The Optical and RF Analysis of a Second Generation Integrated Optical Cancellation System

Abstract

With ubiquitous computing and the 'internet of things' increasingly becoming modern day realities, the demand for wireless communication links is exponentially increasing. With this increasing density of wireless communication links comes the issue of managing the physical communication channel, the RF spectrum. The balanced optical cancellation system (BOCS) analyzed in this thesis serves as a potential solution to drastically increase the spectral efficiency of modern wireless communications. The BOCS acts to cancel self-interference in transceiver systems, by utilizing knowledge of the nature of the unwanted self-interference signal.

The system presented here was designed in the Lightwave Communications Laboratory and produced by the Fraunhofer Heinrich Hertz Institute through the JePPIX MPW services. The BOCS was fabricated in the HHI06 fabrication run at JePPIX MPW alongside another cancellation system called MTAP.

This report describes the problem of self-interference and how cancellation can be performed. A brief outline of the overarching field of microwave photonics (MWP) is given to introduce the reader to the category of system the BOCS falls into. A review of previous work regarding photonics cancellation systems is provided to give context to the reader. A detailed overview of the system with explanation of the key benefits of the BOCS is followed by defining key performance metric and deriving their analytical expressions using system parameters. An analysis of the devices used in the BOCS is given through a series of experiments. This thesis concludes with an analysis of the overall performance of the BOCS, using experimental results and simulations.