Download or read book Short Backfire Antenna Modeling With Dipole Or Waveguide Excitation written by G. P. Otto and published by . This book was released on 1992 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A three-dimensional short backfire antenna structure with circular symmetry is modeled using the mode matching method and the vector Hankel transform. The excitations considered are thin wire dipole antennas and flush waveguide feeds. The efficiency of computation can be increased by ignoring the higher order harmonics in the model. Then this model is used to design a structure with a larger directivity than previously reported. Theoretical predictions of the radiation pattern yield good agreement with measurements performed on a prototype. In addition, this model could be modified to approximate rectangular waveguide excitations or corrugated cavities.
Download or read book The Short backfire Antenna as an Element for High gain Arrays written by Hermann W. Ehrenspeck and published by . This book was released on 1971 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The short backfire (SBF) antenna consisting of a large reflector illuminated by a dipole feed and smaller disk reflector produces a gain of 15 dB above isotropic. As an array element it has been efficiently adapted for various configurations of high-gain antennas producing gains of up to 25 dB, with a single SBF element capable of replacing four to six elements of a conventional multidipole array. Farfield patterns and directivity measurements are presented for a single element and for a twin element mounted on a common reflector. Optimized dimensions for both cases are discussed for possible application to more complex types of antennas.
Download or read book Influence of Variation of Backfire Antenna Parameters II Short Backfire Antenna written by Erik Drago Nielsen and published by . This book was released on 1970 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large number of numerical and experimental results showing the influence of a variation of the antenna parameters on the radiation properties of a short-backfire antenna are presented. These results may be very useful for the design of such antennas. The numerical results were calculated on a digital computer using a previously published theory for backfire antennas with dipole elements. The experimental results were measured in a radio anechoic chamber. Other numerical results were obtained, which show that the radiation properties of the short-backfire antenna correspond to those of open resonators. Finally, a number of computations were carried out in order to investigate the possibility of applying the short-backfire antenna as the excitation system of a Yagi antenna. (Author).
Download or read book The Short Backfire Antenna A Numerical Physical Optics Study of Its Characteristics written by Tsing-Zone Hsieh and published by . This book was released on 1971 with total page 115 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical-physical optics method is applied to study the circuit (impedance) and radiation characteristics of the short-backfire antenna. This radiator, developed through extensive experimentation by AFCRL, consists of a dipole exciter located between a large rimmed reflector and a small secondary reflector. It has wide bandwidth and high directivity comparable to sophisticated reflector antennas. In the numerical-physical optics method, the following steps are followed: (1) a set of coupled integral equations for the currents excited in the dipole and on the surface of the secondary reflector are formulated and solved numerically, assuming for this step that the large reflector is infinite; (2) the surface currents of the large reflector are approximated by a truncated form of those calculated for the infinite conducting sheet; (3) the radiation field maintained by the currents of the steps (1) and (2) is calculated; and (4) a diffracted field correction is made to account for the finite dimensions of the large reflector and its rim. This method has the advantage, relative to earlier studies, that it can successfully predict the antenna's circuit characteristics. Excellent results are obtained for both square and circular geometries. Comparison is made with experimental measurements made by AFCRL. (Author).
Download or read book A Short Backfire Antenna Fitted with a Waveguide Feed written by John A. Strom and published by . This book was released on 1976 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: A short backfire antenna incorporating an open-ended waveguide as its feed mechanism has been measured experimentally in three different structural configurations. A complete set of curves describing the directivity, sidelobe levels, and half-power beamwidths as a function of frequency, as well as a few of the more important radiation patterns, are presented for each case. The effects obtained by varying parameters such as disk diameter and waveguide spacing are discussed, especially with regard to the directive gain and area illumination efficiency. Recommendations are made on techniques for fabrication, impedance-matching, and arraying antennas of this type for possible airframe applications. (Author).
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1987 with total page 1126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Advanced Antenna Technology written by P. J. B. Clarricoats and published by . This book was released on 1981 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Application of a Waveguide Feed to a Short Backfire Antenna written by A. C. Large and published by . This book was released on 1973 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Application of a waveguide feed to the short backfire type of antenna produces a simple, compact antenna design suitable for use with high microwave powers. The antenna can replace waveguide fed horns and polyrods that have similar radiation properties but have considerably greater physical length. Waveguide feeds with both rectangular and circular cross sections were tested on an experimental antenna. (Author).
Download or read book NASA Tech Briefs written by and published by . This book was released on 2008 with total page 1144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Summary of Engineering Research written by University of Illinois at Urbana-Champaign. Office of Engineering Publications and published by . This book was released on 1992 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modern Antenna Design written by Thomas A. Milligan and published by John Wiley & Sons. This book was released on 2005-07-11 with total page 646 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical book written for engineers who design and use antennas The author has many years of hands on experience designing antennas that were used in such applications as the Venus and Mars missions of NASA The book covers all important topics of modern antenna design for communications Numerical methods will be included but only as much as are needed for practical applications
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992 with total page 1494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microwave Cavity Antennas written by Akhileshwar Kumar and published by Artech House Antenna Library. This book was released on 1989 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1989 with total page 932 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Influence of Variation of Backfire Antenna Parameters 1 written by Erik Drago Nielsen and published by . This book was released on 1970 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A large number of numerical results for Yagi backfire antennas are presented, from which the influence of a variation of the antenna parameters may be deducted. The results were obtained by means of a previously described theory for backfire antennas with dipole elements, and the numerical computations were carried out on a digital computer. Samples of the numerical results were compared with experimental results obtained in a radio anechoic chamber. Finally, the influence of small changes in the general Yagi backfire antenna structure, such as changing the single dipole reflector elements into a half-transparent or solid conducting plate or changing the array of equally long dipole director elements into a tapered array, was investigated. (Author).
Download or read book Bibliography of Microwave Optical Technology written by A. F. Harvey and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt: Although microwaves and coherent optics, being two of the largest and most useful branches of electrical engineering to emerge technologically, are usually considered as distinct subjects, many of the underlying fundamental principles, scientific achievements, and practical applications have common features. Following the evolvment of the initial principles and techniques during the closing decade of the last century, microwave engineering has long matured to a stage of ready availability of components, automation and accuracy of measurement, economical manufacturing methods, and application of sophisticated systems. Further, this development of electromagnetic phenomena having spatial and temporal coherence has, based on several centuries of study and practice of noncoherent light, in the last two decades reached the optical region. Hence, it is now practicable to consider a comprehensive treatment of these two fields, division being made by subject matter rather than by the artificial distinctions of frequency and/or wavelength ranges. However, a full text on the combined subjects would be very large and unwieldy and, thus, this Bibliography is presented in the hope that it will prove useful as a compact reference source to a large body of workers and, by putting forward the latest scientific and technical advances, stimulate a multi-disciplinary approach. The material of the book commences with the fundamentals of radiation and matter, progressing through components and devices, amplification and generation, transmission, reception and processing of information, and methods of measurement to conclude with a wide range of applications.
Download or read book Japanese Science and Technology 1983 1984 written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Branch and published by . This book was released on 1985 with total page 1080 pages. Available in PDF, EPUB and Kindle. Book excerpt:
