Timed Arrays

Introduces timed arrays and design approaches to meet the new high performance standards The author concentrates on any aspect of an antenna array that must be viewed from a time perspective. The first chapters briefly introduce antenna arrays and explain the difference between phased and timed arrays. Since timed arrays are designed for realistic time-varying signals and scenarios, the book also reviews wideband signals, baseband and passband RF signals, polarization and signal bandwidth. Other topics covered include time domain, mutual coupling, wideband elements, and dispersion. The author also presents a number of analog and digital beamforming networks for creating and manipulating beams. The book concludes with an overview of the methods to integrate time delay into the array design and of several other adaptive arrays that prove useful in many different systems. Examines RF signal concepts such as polarization and signal bandwidth and their applications to timed antenna arrays Covers arrays of point source, elements in timed antenna arrays, active electronically scanned array technology, and time delay in corporate fed arrays Includes complete design examples for placing time delay in arrays Timed Arrays: Wideband and Time Varying Antenna Arrays is written for practicing engineers and scientists in wireless communication, radar, and remote sensing as well as graduate students and professors interested in advanced antenna topics.

This book addresses the question how run-time reconfigurable constant multipliers (RCMs) can be efficiently implemented on field programmable gate arrays (FPGAs). RCMs calculate the multiplication of an input number by one out of several constants which can be selected during run-time. This is important as constant multiplication is an essential operation in digital signalprocessing (DSP) applications. The evaluation of RCMs is done by considering reconfiguration using reconfigurable look-up tables (LUTs),reconfiguration using multiplexers (MUXs) and Partial Reconfiguration (PR). This book contributes two new methods to generate RCMs using the first two reconfiguration principles. First, a LUT-based constant multiplier is extended to be reconfigurable. Second, optimized constant multipliers without reconfiguration are fused using MUXs. Moreover, a general post-optimization for MUX-based RCMs is proposed. Finally, the design space produced in this way is analyzed using synthesis experiments. The contributed methods provide important trade-off points in the design space of RCMs on FPGAs.

Specialized resource providing detailed coverage of recent advances in theory and applications of sparse arrays Sparse Arrays for Radar, Sonar, and Communications discusses various design approaches of sparse arrays, including those seeking to increase the corresponding one-dimensional and two-dimensional virtual array apertures, as well as others that configure the arrays based on solutions of constrained minimization problems. The latter includes statistical bounds and signal-to-interference and noise ratio; in this respect, the book utilizes the recent strides made in convex optimizations and machine learning for sparse array configurability in both fixed and dynamic environments. Similar ideas are presented for sparse array-waveform design. The book also discusses the role of sparse arrays in improving target detection and resolution in radar, improving channel capacity in massive MIMO, and improving underwater target localization in sonar. It covers different sparse array topologies, and provides various approaches that deliver the optimum and semi-optimum sparse array transceivers. . Edited by a world-leading expert in Radar and Signal Processing and contributed to by world-class researchers in their respective fields, Sparse Arrays for Radar, Sonar, and Communications covers topics including: Utilizing sparse arrays in emerging technologies and showing their offerings in various sensing and communications applications Applying sparse arrays to different environments and obtain superior performances over conventional uniform arrays Solving the localization, beamforming, and direction-finding problems using non-uniform array structures for narrowband and wideband signals Designing sparse array structures for both stationary and moving platforms that produce physical and synthesized array apertures. Using deep neural networks that learn the underlying complex nonlinear model and output the sparse array configuration using representations of the input data spatio-temporal observations Solving for optimum sparse array configurations and beamforming coefficients in sensing using iterative convex optimization methods Providing complete coverage of the recent considerable progress in sparse array design and configurations, Sparse Arrays for Radar, Sonar, and Communications is an essential resource on the subject for graduate students and engineers pursuing research and applications in the broad areas of active/passive sensing and communications.

