Highly sensitive, broadband microwave frequency identification using a chip-based Brillouin optoelectronic oscillator.

Zihang Zhu,Steven J Madden,Benjamin J Eggleton,Khu Vu,Moritz Merklein,Duk-Yong Choi,Pan Ma

doi:10.1364/oe.27.012855

Abstract

Detection and frequency estimation of radio frequency (RF) signals are critical in modern RF systems, including wireless communication and radar. Photonic techniques have made huge progress in solving the problem imposed by the fundamental trade-off between detection range and accuracy. However, neither fiber-based nor integrated photonic RF signal detection and frequency estimation systems have achieved wide range and low error with high sensitivity simultaneously in a single system. In this paper, we demonstrate the first Brillouin opto-electronic oscillator (B-OEO) based on on-chip stimulated Brillouin scattering (SBS) to achieve RF signal detection. The broad tunability and narrowband amplification of on-chip SBS allow for the wide-range and high-accuracy detection. Feeding the unknown RF signal into the B-OEO cavity amplifies the signal which is matched with the oscillation mode to detect low-power RF signals. We are able to detect RF signals from 1.5 to 40 GHz with power levels as low as -67 dBm and a frequency accuracy of ± 3.4 MHz. This result paves the way to compact, fully integrated RF detection and channelization.

Highlights

With the rapid increase in the carrier frequency of transmitted radio frequency (RF) signals and the complexity of today’s electromagnetic environment, detecting and precisely estimating the frequency of RF signals over a broad frequency range and with high accuracy becomes more and more important for many applications, such as wireless communication [1], RF channelization [2], radio astronomy [3] and many more
3.2 Experimental results analysis First, two RF signals are injected into the Brillouin opto-electronic oscillator (B-optoelectronic oscillator (OEO)) cavity to demonstrate selective RF amplification
The theoretical mode spacing of the B-OEO loop is c/(nL), where c = 3 × 108 m/s is the speed of light in vacuum, n is the effective refractive index of the media, and L is the length of the B-OEO loop

Summary

Introduction

With the rapid increase in the carrier frequency of transmitted RF signals and the complexity of today’s electromagnetic environment, detecting and precisely estimating the frequency of RF signals over a broad frequency range and with high accuracy becomes more and more important for many applications, such as wireless communication [1], RF channelization [2], radio astronomy [3] and many more. Photonic RF signal detection and frequency estimation systems were based on fiber optics components [5,6,7,8] They have shown the potential for a broad frequency range using a Sagnac loop [5], a high detection sensitivity based on fiber Brag grating [6] or fiberbased SBS [7], and a low detection error based on amplified fiber-optic recirculating delay loop and broadband incoherent light source [8]. These optimum performances are obtained separately using different schemes and no single scheme has met all the performance requirements simultaneously. The sensitivity of this scheme is limited as the unknown RF signal that is to be measured is used to generate optical sidebands which act as the SBS pump

Results

Discussion

Conclusion