基于共形馈电网络的新型双频四臂螺旋天线

针对卫星地面手持终端系统对天线高效率宽波瓣的应用要求,文章提出一种新型双频印刷一体化四臂螺旋天线结构,通过两种方式提高其双频辐射效率:第一,每组辐射振子分成两个支路,分别以不同的长度、宽度和螺旋角度绕制以减少振子间耦合,同时覆盖两个不同的频点;第二,馈电网络和辐射振子进行一体化设计,提高其馈电效率。测试结果表明:在两个间距很近的频点(1.1倍频程)能够分别实现4.3dBi(低频)和4.2dBi(高频)的右旋圆极化增益,且4dBi以上右旋圆极化增益相对频带宽度分别为6%(低频)和5%(高频),圆极化3dB波瓣宽度均达到130°以上。该天线的双频点、宽波束、高效率性能适合于卫星通信手持终端系统应用。

A Novel Dual-Frequency Printed Quadrifilar Helical Antenna Based on Conformal Feed-Network

A novel printed dual-band octafilar helical antenna operational at two frequcecies is presented for satellite mobile communication systems in this paper. Two ways be used to improve radiation efficiency. Frist, four bifilar which is consists of two helices of different lengths, widths and picth angles raditors formed two resonant frequencies and reduced the mutual coupling. Second, integration design be used to feed network and radiation vibrator, and radiation efficience is improved. Experimental results show that 4. 3dBi circular polarisation gain is achieved at the low frequency with 6% bandwith (gain>4. 0dBi) and 4. 2dBi at the high frequency with 5% bandwith (gain>4. 0dBi),130° 3dB beamwidth is achieved at both low and high frequency. The proposed antenna displays several attractive characteristics for satellite mobile communication systems applications such as duel-frequency, hemispherical pattern, high radiation-efficiency.