Download or read book Investigation of Backfire Antenna written by Ngo The Hoanh and published by . This book was released on 1968 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Backfire Antennas and Impedance Loaded Slot and Wire Antennas written by Kun-Mu Chen and published by . This book was released on 1971 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is the final report under contract F19628-70-C-0072 and summarizes the research performed in the Department of Electrical Engineering and Systems Science, Michigan State University. Topics investigated were (1) the radiation and circuit properties of backfire antennas and open-cavity radiators, (2) the characteristics of impedance loaded slot antennas, (3) the properties of a multi-loaded cylindrical antenna, and (4) the modification of scattering by a multi-loaded slotted cylinder. (Author).
Download or read book A Dielectric rod Backfire Antenna written by J. A. Strom and published by . This book was released on 1969 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A backfire antenna is described which incorporates a dielectric slow-wave structure in place of the parasitic directors of earlier models. Using previously investigated optimum dimensions, this antenna uses new techniques of energizing in a cross polarized sense. Measurements of far-field patterns, directivity, and isolation between primary planes are given. (Author).
Download or read book Investigation of Impedance Loaded Slot Antennas and a Short backfire Antenna written by Tsing-zone Hsieh and published by . This book was released on 1971 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 The Short backfire Antenna written by Hermann W. Ehrenspeck and published by . This book was released on 1965 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Open cavity Radiators and Backfire Antennas Part I Open cavity Antennas written by Ming H. Hong and published by . This book was released on 1970 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research investigates the radiation and circuit properties of an open-cavity radiator. This antenna consists of a simple, open-ended circular cavity with a primary radiator, placed at an appropriate location inside the cavity. If a reflecting disk is placed at the aperture of this radiator, it becomes a short 'backfire' antenna. The waveguide excitation theory is employed to find the field excited in the cavity. The aperture field is then determined by summing the propagating modes at the open end of the cavity, and the radiation field is calculated based on the aperture field. The input resistance of the radiator is obtained from the total radiated power carried by the propagating modes and the input current of the primary radiator. Various primary radiators such as a dipole, a dipole array, a transmission line, and a circular loop are considered. An experimental study has been conducted parallel with the theoretical analysis and a satisfactory agreement has been obtained between theory and experiment. (Author).
Download or read book The Backfire Antenna written by Hermann W. Ehrenspeck and published by . This book was released on 1965 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Backfire Antenna written by Francis J. Zucker and published by . This book was released on 1966 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High gain UHF Backfire Antenna for Communications Telemetry and Radio Astronomy written by Hermann W. Ehrenspeck and published by . This book was released on 1967 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: The backfire antenna described combines the structural advantages of a single endfire with the high gain of a reflector antenna. With its principal application in the gain range between 15 and 30 dB where ordinary endfire antennas become impractically long and paraboloidal antennas too expensive, it should prove to be especially advantageous for telemetry and radio astronomy applications in the 100- to 2000-MHz frequency range. The high gain of the backfire is based on the high-amplitude standing-wave field distribution formed between two planar reflectors. The space between the reflectors acts like an open resonating cavity that in basic configuration and function resembles a Fabrey-Perot laser cavity. An S-band model of a 4.0-wavelength backfire produces a gain of 23.5 dB at its optimum frequency, which corresponds to the gain of an equal-size paraboloidal antenna of 60% efficiency. Patterns show a very low side- and backlobe level over a frequency range of 1.25 to 1. Design information for these backfire antennas is given. Compared with an optimized equal-length Yagi, the backfire antenna produces an increase in gain of more than 8 dB. To achieve a gain of this magnitude with an ordinary array, one of two recently built antennas for satellite applications uses 16 Yagis, each 2.0 wavelength long, to produce a gain of 22.4 dB, and another uses 36 cavity-backed slots to produce 21.2 dB. These results emphasize the advantages of the single-element backfire antenna, whose 23.5 dB gain is achieved through a simple structural design that does not depend on the complicated feed systems that are necessary components in multielement arrays. (Author).
Download or read book The Research on Short Backfire Antenna written by C. L. Lin and published by . This book was released on 1983 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Backfire Antennas written by Erik Drago Nielsen and published by . This book was released on 1969 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: A method for a theoretical investigation of arbitrary backfire antennas based upon the Yagi antenna structure was set up. The mutual impedances between the dipole elements of the antenna has been taken into account, and the field radiated due to a surface wave reflector of finite extent has been calculated using the method of physical optics. Numerical results obtained for Yagi backfire antennas, short-backfire antennas, and Yagi antennas using this theory were compared with numerical and experimental results obtained by others and with experimental results obtained in the Radio Anechoic Chamber of the Technical University of Denmark. (Author).
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 Backfire Antenna a New Type of Directional Line Source written by Hermann W. Ehrenspeck and published by . This book was released on 1961 with total page 1 pages. Available in PDF, EPUB and Kindle. Book excerpt: A description is given of the backfire antenna, a new type surface-wave radiator which consists of an ordinary endfire structure (Yagi, dielectric rod, and so forth) terminated by a plane reflector. The surface wave launched at the feed travels along the endfire structure until it impinges on the reflector; it then travels back toward the feed and radiates into space in a direction opposite to that of normal endfire operation. The gain of the backfire antenna is between 4 and 6 db higher than that of an ordinary endfire antenna of the same length; conversely, to achieve the same gain, the backfire antenna needs to be only between 1/4 to 1/3 as long as the ordinary endfire antenna. The side and back lobes can be kept extremely low. The backfire antenna will have wide application in cases in which the transverse dimension of the reflector does not violate ringe low-silhou t requirem nt . (Author).
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 0 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 Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt:
