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IEEE Transactions on Antennas and Propagation

Issue 5 • September 1977

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  • [Front cover and table of contents]

    Publication Year: 1977, Page(s): 0
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    Freely Available from IEEE
  • Element pattern bounds in uniform phased arrays

    Publication Year: 1977, Page(s):597 - 604
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (746 KB)

    Limits are delineated within which the radiation pattern of a single excited element in an infinite regular array of terminated elements may be modified through a uniform feed or matching network. In the absence of grating lobes the element pattern of a planar array is limited by the universalcos thetabound. When the array spacing admits grating lobes, it will be shown that the bound is... View full abstract»

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  • Analysis of circular waveguide arrays on cylinders

    Publication Year: 1977, Page(s):610 - 616
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (558 KB)

    An analysis is given of the mutual coupling effects in a finite array antenna of circular waveguide elements on a conducting cylinder. The array is described in terms of a scattering matrix and the multimode aperture fields of the elements are solved for by moment methods. Mutual coupling through wave propagation along the surface is treated according to GTD, since for most cases of interest the s... View full abstract»

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  • Short-pulse characteristics of the conical spiral antenna

    Publication Year: 1977, Page(s):621 - 626
    Cited by:  Papers (18)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (475 KB)

    The short-pulse charactersitics of the conical spiral antenna are examined in detail. The antenna is anlyzed using a time-domain integral equation. Various peculiarities associated with the numerical solution procedure are discussed, including the effects of a highQ, low-frequency resonance and impedance loading of the antenna. Special attention is directed to the radiated-pulse propert... View full abstract»

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  • A new series representation for the radiation integral with application to reflector antennas

    Publication Year: 1977, Page(s):631 - 641
    Cited by:  Papers (70)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (880 KB)

    Given the true or any approximate current on a reflector, the radiated far-field is determined from a rapidly convergent series representation of the radiation integral. The leading term is a well-shapedJ_{1}(x)/xbeam pointing in a desired direction. Higher order terms provide perturbations to the leading term. The coefficients of the series are independent of the observation angles. He... View full abstract»

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  • Ionospheric and plasmaspheric effects in satellite navigation systems

    Publication Year: 1977, Page(s):705 - 708
    Cited by:  Papers (15)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (421 KB)

    A satellite navigation concept requires determination of time (or phase) delays that satellite-emitted signals experience when traversing the distance between satellite and observer. A pulse propagating this distance is slowed down somewhat from its free space velocity-by an amount directly proportional to the total number of free electrons (TEC) along its path. Ranging accuracy requirements manda... View full abstract»

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  • On-axis fields of symmetric receiving paraboloid for normally incident wave

    Publication Year: 1977, Page(s):716 - 718
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (223 KB)

    From a knowledge of the surface currents induced on a paraboloid reflector it is shown how the position of the peak scattered field on axis depends on both thef/Dratio and the frequency. Maximum field occurs for anf/Dof 0.25, and for this case the actual and geometric foci coincide. View full abstract»

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  • Comments on the surface wave guided along an infinite dielectric plane layer

    Publication Year: 1977, Page(s):722 - 724
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    It is emphasized that the surface wave generated by a dipole or line source along an infinite dielectric plane layer is represented definitely as Norton's surface wave type. Pertaining to this fact, is is stressed that the adoption of the residue term alone is insufficient in many cases especially when the case for a thin film is treated. View full abstract»

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  • Equatorial scintillations: A review

    Publication Year: 1977, Page(s):729 - 736
    Cited by:  Papers (51)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (851 KB)

    With the advent of satellite communications systems at frequencies varying fromsim140MHz to 1600 MHz as well as navigation and ranging systems in the 1200-1600 MHz portions of the spectrum, the effect of equatorial irregularities on fading signals has become of importance. Recent observations of the signal statistics of scintillations at frequencies ranging from 136 MHz to 6 GHz reveals... View full abstract»

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  • Approximate analysis of electromagnetic scattering from corrugated conducting surfaces by surface impedance modeling

    Publication Year: 1977, Page(s):721 - 722
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (208 KB)

    Scattering from a corrugated conducting surface is analyzed by an approximate method based on Leontovich boundary condition. Comparison of results with those based on a rigorous technique justifies the use of such approximate methods for shallow gratings. View full abstract»

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  • On the role of the geometrical optics field in aperture diffraction

    Publication Year: 1977, Page(s):688 - 695
    Cited by:  Papers (17)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (800 KB)

    The asymptotic solution of a high-frequency electromagnetic field transmitted through a finite aperture is studied. In applying Keller's geometrical theory of diffraction (GTD), a basic yet unanswered question for an observation point in the lit region is: "Should the geometrical optics field on a direct incident ray be included in the total field solution?" By studying a test problem and utilizin... View full abstract»

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  • Circular aperture distribution functions

    Publication Year: 1977, Page(s):714 - 716
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (272 KB)

    Hansen's recently described one-parameter distribution for the circular aperture and Taylor's earlier one-parameter line source distribution produce radiation patterns that are members of a broader two-parameter family originally described by Bickmore and Spellmire. As Hansan points out, his distribution is a compromise between various conflicting desirable characteristics. Among other things, det... View full abstract»

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  • Tilting antennas to reduce line-of-sight microwave link fading

    Publication Year: 1977, Page(s):642 - 645
    Cited by:  Papers (10)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (344 KB)

