Download or read book Directivity and Beamwidth Approximations for Large Scanning Dolph Chebyshev Arrays written by Charles J. Drane (Jr.) and published by . This book was released on 1965 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).

Download or read book Directivity and Beamwidth Approximations for Large Scanning Dolph Chebyshev Arrays written by Charles J. Drane (Jr.) and published by . This book was released on 1965 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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)

Download or read book Advanced Array Systems Applications and RF Technologies written by Nicholas Fourikis and published by Academic Press. This book was released on 2000-05-31 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Antenna Handbook written by Y.T. Lo and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 2282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Techniques based on the method of modal expansions, the Rayleigh-Stevenson expansion in inverse powers of the wavelength, and also the method of moments solution of integral equations are essentially restricted to the analysis of electromagnetic radiating structures which are small in terms of the wavelength. It therefore becomes necessary to employ approximations based on "high-frequency techniques" for performing an efficient analysis of electromagnetic radiating systems that are large in terms of the wavelength. One of the most versatile and useful high-frequency techniques is the geometrical theory of diffraction (GTD), which was developed around 1951 by J. B. Keller [1,2,3]. A class of diffracted rays are introduced systematically in the GTD via a generalization of the concepts of classical geometrical optics (GO). According to the GTD these diffracted rays exist in addition to the usual incident, reflected, and transmitted rays of GO. The diffracted rays in the GTD originate from certain "localized" regions on the surface of a radiating structure, such as at discontinuities in the geometrical and electrical properties of a surface, and at points of grazing incidence on a smooth convex surface as illustrated in Fig. 1. In particular, the diffracted rays can enter into the GO shadow as well as the lit regions. Consequently, the diffracted rays entirely account for the fields in the shadow region where the GO rays cannot exist.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1965 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Technical Abstract Bulletin written by and published by . This book was released on with total page 780 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Nonlinear Interaction of a Radio frequency Wave with an Inhomogeneous Plasma Slab written by Robert J. Papa and published by . This book was released on 1965 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characteristic Wave Cataloguing for Ray Path Determination written by Yūji Inoue and published by . This book was released on 1965 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wave cataloguing suitable for ray tracing of a pulsed wave packet in a weakly-dissipative, horizontallystratified magnetoionic medium is described, Particular attention is devoted to the cataloguing of the various characteristic waves so that the influence of the local ionization density and collision frequency can be understood. The procedure presented is applicable under general incident conditions and complex refractive index surfaces. The Booker quartic equation is used to derive the unambiguous wave normals and wave identification is obtained from the dispersion equation. A modified CMA. diagram including collisions is illustrated. (Author).

Download or read book The Control of Electromagnetic Scattering by Impedance Loading written by J. K. Schindler and published by . This book was released on 1965 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Satellite Observations of Low energy Primary Cosmic Ray Nuclei of Charges Z greater Than Or Equal To 6 written by Y. K. Lim and published by . This book was released on 1965 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Microwave Measurements of Partially Coherent Fields written by J. L. Poirier and published by . This book was released on 1965 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Application of a System of Fixed rotating Vectors to Circuit Analysis and Synthesis written by Carl T. Case and published by . This book was released on 1965 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: A system of fixed-rotating vectors can be used to study the impedance loci of functions of the first Foster form and of systems including negative impedance converters. Of particular interest in the field of dielectrics and biological membrane studies is a parallel RC network, where the dielectric of the capacitor is given by the Debye dispersion relations. Such a network also falls into the category of the first Foster form.

Download or read book A Method for Estimating Atmospheric Noise Amplitudes and Phase Errors in Quenched High Q Receiving Circuits written by E. A. Lewis and published by . This book was released on 1965 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: Very narrow-band quenched filters used for studying VLF radio signals differ from conventional narrow-band circuits in that both signal and atmospheric noise impulses cause only brief quasi-sinusoidal outputs instead of a prolonged ringing. The random overlapping of these short noise and signal bursts can cause errors in phase measurements. It is shown that the distribution of phase errors can be calculated from the amplitude distribution of the output noise envelope. The properties of the phase distribution are discussed in detail, the computation required in the general case is illustrated by means of a numerical example. A simple 'time-sequential' method for experimentally obtaining typical amplitude distributions is suggested. (Author).

Download or read book Substituted Perinaphthenyl Anion Radicals written by Tapan K. Mukherjee and published by . This book was released on 1965 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Plurality count Diversity Combining for Fading M ary Transmissions written by John N. Pierce and published by . This book was released on 1965 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The performance of a plurality-count diversity combiner for fading M-ary transmissions is analyzed, and calculated error probabilities are presented graphically for alphabet sizes of 2, 8, and 32. The performance is shown to be within 3 dB of that of an optimum square-law combiner for moderate alphabet sizes when there is no restriction on the allowable number of diversity branches. It is shown that a worthwhile saving in transmitted power can be effected by using nonbinary alphabets with plurality-count combining for the transmission of binary data. The availability of extra information from the combiner for use with error-correction is discussed.

Download or read book On Measuring the Radar Cross Sections of Ducks and Chickens written by P. Blacksmith (Jr.) and published by . This book was released on 1965 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Electron Capture from Atomic Nitrogen and Oxygen by Protons written by R. A. Mapleton and published by . This book was released on 1965 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: