Showing papers on "Conformal antenna published in 1970"
TL;DR: A procedure is presented for predicting by computer the radiation pattern of an antenna in the presence of a radome, and good agreement between theory and experiment is noted.
Abstract: A procedure is presented for predicting by computer the radiation pattern of an antenna in the presence of a radome. The case of a horn antenna radiating through an actual aircraft radome is treated in detail, and a comparison is made between computed and measured antenna patterns. Good agreement between theory and experiment is noted.
84 citations
TL;DR: In this paper, a phased array antenna element which provides good circular polarization over a broad sector of coverage in an array environment has been designed and evaluated, where the concept is the superposition of complementary antennas, the dipole, and the slot, to achieve equal E - and H -plane patterns in the array environment.
Abstract: A phased array antenna element which provides good circular polarization over a broad sector of coverage in an array environment has been designed and evaluated. The concept is the superposition of complementary antennas, the dipole, and the slot, to achieve equal E - and H -plane patterns in the array environment. This element, when evaluated in a large test array, demonstrated an ellipticity of less than \pm2.0 dB over a coverage of \pm60 degrees. By proper control of the excitation of the two isolated antennas any desired polarization can be achieved.
35 citations
TL;DR: In this article, an array of infinitely long longitudinal slots equispaced on a conducting cylinder is analyzed in detail, and expressions for the eigenvalues of these matrices, and for the radiation patterns due to the array eigenexcitations, are found in the form of infinite series rapidly convergent (even for cylinders of large radius).
Abstract: The analysis of multiport antennas may be approached by resorting to the powerful concept of eigenexcitations of the structure. They may be defined as the eigenvectors of the admittance matrix, i.e., those sets of voltages and currents at the antenna terminals which are related simply by a proportionality factor (eigenvalue of the admittance matrix). Similarly, the eigenexcitations may be alternatively defined as the eigenvectors of the scattering matrix. The analysis for this special kind of excitation is sometimes relatively easy. The general case may then be treated by utilizing superposition principle. An array of infinitely long longitudinal slots equispaced on a conducting cylinder is analyzed in detail. The eigenvectors of the admittance and scattering matrices are easily found because of the symmetry of the structure. Expressions for the eigenvalues of these matrices, and for the radiation patterns due to the array eigenexcitations, are found in the form of infinite series rapidly convergent (even for cylinders of large radius). By using linearity an expression for the radiation pattern of the single excited element in the array environment (the main result of this paper) is then established. Expressions are also given for the coupling (or scattering) coefficients. A number of numerical examples with different cylinder radii are discussed in detail.
31 citations
TL;DR: In this article, a general numerical technique for analyzing monopole antennas protruding from a conducting sphere is suggested, and the results for special cases of antenna locations are compared to known and approximate solutions showing that the method is practical and accurate.
Abstract: A general numerical technique for analyzing monopole antennas protruding from a conducting sphere is suggested. Computed results for special cases of antenna locations are compared to known and approximate solutions showing that the method is practical and accurate.
28 citations
TL;DR: In this paper, the mutual impedance between the dipole elements of the antenna is taken into account, and the field radiated due to a surface wave reflector of finite extent is determined by calculating the surface current distribution on the reflector plate.
Abstract: A method is set up for a theoretical investigation of arbitrary backfire antennas based upon dipole structures. The mutual impedance between the dipole elements of the antenna is taken into account, and the field radiated due to a surface wave reflector of finite extent is determined by calculating the surface current distribution on the reflector plate. Numerical results obtained for Yagi backfire antennas and short-backfire antennas using this theory are compared with experimental results.
13 citations
TL;DR: A class of circuits is described that can be used with a phased-array antenna in order to allow a given array feed system to provide phase control for a phased array with many more elements.
Abstract: A class of circuits is described that can be used with a phased-array antenna in order to allow a given array feed system to provide phase control for a phased array with many more elements Alternatively, certain variations of these circuits can be used alone to provide phase control for small arrays while using only a single phase shifter for each direction of scan
7 citations
01 Jan 1970
4 citations
Patent•
14 Oct 1970
TL;DR: In this article, the phase-amplitude characteristics of the control signals are derived from a scaled array wherein individual elements are arranged in accordance with those of the operational conformal array.
