Directivity And Beamwidth Approximations For Large Scanning Dolph Chebyshev Arrays

Directivity and Beamwidth Approximations for Large Scanning Dolph-Chebyshev Arrays

Directivity and beamwidth for radiation patterns corresponding to the optimum Dolph-Chebyshev design have heretofore been determined by means of formulas that, although exact, are intractable to computation and not particularly open to physical interpretation. Approximate but accurate formulas are presented here in closed form, for the purpose of easy examination and computation of directivity and beamwidth for large scannable Dolph-Chebyshev arrays. Array length, number of array elements, the spacing of these elements, and the sidelobe level desired are parameters in this study. The maximum achievable directivity for Chebyshev arrays is in principle limited, regardless of how large the array becomes. Data is given to establish the array length required to obtain a value of directivity at some prescribed level below the maximum value. Comparisons between exact and approximate theory are presented in graphical form in such a way as to illustrate the lower limits of array size for which the approximations are valid. Element spacings less than a half-wavelength are included in this study. (Author).

Scientific and Technical Aerospace Reports

Advanced Array Systems, Applications and RF Technologies

Advanced Array Systems, Applications and RF Technologies adopts a holistic view of arrays used in radar, electronic warfare, communications, remote sensing and radioastronomy. Radio frequency [RF] and intermediate frequency [IF] signal processing is assuming a fundamental importance, owing to its increasing ability to multiply a system's capabilities in a cost-effective manner. This book comprehensively covers the important front-end RF subsystems of active phased arrays, so offering array designers new and exciting opportunities in signal processing. This book: * provides an up to date record of existing systems from different applications * explores array systems under development * bridges the gap between textbook coverage of idealized phased arrays and practical knowledge of working phased arrays * recognises the significance of cost to the realization of phased arrays * discusses future advances in the field that promise to deliver even more affordable arrays ['intelligent' or self-focussing/-cohering arrays] Engineers and scientists in the radar and RF technology industry will welcome the detailed description of array elements, polarisers, T/R modules and beamformers in Advanced Array Systems, Applications and RF Technologies. This book is also appropriate for postgraduate and advanced undergraduate students in electronic engineering, and for technical managers, researchers and students in the fields of radioastronomy and remote sensing. This book is a volume in the Signal Processing and its Applications series, edited by Richard Green and Truong Nguyen.