Adapting mixer metamaterials with a metasurface absorber

This paper presents an in-depth study of mixer metasurfaces comprising a frequency-selective surface (FSS) mixer layer and a secondary transmission line local oscillator (LO) layer. Through both simulation and experimental measurement, we demonstrate how an upconverted signal is maximised by optimising metamaterial design and the separation of mixer components. Local oscillator signals at 2.1, 3, 4.2, and 4.45GHz were applied to the LO layer to drive the switching diodes on the mixer layer. The resulting metamaterial reflectivity, transmission, surface currents, scattering patterns, and 1D probe data were analysed, with results from a large-scale fabricated model verifying the simulations. Finally, the structure is augmented with a metamaterial absorber to suppress generated harmonics, demonstrating a novel multi-layered approach to incident signal manipulation and scattering control.