By Topic

Antennas and Propagation, IEEE Transactions on

Issue 5 • Date September 1977

Filter Results

Displaying Results 1 - 25 of 30
  • [Front cover and table of contents]

    Publication Year: 1977 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (171 KB)  
    Freely Available from IEEE
  • Comments on the surface wave guided along an infinite dielectric plane layer

    Publication Year: 1977 , Page(s): 722 - 724
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Equatorial scintillations: A review

    Publication Year: 1977 , Page(s): 729 - 736
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (864 KB)  

    With the advent of satellite communications systems at frequencies varying from \sim140 MHz 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 rangi... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Ionospheric and plasmaspheric effects in satellite navigation systems

    Publication Year: 1977 , Page(s): 705 - 708
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (432 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the role of the geometrical optics field in aperture diffraction

    Publication Year: 1977 , Page(s): 688 - 695
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A variational principle for scattering from rough surfaces

    Publication Year: 1977 , Page(s): 708 - 710
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (336 KB)  

    A variational principle is developed for scattering of waves by rough surfaces. It provides a prescription for improving the results of other methods and also provides a quantitative measure of their accuracy. This makes it possible not only to select the best available analytical treatment for any given application, but also to improve its accuracy. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A spectral domain interpretation of high frequency diffraction phenomena

    Publication Year: 1977 , Page(s): 676 - 687
    Cited by:  Papers (24)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (1048 KB)  

    A spectral domain interpretation of high frequency diffraction phenomena is discussed using the concept of a spectral diffraction coefficient, which resembles Keller's coefficients. The solution of the two-dimensional problems of diffraction of an arbitrary field (with no caustics) by a half-plane is investigated and results are given for any observation angle including, in particular, asymptotic ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • 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 (8)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Evaluation of integrals arising in the theory of laser beam propagation through the atmosphere

    Publication Year: 1977 , Page(s): 724 - 725
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (152 KB)  

    General analytical expressions are given for two types of definite integrals of Bessel functions arising in the theory of laser propagation through the atmosphere which have previously been evaluated numerically only over a limited range of parameters. The expressions are also generalized to include the analogous integrals with the Bessel functions being replaced by the spherical Bessel functions. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Forward scattering due to rain at 11 GHz

    Publication Year: 1977 , Page(s): 646 - 649
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Element pattern bounds in uniform phased arrays

    Publication Year: 1977 , Page(s): 597 - 604
    Cited by:  Papers (8)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (760 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 universal \cos \theta bound. When the array spacing admits grating lobes, it... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Circular aperture distribution functions

    Publication Year: 1977 , Page(s): 714 - 716
    Cited by:  Papers (4)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Creeping waves on a perfectly conducting cone

    Publication Year: 1977 , Page(s): 661 - 670
    Cited by:  Papers (6)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (696 KB)  

    The rigorously formulated scalar and vector Green's functions for a perfectly conducting semi-infinite cone are approximated asymptotically to furnish the high-frequency creeping wave contributions when the source and observation points are both located on the cone surface. The results are expressed in the ray-optical format of the geometrical theory of diffraction and thus provide another canonic... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An experimental study of the circuit properties of coupled insulated antennas

    Publication Year: 1977 , Page(s): 627 - 630
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Measured field patterns of bare and insulated linear antennas in a material medium

    Publication Year: 1977 , Page(s): 700 - 705
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Missile base mounted microstrip antennas

    Publication Year: 1977 , Page(s): 604 - 610
    Cited by:  Papers (13)  |  Patents (3)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Natural resonances via rational approximants

    Publication Year: 1977 , Page(s): 657 - 660
    Cited by:  Papers (10)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On-axis fields of symmetric receiving paraboloid for normally incident wave

    Publication Year: 1977 , Page(s): 716 - 718
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (232 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 the f/D ratio and the frequency. Maximum field occurs for an f/D of 0.25, and for this case the actual and geometric foci coincide. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Short-pulse characteristics of the conical spiral antenna

    Publication Year: 1977 , Page(s): 621 - 626
    Cited by:  Papers (12)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (488 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 high Q , low-frequency resonance and impedance loading of the antenna. Special attention is directed to... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effect of a lossy jacket on the external field of a coaxial cable with an interrupted shield

    Publication Year: 1977 , Page(s): 726
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design of a stripline log-periodic dipole antenna

    Publication Year: 1977 , Page(s): 718 - 721
    Cited by:  Papers (29)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Using continuous aperture illuminations discretely

    Publication Year: 1977 , Page(s): 695 - 700
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandAbstract | PDF file iconPDF (536 KB)  

    An iterative procedure is described for fitting a continuous aperture illumination function to a small discrete element array such that the far-field antenna pattern has prescribed sidelobe behavior. Control of successive sidelobe levels in the array factor pattern is used to minimize an error expression comprised of the sum of the squares of the differences between calculated and specified levels... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Tilting antennas to reduce line-of-sight microwave link fading

    Publication Year: 1977 , Page(s): 642 - 645
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On discretizing continuous aperture distributions

    Publication Year: 1977 , Page(s): 617 - 621
    Cited by:  Papers (18)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Theory for microwave thermal emission from a layer of cloud or rain

    Publication Year: 1977 , Page(s): 650 - 657
    Cited by:  Papers (7)
    Save to Project icon | Request Permissions | 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»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

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

Full Aims & Scope

Meet Our Editors

Editor-in-Chief                                                 Kwok W. Leung