Subwavelength position sensing using nonlinear feedback and wave chaos

TL;DR

This paper introduces a novel subwavelength position sensing method leveraging wave chaos and nonlinear feedback, achieving extremely high resolution by analyzing frequency changes in a complex RF field.

Contribution

The work demonstrates a new technique for subwavelength position sensing using wave chaos and nonlinear feedback, with unprecedented resolution capabilities.

Findings

Achieved ~λ/10,000 resolution in one dimension

Achieved ~λ/300 resolution in two dimensions

Utilized frequency analysis of feedback signals for position detection

Abstract

We demonstrate a position-sensing technique that relies on the inherent sensitivity of chaos, where we illuminate a subwavelength object with a complex structured radio-frequency field generated using wave chaos and a nonlinear feedback loop. We operate the system in a quasi-periodic state and analyze changes in the frequency content of the scalar voltage signal in the feedback loop. This allows us to extract the object's position with a one-dimensional resolution of ~\lambda/10,000 and a two-dimensional resolution of ~\lambda/300, where \lambda\ is the shortest wavelength of the illuminating source.