Electronically Scanned Arrays Esas And K Space Gain Formulation

This book fills in details that are often left out of modern books on the theory of antennas. The starting point is a discussion of some general principles that apply to all electronic systems and to antennas in particular. Just as time domain functions can be expanded in terms of sine waves using Fourier transforms, spatial domain functions can be expanded in terms of plane waves also using Fourier transforms, and K-space gain is the spatial Fourier transform of the aperture weighting function. Other topics discussed include the Discrete Fourier Transform (DFT) formulation of antenna gain and what is missing in this formulation, the effect of sky temperature on the often specified G/T ratio of antennas, sidelobe control using conventional and novel techniques, and ESA digital beamforming versus adaptive processing to limit interference. Presents content the author derived when first asked to evaluate the performance of an electronically scanned array under design with manufacturing imperfections and design limitations; Enables readers to understand the firm theoretical foundation of antenna gain even when they must start from well-known formulations rather than first principles; Explains in a straightforward manner the relationship between antenna gain and aperture area; Discusses the relationship between sidelobe control algorithms and aperture shape, how to take advantage of it, and what the penalties are; Shows the equivalence of Minimum-Variance, Distortionless Response (MVDR) and Space-Time Adaptive Processing (STAP) and how these algorithms can be used with ESA subarrays to mitigate interference.

This book fills in details that are often left out of modern books on the theory of antennas. The starting point is a discussion of some general principles that apply to all electronic systems and to antennas in particular. Just as time domain functions can be expanded in terms of sine waves using Fourier transforms, spatial domain functions can be expanded in terms of plane waves also using Fourier transforms, and K-space gain is the spatial Fourier transform of the aperture weighting function. Other topics discussed include the Discrete Fourier Transform (DFT) formulation of antenna gain and what is missing in this formulation, the effect of sky temperature on the often specified G/T ratio of antennas, sidelobe control using conventional and novel techniques, and ESA digital beamforming versus adaptive processing to limit interference. Presents content the author derived when first asked to evaluate the performance of an electronically scanned array under design with manufacturing imperfections and design limitations; Enables readers to understand the firm theoretical foundation of antenna gain even when they must start from well-known formulations rather than first principles; Explains in a straightforward manner the relationship between antenna gain and aperture area; Discusses the relationship between sidelobe control algorithms and aperture shape, how to take advantage of it, and what the penalties are; Shows the equivalence of Minimum-Variance, Distortionless Response (MVDR) and Space-Time Adaptive Processing (STAP) and how these algorithms can be used with ESA subarrays to mitigate interference.

Provides a compact but comprehensive treatment of the scanned array, from the underlying basis for array pattern behaviour to the engineering choices leading to successful design. The book describes the scanned array in terms of radiation from apertures and wire antennas and introduces the effects resulting directly from scanning.

"[Contains] more lengthy mathematical derivations than most {comparable books] ... for arrays, provides for a unique, stand-alone mathematical description that can be adopted by anyone trying to communicate the theoretical foundation for their array design...has insights from a practitioner that are unique. The MATLAB® scripts alone are worth the price." —Daniel C. Ross, Ph. D, Northrop Grumman Corporation Electronically Scanned Arrays: MATLAB® Modeling and Simulation is considered the first book to provide comprehensive modeling/simulation programs used to design and analyze Electronically Scanned Arrays (ESA), a key technology internationally in the scientific and engineering communities. Several books have been written about ESAs, but most cover only fundamental theory. Few, if any, provide the insightful, easy-to-use simulation tools found in this book. Obviously, MATLAB® is one of the greatest tools available for exploring and understanding science and engineering concepts, and we use MATLAB functions to easily and instantly calculate ESA patterns. However, to achieve a truly insightful and in-depth analysis of subarray architectures, conformal arrays, etc., it is imperative that users first develop a firm grasp of ESA fundamentals. Covers largely unexplored topics, such as reliability aspects and the application of ESAs in space This volume helps readers build that elemental understanding of how ESAs work. It also provides code to run as an aid, so that readers don’t have to start from scratch. The book expands on ESA principles and provides a modeling framework, using MATLAB to model applications of ESAs (i.e. pattern optimization, space-based applications, and reliability analysis). Presented code serves as an excellent vehicle to help readers master the analysis and simulation of ESAs. Exploring how difficult problems can be simplified with short, elegant solutions, this is an invaluable resource for students and others new to ESAs, as well as experienced practicing engineers who model ESAs at the systems level.

Electronic Scanned Array Design covers the fundamental principles of ESA antennas including basic design approaches and inherent design limitations. These insights enable better appreciation of existing and planned ESA systems including their application to earth observation. The material describes general design principles of aperture antennas applied to the specific case of ESA design.