Scattering Cross Section Of Unequal Length Dipole Arrays

This book presents a detailed and systematic analytical treatment of scattering by an arbitrary dipole array configuration with unequal-length dipoles, different inter-element spacing and load impedance. It provides a physical interpretation of the scattering phenomena within the phased array system. The antenna radar cross section (RCS) depends on the field scattered by the antenna towards the receiver. It has two components, viz. structural RCS and antenna mode RCS. The latter component dominates the former, especially if the antenna is mounted on a low observable platform. The reduction in the scattering due to the presence of antennas on the surface is one of the concerns towards stealth technology. In order to achieve this objective, a detailed and accurate analysis of antenna mode scattering is required. In practical phased array, one cannot ignore the finite dimensions of antenna elements, coupling effect and the role of feed network while estimating the antenna RCS. This book presents the RCS estimation of an array with unequal-length dipoles. The signal reflections within the antenna system and the mutual coupling effect are considered to arrive at the total RCS for series and parallel feed. The computations are valid for any arbitrary array configurations, including side-by-side arrangement, parallel-in-echelon, etc.

In this book, the RCS of a parallel-fed linear and planar dipole array is derived using an approximate method. The signal propagation within the phased array system determines the radar cross section (RCS) of phased array. The reflection and transmission coefficients for a signal at different levels of the phased-in scattering array system depend on the impedance mismatch and the design parameters. Moreover the mutual coupling effect in between the antenna elements is an important factor. A phased array system comprises of radiating elements followed by phase shifters, couplers, and terminating load impedance. These components lead to respective impedances towards the incoming signal that travels through them before reaching receive port of the array system. In this book, the RCS is approximated in terms of array factor, neglecting the phase terms. The mutual coupling effect is taken into account. The dependence of the RCS pattern on the design parameters is analyzed. The approximate model is established as an efficient method for RCS estimation of phased arrays. This book presents a detailed formulation of approximate method to determine RCS of phased arrays, which is explained using schematics and illustrations. This book should help the reader understand the impinging signal path and its reflections/transmissions within the phased array system.

This book discusses the active and passive radar cross section (RCS) estimation and techniques to examine the low observable aerospace platforms. It begins with the fundamentals of RCS, followed by the dielectric, magnetic and metamaterials parameters of the constituent materials and then explains various methods and the emerging trends followed in this area of study. The RCS estimation of phased array including the mutual coupling effect is also presented in detail in the book. The active RCS reduction is carefully touched upon through the performance of phased arrays, sidelobe cancellers and mitigation of multipath effect. Providing information on various adaptive algorithms like least mean square (LMS), recursive least square (RLS) and weighted least square algorithms, the authors also mention the recent developments in the area of embedded antennas, conformal load bearing antenna, metamaterials and frequency selective surface (FSS) based RCS reduction.

An in-depth treatment of array phenomena and all aspects of phased array analysis and design Phased Array Antennas, Second Edition is a comprehensive reference on the vastly evolving field of array antennas. The Second Edition continues to provide an in-depth evaluation of array phenomena with a new emphasis on developments that have occurred in the field over the past decade. The book offers the same detailed coverage of all practical and theoretical aspects of phased arrays as the first edition, but it now includes: New chapters on array-fed reflector antennas; connected arrays; and reflect arrays and retrodirective arrays Brand-new coverage of artificial magnetic conductors, and Bode matching limitations A clear explanation of the common misunderstanding of scan element pattern measurement, along with appropriate equations In-depth coverage of finite array Gibbsian models, photonic feeding and time delay, waveguide simulators, and beam orthogonality The book is complemented with a multitude of original curves and tables that illustrate how particular behaviors were derived from the author's hundreds of programs developed over the past forty years. Additionally, numerous computer design algorithms and numerical tips are included throughout the book to help aid in readers' comprehension. Phased Array Antennas, Second Edition is an ideal resource for antenna design engineers, radar engineers, PCS engineers, and communications engineers, or any professional who works to develop radar and telecommunications systems. It also serves as a valuable textbook for courses in phased array design and theory at the upper-undergraduate and graduate levels.

This book presents the detailed analytical formulation for the RCS of parallel-fed linear dipole array in the presence of mutual coupling. The radar cross section (RCS) of an object represents its electromagnetic (EM) scattering properties for a given incident wave. The analysis of scattered field is critical in military and defence arenas, especially while designing low-observable platforms. It is well-known that the presence of an antenna/array on the target influences its echo area significantly. The primary cause for such scattering of the incident signals is reflection that occurs within the antenna aperture and its feed network. In this book, the RCS estimation is done based on the signal path within the antenna system. The scattered field is expressed in terms of array design parameters including the reflection and transmission coefficients. The computed results show the variation in the RCS pattern with and without mutual coupling. The effect of finite dipole-length, inter-element spacing, scan angle, array configuration, amplitude distribution and terminating load impedance on the RCS pattern is studied. It is shown that the array RCS can be controlled by choosing optimum design parameters, including terminating impedance and geometric configuration. This book explains each step of the RCS estimation and analysis of dipole array with detailed schematics, tables and illustrations. Moreover, it includes parametric analysis of RCS estimation and control. This book provides an insight into the phenomenon of scattering within the phased array system.

A periodic surface is an assembly of identical elements arranged in a one or two-dimensional array. Such surfaces have various effects on incident electromagnetic waves. Their applications range from antennas to stealth aircraft.This book discusses finite antenna arrays and how to minimize the radar cross section of these arrays. "Ben has been the world-wide guru of this technology...Ben Munk has written a book that represents the epitomy of practical understanding." W. Bahret, United States Air Force Frequency selective surfaces (FSSs) have important military and civilian applications including antenna theory, satellite communications and stealth technology Author is an authory on the subject, having been instrumental in the development of stealth technology for the US Air Force Much of the material in this book was deemed classified due to its importance to defence

This book offers a clear and interdisciplinary introduction to the structural and scattering properties of complex photonic media, focusing on deterministic aperiodic structures and their conceptual roots in geometry and number theory. It integrates important results and recent developments into a coherent and physically consistent story, balanced between mathematical designs, scattering and optical theories, and engineering device applications. The book includes discussions of emerging device applications in metamaterials and nano-optics technology. Both academia and industry will find the book of interest as it develops the underlying physical and mathematical background in partnership with engineering applications, providing a perspective on both fundamental optical sciences and photonic device technology. Emphasizing the comprehension of physical concepts and their engineering implications over the more formal developments, this is an essential introduction to the stimulating and fast-growing field of aperiodic optics and complex photonics.