Antennas in Matter provides both an introduction to and a comprehensive description of the properties of antennas and probes embedded within or near material bodies such as the earth, the ocean, or a living organism. The theory and application of antennas designed to transmit and receive information between points above the earth's surface are for the most part well understood. This book presents a full treatment of a sequence of research that has become increasingly important in recent years—the use of underground antennas for communication with miners and subway trains and for the geophysical exploration of the earth's crust; underwater antennas; antennas embedded in or near living organisms for biomedical and diagnostics in tissue and layered media with electromagnetic properties as diverse as those of fat, muscle, and bone. The book has been designed to serve a dual purpose: the first and third parts, covering fundamentals and measurements, form a self-contained introduction for undergraduates and researchers in geophysics and bioengineering; the second part provides a detailed presentation of the theory for graduate students and researchers in electrical engineering and physics. The approach integrates analytical, numerical, and experimental methods for the solution of a variety of problems involving antennas and electromagnetic wave propagation in or near matter.