This book presents various design theories and methodologies for silicon-based high-sensitivity broadband receivers, including millimeter-wave radiometer chips and photoelectric receivers, which are core elements in imaging systems, data centers, and telecommunication infrastructures. As a key module in application systems, the high-sensitivity broadband receiver, not only attracts the attention of engineers and researchers in the radio-frequency and optoelectronic fields, but also garners significant interest from other disciplines, including optics, communications, and security. The book introduces various silicon-based critical design technologies aim to overcome the limitations inherent in silicon devices, distinctly enhancing sensitivity with a broad bandwidth. These innovative design methodologies, initially proposed and subsequently validated through meticulous measurements, represent a pioneering contribution. The book provides readers with detailed insights into design intricacies and considerations. Its audience includes undergraduate and graduate students with a specific interest in RF/optoelectronic receiver technology, along with researchers and engineers engaged in the study of imaging systems, data centers, or other communication applications.