Merged Simulation Procedure for W-band Imaging Systems

This article presents and discusses a unifying simulation procedure aimed at providing more realistic performance prediction of basic imaging systems, combining 3D EM (3 Dimensions Electro-Magnetic) simulations and nonlinear receiver circuit simulation. New methods are proposed to emulate the radiated emissivity profile of a target body and to use harmonic balance simulation to emulate nonlinear circuit/system response to a broadband noisy stimulus. The procedure focuses mainly on passive imaging, but active imaging including illuminated passive imaging is dealt with and some elemental experiments are presented and discussed for comparisons. The method enables the extrapolation of the frequency response of a single pixel detector to an array with more elements suitable for providing a complete set of pixels and can help in evaluating the most suitable bandwidth according to the operation mode (passive/active), frequency range of operation, desired resolution, and the pixel number-image resolution tradeoff.