L波段全向天线研究与设计

在实际应用中，有时需要全向天线在水平面以上覆盖较广的空域，针对这一需求，文章提出了两种工作在L频段的波束上翘的全向天线。其中一种为使用同轴转平行双线结构进行馈电的串联印刷偶极子天线，且加入反射板保证波束上翘，实测结果表明该天线在工作频段内，电压驻波比(voltage stanting wave ratio,VSWR)小于1.5，水平面增益大于2dBi，俯仰角0°~70°(定义水平方向为0°)增益大于-7dBi，不圆度小于2dB。另一种为双锥天线，使用上下锥体不对称结构保证波束上翘，同时引入固定套环保证天线的稳定性。实测结果表明该天线在工作频段内，VSWR小于2，俯仰角0°~20°增益大于1dBi，俯仰角0°~70°增益大于-7dBi，不圆度小于2.5dB。该天线结构稳定，性能优良，可应用于车载通信或其他通信场景中。

Research and design of L-band omnidirectional antennas

In practical applications, omni-directional antennas are sometimes required to cover a wide range of airspace above the horizontal plane. In order to meet this demand, two kinds of omni-directional antennas working in the L-band beam are proposed in this paper. One of them is a series printed dipole antenna fed by a coaxial-to-parallel double-wire structure, and a reflector is added to ensure that the beam is warped. The measured results show that in the working frequency band, the voltage standing wave ratio is less than 1.5, the horizontal plane gain is greater than 2dBi, the pitch angle 0°~70° (defined horizontal direction is 0°) gain is greater than -7dBi, and the out-of-roundness is less than 2dB. The other is the biconical antenna, which uses the upper and lower cone asymmetry structure to ensure the up warping of the beam, and introduces a fixed ring to ensure the stability of the antenna. The measured results show that in the working frequency band, the voltage standing wave ratio is less than 2, the pitch angle 0°~20° gain is greater than 1dBi, the pitch angle 0°~70° gain is greater than -7dBi, and the out-of-roundness is less than 25dB. The antenna has stable structure and excellent performance, and can be used in vehicle communication or other communication scenarios.