Equivalent optical design of the bifocal lens antenna in passive millimeter imaging system

Focal plane imaging is the most commonly used modality in passive millimeter imaging (PMI) system design. This paper described a multi-channel focal plane array which composed of dielectric focal lens and dielectric tapered slot rod array so that the field of view can be scanned simultaneously. Some simplification and approximation are undertaken in order to easy design and machining, meanwhile, the engineering requirements can be well satisfied yet. And an equivalent optical design method combined with finite element method (FEM) of the HFSS and physical optics method (PO) of FEKO is provided to solve the large scale electromagnetic simulation problem in lens antenna. The simulation results are presented to confirm the success of this design method.