毫米波成像是近年来毫米波领域的一个研究热点，而焦面阵成像因其具有实时成像的优点更加受到重视。文中分析可用于焦面阵成像的扩展半球介质透镜。这种焦面阵成像结构将集成天线阵贴附在透镜背面接收透镜聚焦的功率，消除了集成天线工作在毫米波频段时存在的表面波对天线性能的影响，具有尺寸紧凑、损耗小的特点。采用Stmtton-Chu公式和射线追迹分析了电磁波人射到扩展半球透镜上时在其背面的场分布，即透镜的焦区场分布，以获得透镜用于焦面阵成像时的性能。为验证分析方法的正确性，对平面波垂直人射和会聚高斯束入射两种情形进行了实验验证，实验结果与理论分析吻合较好。该透镜天线还可用来消除常规集成毫米波系统中抛物面天线与集成前端之间的过渡，以降低损耗，改善系统性能，也可用于与准光系统的连接或耦合。该文结果将对上述应用提供理论指导。

Recently millimeter wave imaging absorbs many attentions. Especially much research work has been done on the millimeter focal imaging because of its advantage of real time imaging. This paper analyzes extended hemispherical lens, which can be used in focal imaging. An integrated antenna array is placed at the back plane of the lens to receive the power focused by the lens. This structure can eliminate the effect of the surface wave exited in the thick dielectric substrates at millimeter wave wavelengths. Low loss and compact are its merit. Assuming an electromagnetic wave is incident on the lens surface, the field distribution in focal space of the lens is analyzed by using Stratton-Chu formula and ray tracing method. It will provide much information about the imaging performance of the lens. Experiments have been carried out for two types of incident waves, one is normally incident plane wave and another is Gaussian-beam. Good agreement has been found between experiments and calculation results. The lens antenna also can be used to eliminate the transition between paraboloidal antenna and integrated front-end in conventional integrated millimeter wave systems so that the system loss can be decreased and performance can be improved. Furthermore, the lens can be used to couple with a quasi-optical system. The results presented here will provide useful guidelines for the above mentioned applications.