改进型COBRA透镜天线的设计  

Design of improved COBRA lens antenna

作　　者：徐福锴[1] 周海京[1] 丁武[1] 

机构地区：[1]北京应用物理与计算数学研究所,北京100088

出　　处：《强激光与粒子束》2005年第8期1256-1258,共3页High Power Laser and Particle Beams

基　　金：国家863计划项目资助课题

摘　　要：设计了X波段COBRA透镜型天线,利用电磁波在不同介质传播速度的差异,通过放置于圆锥喇叭口径处不同厚度的介质透镜改变TM01模不同扇区的相位,从而改变TM01模在普通喇叭口径处的轴对称分布,将轴对称的口径场分布转换为线对称,进而实现线极化或圆极化的轴向辐射。通过添加匹配介质,减小介质对微波的反射和驻波特性的影响;延伸喇叭到透镜边缘,使移相过程在波导内完成,有效地控制了电磁场模式。天线增益在中心工作频率为9.3 GHz时为19 dB,口径效率25%,辐射效率大于90%,反射系数小于1.3,轴比小于2 dB,3 dB相对带宽大于30%,几乎可以覆盖整个X波段。An improved COBRA lens antenna in X-band for TMol mode is designed. The dielectric lens consisting of three or four sectors is located on the aperture plane of a conical horn. The antenna can radiate circular polarzied patterns, with a boresight peak and a high gain. The results of simulation demonstrate that at the operating frequency, the gain, the aperture efficiency and the radial efficiency are 19 dB, 25%, and more than 90% respectively. The axial ratio is less than 2 dB and the relative bandwidth of 3 dB is more than 30%, which covers almost the whole X-band.

关 键 词：TM01模 COBRA透镜天线 圆极化轴向辐射 

分 类 号：TN015[电子电信—物理电子学]