Hilbert Transform based Quadrature Hybrid RF Photonic Coupler via a Micro-Resonator Optical Frequency Comb Source

TL;DR

This paper presents a broadband photonic RF Hilbert transformer using an integrated optical frequency comb from a microring resonator, achieving wide bandwidth and uniform phase response for microwave signal processing.

Contribution

It introduces a novel photonic RF quadrature filter based on a CMOS-compatible microring resonator generated optical comb, enabling high-tap filters with broad bandwidth.

Findings

Achieved a quadrature filter with over 5-octave bandwidth

Demonstrated a filter with up to 20 taps

Realized almost uniform phase response across the bandwidth

Abstract

We demonstrate a photonic RF Hilbert transformer for broadband microwave in-phase and quadrature-phase generation based on an integrated frequency optical comb, generated using a nonlinear microring resonator based on a CMOS compatible, high-index contrast, doped-silica glass platform. The high quality and large frequency spacing of the comb enables filters with up to 20 taps, allowing us to demonstrate a quadrature filter with more than a 5-octave (3 dB) bandwidth and an almost uniform phase response.