Abstract
In this paper, we report a complete design and simulation of a quasi-optical millimeter wave imaging system using ZEMAX and FEKO software, respectively. A Fresnel lens and a horn antenna are combined in this this design. Compared to spherical and aspherical lenses, a Fresnel lens can be fabricated much easier at millimeter wavelengths. For focusing millimeter wave radiation, a Fresnel lens can be used to reduce the thickness of the focusing element and to lighten its weight from 25 Kg to 4.5 Kg. A horn antenna with a Gaussian profile and corrugated walls is designed for feeding this system at a central frequency of 94 GHz. The symmetrical radiation pattern of the designed corrugated Gaussian horn in E and H orthogonal planes, its wide bandwidth and low side lobe levels make it a good candidate for feeding a W-band millimeter wave imaging system. The designed quasi-optical imaging system is light-weighted, has high resolution and can be used in detecting hidden objects within a distance of 5 meters with a 30 mm resolution in W-band at a central frequency of 94 GHz.
Quasi-Optical Design of a Millimeter Wave Imaging System
