Design of thin multilayer planar absorber for active millimeter-wave imaging system

Recently, a point-by-point active millimeter wave imaging system with shortened imaging time and reduced system cost and complexity is proposed. Demand for a mask to shape transceiver beam arises accordingly. Absorbing materials plays a critical role for the mask. Design of thin multilayer planar absorber in this paper. Differential evolution (DE) algorithm is implemented to solve the equivalent multi-dimensional nonlinear optimization problem. Three absorbers of less than 0.3 mm have been synthesized with at least 14 dB absorption from 0° to 30°, at 96 GHz.