Modeling Focused CW Mm-Wave Scattering of a Penetrable Dielectric Slab Affixed to a Human Body

Predictive 3D mm-wave nearfield radar modeling requires challenging tradeoffs between computational size and accuracy. For raster-scanned focused spot antenna systems, both the focusing array antenna and the target region must be finely and fully sampled, but the intervening space is large, making the computational space huge. For focusing along the axis in target geometries with only material variation in range, it is possible to scale the transmitter/receiver array and its range to target by a factor of two or four. But for even small amounts of off-axis focusing, the scaling must be done with care to avoid specular reflected rays that might miss the scaled transceiver array. Simulations based on ray analysis, analytic arrays of dipoles, and Quasi-Axisymmetric Finite Difference Frequency Domain (QAFDFD) compare well with each other. Only QAFDFD, however, can model target edge effects in the presence of large ground planes.