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一、前言近来,对于小口径抛物面天线的需求正在增长,特别是对商业通信和广播卫星接收的应用来说。现在都要求这类天线所用的馈源(初级辐射器)具有低旁瓣、低交叉极化及轴对称的辐射特性。在小直径的常规抛物面天线中,通常采用圆锥喇叭或开式(180°张角)波纹喇叭。但是,圆锥喇叭的辐射特性是基于圆形波导的传输模(一般是TE_(11)模),其E面和H面方向图有大范围的差异,因而用作抛物面天线馈源时,导致照射效率
I. Preface Recently, the demand for small aperture parabolic antennas is growing, especially for commercial communications and broadcast satellite reception applications. The sources (primary radiators) used for these antennas are now required to have low side lobe, low cross-polarization and axisymmetric radiation characteristics. In the small diameter of the conventional parabolic antenna, usually cone horn or open (180 ° angle) corrugated horn. However, the radiation characteristics of the conic horn are based on circular waveguide transmission modes (typically TE 11 modes) and have a wide range of E-plane and H-plane directional patterns, thus resulting in a parabolic antenna feed that causes illumination effectiveness