Design and measurement of quasi-optics for millimeter wave imaging system

Methods of designing quasi-optics are researched to improve the spatial resolution of the millimeter-wave imaging system. On the basis of characteristics comparison of different design methods and truncation effect considered, fundamental Gaussian beam method is used to design the quasi-optics. The relationship between waist radius and the gain of antenna is researched, and the lens as focusing element is designed together to meet the requirement of the system. Experimental results are given to illustrate the accuracy of the design method, and the reasons of the error are analyzed. The design process is easy to carry out while the result has good accuracy, so it is practical for designing the quasi-optics for millimeter wave imaging system.