Broad-band phase-shifter based on stimulated Brillouin scattering and RF interference

Abstract

Phase shifters are an important building block of modern RF communications and RADAR systems, with an ever increasing demand to improve the operating bandwidth and to reduce power consumption and footprint. Microwave photonic phase shifters based on stimulated Brillion scattering (SBS) offer tunable and broadband phase shifts, however, their performance has been constrained by the requirement of high Brillouin gain to achieve 360° of phase shift. Here, we demonstrate a 360° broadband phase shifter by combining SBS and RF interference which greatly reduces the required Brillouin gain and thus the required optical power. Using this technique, we are able to enhance the phase shift by more than an order of magnitude, showing bandwidth tunability from 0.1-65 GHz while also being optimized to minimize amplitude variations. Show more