Dipolar Model for Metamaterial Imaging Systems

We present a comprehensive simulation platform for computational microwave imaging systems based on frequency-diverse metasurface antennas (FDMAs). FDMAs consist of a waveguide patterned with complementary metamaterial elements with resonant frequencies selected randomly from a band of operation, enabling the generation of distinct frequency-indexed radiation patterns. By accurately modeling the fields produced by the FDMA using a dipolar model, it is possible to predict the capabilities of the imaging system in a fast and reliable manner. In contrast to previous works, in this paper we include the mutual interaction between metamaterial elements, and it is demonstrated that these interactions are crucial to a better understanding of the FDMAs' capabilities e. g. effective aperture area and correlation of radiation patterns. The simplicity and accuracy of the proposed model permits the simulation of different metasurfaces for computational microwave imaging, where traditional antenna design- and metamaterial modeling-are prohibitively costly.