Design of Lens based Focal Plane Arrays for Wide Field of View Imaging using Coherent Fourier Optics

In this abstract, a monotonically integrated lens based Focal Plane Array (FPA) is proposed for wide field of view (FoV) submillimetre imagers. The Coherent Fourier Optics method is used to represent the focal field of each lens element as a Plane Wave Spectrum (PWS) in reception. The FPA is then synthesized based on a field matching between this PWS and the radiation pattern of each feeder without employing any iterative optimization methods. The array achieved scan losses much lower than the ones of standard horn based FPAs: below 2dB while scanning up to ±20° with directivity of 52dB complying with the needs for future sub-millimetre security imagers. The technique is validated via full wave simulations with excellent agreement, and it is easily extendable to other wide FoV applications and scenarios.