Phase Conjugation and Negative Refraction Using Nonlinear Active Metamaterials

TL;DR

This paper demonstrates experimentally that nonlinear active metamaterials with varactor-loaded split-ring resonators can produce phase conjugation and negative refraction, functioning as a compact RF lens that reverses signals.

Contribution

It introduces a novel active metamaterial design capable of phase conjugation and negative refraction, verified through experimental measurements.

Findings

Successful fabrication of nonlinear active metamaterial elements

Experimental confirmation of time-reversed signals

Demonstration of a sub-wavelength thick negative refraction lens

Abstract

We present experimental demonstration of phase conjugation using nonlinear metamaterial elements. Active split-ring resonators loaded with varactor diodes are demonstrated theoretically to act as phase-conjugating or time-reversing discrete elements when parametrically pumped and illuminated with appropriate frequencies. The metamaterial elements were fabricated and shown experimentally to produce a time reversed signal. Measurements confirm that a discrete array of phase-conjugating elements act as a negatively-refracting time reversal RF lens only 0.12$\lambda$ thick.