Software Defined Radio (SDR) is expected to be the solution for the integration between the several current wireless standards; it enables interaction between analogue and digital ports and links. This book provides a consolidated knowledge of new measurement systems and associated modeling strategies, including information from the analogue and digital domains, to aid the development of improved front end radio designs. The book explains the fundamental theory of SDR and how it relates to characterization and modeling. It presents the instrumentation used to characterize mixed-domain systems, and explores some of the strategies used in the modelling and characterization of those systems. These modelling and characterization approaches are then applied to some practical examples, before another chapter discusses the results of this system characterization in the presence of several excitation signals. Finally, a complete SDR system will be addressed and characterized using previous tools, allowing a thoughtful analysis of SDR systems. With this book, you will learn how to: Characterize SDR (mixed-domain) radio and wireless systems Employ different modeling strategies on RF hardware for SDR designs Execute measurement setups and extraction procedures for SDR characterization and modeling Comprehend the relevance and applicability of mixed-domain instrumentation and its calibration Understand the importance of analogue and digital integration for highly integrated radio designs.