Reconfigurable fractional microwave signal processor based on a microcomb

TL;DR

This paper introduces a reconfigurable microwave signal processor using integrated Kerr microcombs, capable of fractional Hilbert transforms and differentiation with high resolution over 17 GHz bandwidth.

Contribution

It demonstrates a novel microcomb-based approach for reconfigurable microwave signal processing functions with high precision and broad bandwidth.

Findings

Achieved 45-degree phase shift for fractional Hilbert transform

Realized square-root differentiation as a fractional differentiator

Maintained phase deviation below 5 degrees over 17 GHz bandwidth

Abstract

We propose and demonstrate reconfigurable fractional microwave signal processing based on an integrated Kerr optical microcomb. We achieve two forms of microwave signal processing functions, a fractional Hilbert transform as well as a fractional differentiator. For the Hilbert transform we demonstrate a phase shift of 45 degrees, half that of a full Hilbert transform, while for the differentiator we achieve square-root differentiation. For both, we achieve high resolution over a broad bandwidth of 17 GHz with a phase deviation of less than 5 per degree within the achieved passband. This performance in both the frequency and time domains demonstrates the versatility and power of micro-combs as a basis for high performance microwave signal processing.