A Tutorial on Microwave Photonics

The broad bandwidth and low loss offered by modern photonics have led to an ever-increasing interest in the design and implementation of photonically assisted solutions for the generation, processing, control and distribution of microwave signals, an area called microwave photonics. In this article, a tutorial on microwave photonics is presented with an emphasis on optical generation of microwave signals and alloptical microwave signal processing. Introduction Microwave photonics is an area that studies the interaction between microwave and optical waves for application such as radar, communications, sensor networks, warfare systems and instrumentation. In the past few years, there has been an increasing effort in researching new microwave photonic solutions for these applications [1]. In general, the microwave photonics techniques cover the following topics: 1) photonic generation of microwave signals, 2) photonic processing of microwave signals, 3) photonic distribution of microwave signals, and 4) photonic analog-to-digital conversion. In this article, techniques developed in the last few years are reviewed with an emphasis on the system architectures to implement the functions for the photonic generation, and processing of microwave signals. Optical Generation of Microwave Signals A high frequency and frequency-tunable microwave signal can be generated by beating two optical waves at a photodetector (PD), as shown in Fig.1. Assume we have two optical waves