This book reviews microwave and millimeter‐wave imaging techniques based on holographic principles. These techniques are used by the whole‐body imagers in the airports and other public places as part of routine security screening. Such devices exemplify the importance and practicality of the holographic image reconstruction techniques within a variety of other microwave imaging methodologies, most of which have been implemented in a controlled lab environments only. The book provides a condensed review targeting a broad audience including faculty, graduate students, and researchers working in the general area of microwave and millimeter‐wave imaging and sensing. The outline of the book is as follows:

In Chapter 1, a summary of the microwave imaging techniques and their applications is provided with a focus on the holographic imaging techniques.

Chapter 2 starts with the primary holographic imaging concepts developed in optics and then describes how these concepts were extended to microwave and millimeter‐wave imaging.

In Chapter 3, recent developments of wide‐band microwave holography with depth resolution are discussed. These developments are derived from holography techniques that utilize phase and amplitude information recorded over a two‐dimensional aperture to reconstruct a focused image of the object using computer algorithms emulating Fourier‐optics‐based image reconstruction. The evolution of these techniques from the synthetic aperture radar principles is also covered. Development of rectangular and cylindrical setups will be discussed together with their capabilities and their limitations.

Chapter 4 discusses the adaptation of these techniques to near‐field applications such as those arising in biomedical imaging, nondestructive testing, and underground imaging. These techniques utilize phase and amplitude information recorded over a two‐dimensional aperture and perform digital image reconstruction. However, they do not impose far‐field approximations on the waves (plane or spherical waves). Two recently developed approaches are utilized: (i) extracting near‐zone incident‐field and Green's function distributions, and (ii) using the measured point‐spread function of the imaging system.

Chapter 5 starts with introducing the well‐known “diffraction limit” in the resolution. Also discussed are some techniques to overcome this limit are discussed such as the use of super‐oscillatory filters and the use of resonant scatterers in the near‐field of the imaged objects. The chapter then discusses methods of obtaining quantitative images of the inspected medium.

In Chapter 6, the capabilities and limitations of the holographic reconstruction techniques discussed in the book are summarized. Also, recommendations are made to overcome some of these limitations and to expand the applications of the microwave/millimeter‐wave holographic techniques.

We are indebted to numerous colleagues and students who helped us develop the near‐field holographic imaging techniques. This book would not exist without their effort and we would like to acknowledge these people here: Prof. George Eleftheriades at the University of Toronto and a few graduate students at McMaster University including (in alphabetical order) Yona Baskharoun, Ali Khalatpour, Justin McCombe, Kaveh Moussakhani, Denys Shumakov, Daniel Tajik, Aastha Trehan, Sheng Tu, and Yifan Zhang. We would also like to thank Wiley‐IEEE Press for their encouragement and help while writing the book. Our deepest gratitude goes to our parents for their unwavering support during the many years of education and professional growth.