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 describes monopulse implemented with Active Electronically Scanned Arrays (AESAs). Both phase- and amplitude-comparison monopulse are addressed. Limitations imposed by AESAs and non-ideal performance due to quantization, vector modulator noise, and element failures are discussed. The author addresses monopulse using modern low-cost AESAs where the hardware is often non-ideal and where one must carefully balance cost and complexity. The relationship between AESA antenna gain and monopulse measurement is shown and is used to construct an accurate "first-principles" simulation of the monopulse measurement process including both Additive White Gaussian Noise and non-ideal hardware effects.For those unfamiliar with monopulse, this book discusses both the theory and implementation of monopulse for application in modern AESA antennas. For those familiar with the ideal performance of monopulse, the book shows the sensitivity of monopulse accuracy to non-ideal hardware implementations, particularly in AESAs. For those familiar with both, the book discusses Monte-Carlo techniques for simulating the measurement process to obtain realistic, non-ideal monopulse performance vs signal-to-noise ratio. And for those working in radar, the book explains the relationship between one-way monopulse and the monostatic radar case with two-way propagation utilizing the same antenna for both transmit and receive. Shows the relationship between monopulse theory and implementation in modern AESAs; Illustrates the relationship between AESA antenna gain and monopulse accuracy; Discusses the limitations of AESA hardware implementation on simultaneous sidelobe control and monopulse measurement.