2.8%,respectively.It should be mentioned that different number of segments of the antenna can be selected based on the requirements of application.