This book explains the principles and techniques of microwave physiological sensing and introduces fundamental results of the noninvasive sensing of physiological signatures, vital signs, as well as life detection. Specifically, noninvasive microwave techniques for contact, contactless, and remote sensing of circulatory and respiratory movements and physiological volume changes are discussed. , is written by a pioneering researcher in microwave noninvasive physiological sensing and leading global expert in microwaves in biology and medicine. The book reviews current advances in noninvasive cardiopulmonary sensing technology and measurement. It includes measurements of the vital signs and physiological signatures from laboratory and clinical testing. The book discusses the applicable domains and scenarios in which there is an interaction of radio frequency (RF) and microwaves with biological matter in gas, fluid, or solid form, both from inside and outside of the human or animal body. The book also provides examples for healthcare monitoring and diagnostic applications through wearables, devices, or remote contactless sensors for physiological signals and signature, vital signs, and body motion sensing. This book is an essential guide to understanding the human body’s interaction with microwaves and noninvasive physiological sensing and monitoring. This book is intended for researchers and professionals in biomedical, electrical, and computer engineering with an interest in antenna, sensors, microwaves, signal processing, and medical applications. It will also be of interest to healthcare professionals, technologists, and practitioners interested in noninvasive physiological sensing and patient monitoring.