新型多频蝶形微带天线

A novel multi-frequency butterfly microstrip antenna

微带天线工作频带较窄,若能同时激励多个谐振点,可以变相拓展带宽,因此设计一种多频蝶形微带天线。3块介质基板构成“U”型半封闭腔体,天线的辐射臂采用1 4周期正弦轮廓结构,在辐射臂上开取3对“工”字型缝隙,同时在馈电端口处加载枝节。实验结果表明,蝶形微带天线在5个雷达波段(S,C,X,Ku,K)各有1个谐振频点,分别为2.6 GHz,6.8 GHz,11.7 GHz,16.5 GHz,18.45 GHz。通过对比分析可知:在不改变天线整体尺寸的情况下,正弦边结构可调节谐振频点位置;加载的矩形枝节有利于改善天线的阻抗匹配度,降低回波损耗;“U”型半封闭腔体可有效提高增益,其中C波段的增益由0.71 dB可提升到4.30 dB。

The working band of microstrip antenna is narrow,which can be extended if multiple resonant points are excited simultaneously.Therefore,a multi-frequency butterfly microstrip antenna is designed,in which a U-shaped semi-closed cavity is constructed with three pieces of dielectric substrates,the structure with a quarter of cycle sine contour is used for the radiation arm of the antenna,three pairs of--shaped apertures are slotted on the radiation arm,and the dendritic matter is loaded at the feed port.The experimental result shows that the butterfly microstrip antenna has five resonant frequency points(2.6 GHz,6.8 GHz,11.7 GHz,16.5 GHz and 18.45 GHz)at five radar bands(S-band,C-band,X-band,Ku-band and K-band)respectively.The contrastive analysis results show that the sine side structure can regulate the location of resonant frequency point while maintaining the overall size of the antenna;the loaded rectangular dendritic matter is conducive to improving the impedance matching degree of the antenna,and reducing the return loss;the U-shaped semi-closed cavity can improve the gain effectively,especially the gain of C-band is increased from 0.71 dB to 4.30 dB.