Abstract: The radiation pattern of a conformal, quasi-uniform distribution of elements, each containing a radiating aperture, mixer and possible other active and passive components, is controlled by controlling the phase-amplitude characteristics of signals applied to the elemental mixers. The phase-amplitude characteristics of the control signals are derived from a scaled array wherein individual elements are arranged in accordance with those of the operational conformal array. The scaled system is illuminated by an electromagnetic or acoustic beam having the desired radiation pattern and the characteristics of the elemental signal within the elements of the scaled array control the radiation pattern of the conformal array in the desired manner.
3 citations
TL;DR: In this paper, the design and development of two types of stacked, vertically polarized, collinear arrays of three independently fed omnidirectional antennas operating at frequencies of 1550, 2702.5, and 4252.5 MHz are described.
Abstract: The design and development of two types of stacked, vertically polarized, collinear arrays of three independently fed omnidirectional antennas operating at frequencies of 1550, 2702.5, and 4252.5 MHz are described.
2 citations
01 Nov 1970
TL;DR: Unfurlable spacecraft antenna design and electrical characteristics, using Gregorian geometry with conical main and parabolic subreflector, were described in this paper, where the authors used the parabolic reflector as an antenna.
Abstract: Unfurlable spacecraft antenna design and electrical characteristics, using Gregorian geometry with conical main and parabolic subreflector
2 citations
TL;DR: 最近, とみに注目を集めているアンテナ, 最初概観的に解説した後, レーダー, 衛星通信, 電波天文用アANテナなどの応用について述べ,
Abstract: 最近, とみに注目を集めているアレイアンテナ, 特に電子走査のためのフェイズドアレイアンテナについて, 最初概観的に解説した後, レーダー, 衛星通信, 電波天文用アンテナなどの応用について述べ, 最後に, これらアレイアンテナに共通のアンテナ固有の諸問題について論じる.
02 Nov 1970
TL;DR: In this article, the authors describe one type of dual-frequency antenna that has been made operational in particular, this antenna is the MIT - Millstone Hill antenna, which has a dual-channel capability.
Abstract: : The need, in microwave tracking and radar systems for antennas with a dual-frequency capability, has necessitated the development of multi-frequency, multipurpose antennas It is the purpose of the report to describe one type of dual-frequency antenna that has been made operational In particular, this antenna is the MIT - Millstone Hill antenna
TL;DR: In this article, the satellite provides a uniform phase front and, for any appreciable elevation angle, meets the height requirement as a boresight source for large-aperture antennas.
Abstract: Theoretical and experimental results have shown that a satellite repeater can be used to measure accurately transmit and receive gains of ground-communications antennas. The satellite provides a uniform phase front and, for any appreciable elevation angle, meets the height requirement as a boresight source for large-aperture antennas.
01 Jan 1970
01 Jul 1970
TL;DR: In this paper, the basic techniques of beam formation, steering, and receive/transmit (transponder) functions of a phased array antenna system are reviewed for the first time.
Abstract: This is a survey paper wherein phased array antenna systems, now operating on spacecraft, are reviewed so as to reveal their basic techniques of beam formation, steering, and receive/transmit (transponder) functions. Laboratory developmental antennas, designed for ultimate spacecraft flight qualification, are assessed in terms of the needs of communications, earth resources instrumentation, and area surveillance.
01 Jan 1970
01 Jan 1970
12 Mar 1970
TL;DR: In this article, the initial results of a theoretical investigation of crossed-slot antenna elements arrayed on an aircraft to provide communications with satellites in the 225 to 400 MHz frequency range were presented.
Abstract: : Presented are the initial results of a theoretical investigation of crossed-slot antenna elements arrayed on an aircraft to provide communications with satellites in the 225 to 400 MHz frequency range. Calculations indicate that two four-element array antennas can approximate the desired performance of covering the hemisphere above the aircraft with more than 6 dB directive gain. Including the polarization loss between the elliptically polarized aircraft antenna and the circularly polarized satellite antenna, coverage is provided over about 90 percent of the desired area.