宽带极化与方向图可重构天线研究

Wideband polarization and pattern reconfigurable antennas

随着无线通信系统的快速发展,宽带可重构天线将在未来发挥巨大作用.文中综述了四种宽带极化与方向图可重构天线,它们都具有提高通信系统容量,消除极化失配,扩大辐射范围等特点.首先介绍了一种宽带的多线极化可重构天线.此款天线基于L型探针馈电的贴片天线,实现了0°,45°,90°以及—45°极化的选择,具有宽带、低剖面、高增益的特点.其次,同样基于L型探针馈电的贴片天线,通过引入一个输出相位可重构的功分馈电网络,实现了宽带的圆极化可重构天线,其同样具有宽带、低剖面、高增益的特点.除了极化可重构天线,文中还介绍了两款方向图可重构天线,可分别实现线极化以及圆极化的全向锥状波束以及定向辐射波束的方向图可重构.前者是基于宽带的单极子贴片天线跟L型探针馈电的贴片天线的有机结合.后者是基于环缝隙的贴片天线配合激励端口可重构的功分馈电网络的组合.此两款天线均具有结构紧凑、宽带、增益稳定的特点.

The research on reconfigurable antennas becomes more and more popular recently along with the rapid development of modern wireless communication systems. Reconfigurable antennas will facilitate to increase the wireless channel capacity, to avoid polarization mismatch, and to enhance the radiation coverage. This paper will present four reconfigurable antenna designs that realize the wideband polarization and pattern reconfigurability. First, a wideband multi-linear polarizations reconfigurable antenna is introduced, that is based on the L-shaped probe fed patch radiators. Multiple L-shaped structure is adopted to realize the reconfigurability. Second, based on the same methodology, a wideband circular polarization reconfigurable antenna is developed via an output switchable power divider. Expect for the polarization reconfigurable antennas, this paper also presents two pattern reconfigurable antennas that achieve switchable conical-beam and broadside radiations. The former one utilizes the combination of a wideband monopolar patch antenna and an L-probe fed patch antenna. The latter one adopts an annular-slotted patch antenna fed by an excitation reconfigurable feed network. All the antennas discussed above exhibit wide bandwidth, low profile, stable realized gain and desired reconfigurability.