Ka波段双圆极化宽轴比波束小型化天线

Ka-band Miniaturized Dual Circularly Polarized Antenna with Wide Axial Ratio Beamwidth

摘要:

对 Ka 波段毫米波通信与卫星系统所需的宽角覆盖、双圆极化辐射天线进行了研究。采用顺序旋转馈电技术，设计了具有宽轴比波束特性的双圆极化小型化天线单元，并构建了 2×2 阵列天线，进行了仿真分析与实验测试。仿真结果表明，天线单元阻抗带宽（|S11|＜-10 dB）覆盖 19~31.2 GHz，相对带宽达 48.7%；3 dB 轴比带宽覆盖 20.2~28.8 GHz，相对带宽为 35.1%；26.5~28.5 GHz 频段内端口隔离度优于 15 dB，单元峰值增益达 6.67 dBi；在 27.5 GHz 频点，φ=0° 与 φ=90° 平面的 3 dB 轴比波束宽度分别可达 182.98° 与 203.49°，实现了宽角域圆极化覆盖。基于该单元的 2×2 顺序旋转阵列在 28.2~36 GHz 频段内 S11、S22与 S12均优于 - 10 dB，阵列增益范围为 8.55~11.30 dBi，左旋与右旋圆极化方向图对称性良好。该天线兼具小型化、宽波束与宽频带特性，满足了 Ka 波段毫米波通信与卫星接收领域的应用需求。

Abstract:

A wide-angle coverage, dual circularly polarized radiating antenna required for Ka-band millimeter-wave communication and satellite systems was investigated. Employing sequential rotation feeding technology, a miniaturized dual circularly polarized antenna element with wide axial-ratio beam characteristics was designed, and a 2×2 array antenna was constructed, followed by simulation analysis and experimental testing. Simulation results show that the impedance bandwidth (|S11| < ?10 dB) of the antenna element covers 19–31.2 GHz with a relative bandwidth of 48.7%; the 3 dB axial-ratio bandwidth covers 20.2–28.8 GHz with a relative bandwidth of 35.1%; the port isolation in the 26.5–28.5 GHz band is better than 15 dB, and the peak gain of the element reaches 6.67 dBi. At 27.5 GHz, the 3 dB axial-ratio beamwidths in the φ = 0° and φ = 90° planes reach 182.98° and 203.49°, respectively, achieving wide-angle circular polarization coverage. The 2×2 sequential rotation array based on this element exhibits S11, S22, and S12 all better than ?10 dB in the 28.2–36 GHz band, with an array gain ranging from 8.55 to 11.30 dBi and good symmetry between left-hand and right-hand circularly polarized radiation patterns. The antenna combines miniaturization, wide beam, and wide bandwidth characteristics, satisfying the application requirements of Ka-band millimeter-wave communication and satellite reception.