Construction of a Small Compact Range for Satellite-Communication-Use Samll Planar Antenna Development

构建了用于测量12ghz小天线辐射方向图的3立方米小型消声室和面波源天线。首先，为了建立一个消声室，开发和测试了一些由泡沫聚苯乙烯板制成的吸收元件，这些板上有填充碳粉的圆锥形孔。然后，通过在墙壁上安装这些吸收器，就可以构建腔体。在f=12 GHz时，正入射腔壁反射系数小于-40 dB。源天线方面，对实验室自制的平面波导阵列天线（PWAA）进行了改进，提高了其性能。首先，为了减少PWAA和测试天线之间的相互作用，在PWAA表面加载2mm厚的吸收器（f=12 GHz时-20dB反射率）。其次，为了控制孔径分布，将2800个圆波导约束透镜以约束透镜面板的形式加载在PWAA表面上方约40 cm处。最后，为了减少由于相位/振幅调整而在受限透镜的输出处产生的交叉偏振分量的数量，并消除PWAA的边缘效应，在受限透镜表面的孔径上加载了一个由水平分层电阻膜和面板边缘吸收剂组成的泡沫聚苯乙烯面板。目前，为了扩大应用频率范围，计划将整个天线系统安装在旋转结构上。此外，供纸网络现在由共同供纸系统取代，从而改善了频率特性。

A small three-cubic-meter anechoic chamber and a plane-wave-generating source antenna for measuring 12-GHz-band small antenna radiation patterns have been constructed. First, in order to build in an anechoic chamber, a number of absorber elements made of foamed-polystyrene plates with circular conic holes filled with carbon powder are developed and tested. Then, by installing these absorbers on the wall, the chamber is constructed. The reflection coefficient of the chamber wall for normal incidence is smaller than -40 dB at f=12 GHz. As for the source antenna, a planar waveguide array antenna (PWAA) originally fabricated in our laboratory is modified and its performance is improved. First, in order to reduce interactions between the PWAA and test antennas, 2mm-thick absorbers (-20dB reflectivity at f=12 GHz) are loaded on to the surface of the PWAA.Next, for the purpose of controlling the aperture distribution, 2800 circular-waveguide constrained lenses in the form of a constrained-lens panel are loaded about 40 cm above the PWAA surface. Finally, to reduce the amount of cross-polarized components that are generated at the output of the constrained lenses as a result of the phase/amplitude adjustments and to remove edge effects from the PWAA, a foamed-polystyrene panel consisting of horizontally layered resistive films and absorbers at the panel edges are loaded on to the aperture of the constrained-lens surface. Presently, for the purpose of extending the frequency range of application, the whole antenna system is planned to be installed on a rotating structure. In addition, the feeding network is now replaced by a corporate feed system so that the frequency property is improved.