An Upconverting Superheterodyne Metamaterial

A metamaterial capable of providing frequency conversion, through the use of a mixing effect, is presented. The metamaterial comprises of a square loop frequency selective surface (FSS) with embedded Schottky diodes, and a second layer which acts as a local oscillator for mixing purposes. An illuminating, plane wave, signal is converted to a number of high frequency harmonics providing an overall reduction, of the illuminating signal, of approximately 3dB. Numerical simulations are presented, along with prototype measurements which also demonstrate how the scattering pattern of the metamaterial can be modified due to the non-linear mixing effects.