    Tilting the antennas up to obtain 2 dB loss (for each antenna) over maximum gain during steady signal conditions is shown to reduce fading over this particular path. The technique should also work on other paths where sufficient angular separation between the direct and reflected rays exists, and where antennas with sufficiently "sharp" main beams are used. View full abstract»

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  • Forward scattering due to rain at 11 GHz

    Publication Year: 1977, Page(s):646 - 649
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    Forward scattering from rain was measured at 11 GHz over a 9-km line-of-sight path. For rain rates of 100-150 mm/h, the scattered signal was observed to be about 40 dB below the direct signal. Good overall agreement was obtained between theory and experiment. View full abstract»

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  • Mean arrival time and mean pulsewidth of signals propagating through a dispersive and random medium

    Publication Year: 1977, Page(s):710 - 713
    Cited by:  Papers (16)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (392 KB)

    An electromagnetic pulse propagating through the ionosphere can be modified owing to dispersion as well as random scattering from electron density irregularities. As a result, the pulse arrival time and the pulsewidth are altered. In this paper we show how such quantities can be computed and related to the medium parameters. In this connection the two-frequency mutual intensity function enters in ... View full abstract»

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  • On discretizing continuous aperture distributions

    Publication Year: 1977, Page(s):617 - 621
    Cited by:  Papers (28)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (432 KB)

    A new method for applying continuous aperture design results to discrete antenna arrays is described. Instead of sampling the continuous aperture distribution, one requires that the pattern zeroes found in the continuous case also occur in the starting pattern for the discrete case. If the resulting pattern does not meet the design goal, a perturbation procedure is applied to the discrete distribu... View full abstract»

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  • Measured field patterns of bare and insulated linear antennas in a material medium

    Publication Year: 1977, Page(s):700 - 705
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    Apparatus designed to measure the electric field of bare and insulated linear antennas in fresh water is described. The transformation of the measured field to obtain far-zone patterns is discussed. Field patterns for bare antennas and for insulated antennas with concentric and eccentric insulation are compared, and the shaping of the pattern that can be obtained using the insulation is described.... View full abstract»

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  • An experimental study of the circuit properties of coupled insulated antennas

    Publication Year: 1977, Page(s):627 - 630
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    Measurements are reported of the admittances and distributions of current for two parallel insulated monopoles in lake water. Graphs of the admittance and impedance in the complex plane are displayed with the electrical distance between the elements as the parameter. These show significant coupling over electrically large separations. All data were obtained with the antennas driven both in phase a... View full abstract»

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  • Propagation of horizontally polarized waves through q2(x) profiles with simple zeros

    Publication Year: 1977, Page(s):727 - 728
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (216 KB)

    First Page of the Article
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  • Transient response of a thin wire to a moving charged particle

    Publication Year: 1977, Page(s):671 - 675
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (368 KB)

    The transient current on a thin wire induced by a charged particle moving parallel to the wire axis is studied. An explicit analytical solution for the induced current is obtained by utilizing the natural-mode method in conjunction with the method of asymptotic expansion. It is found that the solution can be split into two parts: one part consists of damped sinusoidal oscillations and the other ex... View full abstract»

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  • Natural resonances via rational approximants

    Publication Year: 1977, Page(s):657 - 660
    Cited by:  Papers (14)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    An approach for locating the dominant complex natural resonances (poles) of scatterers or radiators is described. Admittance values, calculated using Richmond's thin wire computer programs, at a regular grid of complex and real frequencies are fit by a rational function. Zeros of the resultant numerator and denominator polynomials then yield, respectively, the zeros and poles of the structure. The... View full abstract»

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  • Missile base mounted microstrip antennas

    Publication Year: 1977, Page(s):604 - 610
    Cited by:  Papers (18)  |  Patents (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (568 KB)

    Proof of the feasibility of aft mounting low-profile antennas on reentry vehicles is presented. This is an application of state of the art antenna hardware. Aft mounting presents the best reentry environment to antenna hardware, and its practicality has been demonstrated. Microstrip antenna principles can be used to produce very rugged antennas. Their low profile reduces many interface, mechanical... View full abstract»

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  • Effect of a lossy jacket on the external field of a coaxial cable with an interrupted shield

    Publication Year: 1977, Page(s): 726
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (128 KB)

    An earlier analysis is extended to allow for the influence of ohmic losses in the external dielectric jacket of a coaxial cable that has a circumferential slit in the outer metal shield. It is found that when the loss tangent is greater than zero, the radiation pattern is modified, particularly at angles near the axis of the cable. The external surface wave is then also attenuated. View full abstract»

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  • Design of a stripline log-periodic dipole antenna

    Publication Year: 1977, Page(s):718 - 721
    Cited by:  Papers (55)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (456 KB)

    A procedure is given for designing a two-layer stripline log-periodic dipole (LPD) antenna array. Measured input impedance and far-field characteristics are demonstrated for a 12-element array for 1-2 GHz operation that are in good agreement with design specifications. View full abstract»

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  • Theory for microwave thermal emission from a layer of cloud or rain

    Publication Year: 1977, Page(s):650 - 657
    Cited by:  Papers (27)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (608 KB)

    Microwave thermal emission from a layer of cloud or rain consisting of spherical particles has been investigated. Scattering effects are studied in great detail with both numerical and analytical approaches. In the absence of ground emission, it is found that scattering induces brightening for optically thin layers and vice versa for optically thick layers. As a function of observation angle brigh... View full abstract»

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IEEE Transactions on Antennas and Propagation includes theoretical and experimental advances in antennas.

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Editor-in-Chief                                             Danilo Erricolo