Space-time array communications have gained a great deal of interest in recent years. Its superior performance in practical multipath propagation environments has established it as a core aspect in next generation mobile networks, as well as several portable wireless communication systems. In fact the employment of the sensor array component has already been provided for in the current UMTS standard, and there is presently a major thrust to make space-time processing an important part of 3G/4G networks. This book hence attempts to bridge the knowledge gap, looking at the integration of two emerging technologies from an array manifold perspective — space-time array processing and spread spectrum multiple access communications. It covers a range of novel multiuser channel estimation and reception techniques, which is designed to provide mitigations of the various associated channel impairments in accordance to its environmental context. For convenience of the readers, the book is written in a self-contained modular format with its mathematical frameworks and tools readily extendable to other research domains./a

The need to develop technology and communication necessitates the design of flexible and high-capacity radiating systems in today's communication infrastructure. In this context, antenna arrays are the ideal solution and have been one of the priority research subjects of the science community dealing with electromagnetics from past to present. Optimization of an array may be performed in various ways such as the optimization of excitation, reflector structure, feed network, etc. depending on the array structure. This book is a collection of seven research studies focused on the optimization of array structures in classical phased array or time modulation, including radiator, reflector, feed network, and radiating element optimizations.

Localization of transmitters and receiving sensors is achieved by measuring radiation emitted by a source to a set of sensors, which are either on a definite pattern, known as an array, or one randomly located at irregular points, known as a distributed sensor array. This book discusses how to determine the position of sensors and transmit information to a central node, also known as the anchor node. Time of arrival, time difference of arrival, frequency time of arrival, and strength of received signal are also covered. The reader will learn effective algorithms and implementation, as well as numerical examples, with the inclusion of lab experiments. It discusses time synchronization, including the rotating laser beam to measure distance, in detail.

A comprehensive guide that addresses the theory and practice of spatial audio This book provides readers with the principles and best practices in spatial audio signal processing. It describes how sound fields and their perceptual attributes are captured and analyzed within the time-frequency domain, how essential representation parameters are coded, and how such signals are efficiently reproduced for practical applications. The book is split into four parts starting with an overview of the fundamentals. It then goes on to explain the reproduction of spatial sound before offering an examination of signal-dependent spatial filtering. The book finishes with coverage of both current and future applications and the direction that spatial audio research is heading in. Parametric Time-frequency Domain Spatial Audio focuses on applications in entertainment audio, including music, home cinema, and gaming—covering the capturing and reproduction of spatial sound as well as its generation, transduction, representation, transmission, and perception. This book will teach readers the tools needed for such processing, and provides an overview to existing research. It also shows recent up-to-date projects and commercial applications built on top of the systems. Provides an in-depth presentation of the principles, past developments, state-of-the-art methods, and future research directions of spatial audio technologies Includes contributions from leading researchers in the field Offers MATLAB codes with selected chapters An advanced book aimed at readers who are capable of digesting mathematical expressions about digital signal processing and sound field analysis, Parametric Time-frequency Domain Spatial Audio is best suited for researchers in academia and in the audio industry.

A comprehensive tutorial on the design and practical applications of antenna arrays An antenna array is an assembly of antenna elements that maximizes a received or transmitted signal in a desired direction. This practical book covers a wide range of antenna array topics that are becoming increasingly important in wireless applications, with emphasis on array design, applications, and computer modeling. Each chapter in Antenna Arrays builds upon the previous chapter, progressively addressing more difficult material. Beginning with basic electromagnetics/antennas/antenna systems information, the book then deals with the analysis and synthesis of arrays of point sources and their associated array factors. It presents a sampling of different antenna elements that replace these point sources, then presents element configurations that do not have to lie along a line or in a plane. The complex and difficult-to-predict interactions of elements and electromagnetic waves are introduced, along with computer modeling and experiments that are necessary for predicting the performance of arrays where mutual coupling is important. Then, various approaches to getting signals to and from the array elements to a computer where the signal detection takes place are explored, as are the numerical techniques behind smart antennas. The book emphasizes the computational methods used in the design and analysis of array antennas. Also featured are signal processing and numerical modeling algorithms, as well as pictures of antenna arrays and components provided by industry and government sources, with explanations of how they operate. Fully course-tested, Antenna Arrays serves as a complete text in phased array design and theory for advanced undergraduate- and graduate-level courses in electronics and communications, as well as a reference for practicing engineers and scientists in wireless communications, radar, and remote sensing.