This book offers an in-depth exploration of the latest advancements in high-speed electronics and optoelectronics, focusing on breakthrough technologies that drive faster data rates, lower power consumption, and improved system performance. Readers gain insights into advanced materials like graphene and black phosphorus, cutting-edge device architectures, and innovative circuit designs for gigahertz (GHz) and terahertz (THz) frequencies. With practical research and real-world applications, this book greatly benefits postgraduate students, academic researchers, and professionals working in telecommunications, photonics, and next-generation electronics systems.