Substrate Integrated Waveguide (SIW) has evolved over the last decade as a promising technology to realize low-cost and convenient microwave and mm-wave systems with interesting performance characteristics. With the design of SIW-based systems there is a requirement to look for certain aspects in terms of performance, feasibility and readiness for commercial use cases. Substrate Integrated Waveguides thoroughly outlines the working principle, design rules and fabrication procedures of SIW, and several novel design concepts for implementing antennas and passive and active circuits using SIW technology. It focuses on using substrate-A-integrated waveguides for designing antennas, antenna arrays, filters and other parts of a modern transceiver. Substrate Integrated Waveguide is an important technology for 5G applications and beyond.Readers will gain a deep understanding of how to leverage SIW for developing advanced microwave and millimeter-wave systems. The book's coverage extends from basic communication principles to the intricate design of SIW-based circuits and systems, ensuring that the reader is equipped with the necessary knowledge to innovate in this rapidly evolving field.Targeted at RF engineers, academic researchers, and post-graduate students, this book stands out by offering a holistic perspective on SIW technology. It goes beyond just the basics, integrating both theoretical foundations and practical design approaches. This book serves as an essential resource for those seeking to master SIW technology. Whether for academic study or practical application, it provides the tools and insights necessary to contribute to the next generation of communication systems, particularly in terms of 5G and future technologies.