使用非均匀特异媒质覆层的高增益谐振腔天线

A resonant cavity antenna with a non-uniform metamaterial superstrate

采用非均匀特异媒质覆层,设计了一种具有高增益特性的新型谐振腔天线。该谐振腔天线采用矩形微带贴片天线作为辐射单元,安装在金属谐振腔内,其谐振频率为10 GHz。为提高天线增益,将腔表面安装蚀刻在微带基板上,由周期性单元组成特异媒质覆层。迥异于常规的单元尺寸均匀一致特异媒质覆层,本文研制的非均匀特异媒质覆层包含9×9个矩形单元,单元大小渐变。仿真表明,与常规均匀特异媒质覆层相比,该新颖的非均匀特异媒质覆层相当大程度提升了天线定向辐射性能:天线增益提高1.2 d B(从20.3 d Bi增加到21.5 d Bi),天线的旁瓣得到了抑制,主旁瓣比下降5 d B;同时,天线谐振频率和阻抗带宽等其他性能基本保持不变。

A Resonant Cavity Antenna(RCA) with a non-uniform metamaterial superstrate is proposed. A rectangular patch antenna, working at 10 GHz, is placed in a cavity as a primary source. A superstrate printed with square metal patches is placed in front of the antenna in order to increase the gain. Different from normal uniform metamaterial superstrate, the proposed structure consists of 9×9 units with different sizes. Simulation results demonstrate that the directivity of non-uniform metamaterial superstrate RCA increases by 1.2 d B(from 20.3 d Bi to 21.5 d Bi), and the side lobe is suppressed(the main-to-sidelobe ratio decreases by 5 d B), while the other properties like antenna resonant frequency and impedance bandwidth remain unchanged almost.