By Topic

IEEE Transactions on Antennas and Propagation

Issue 6 • November 1968

Filter Results

Displaying Results 1 - 25 of 40
  • [Front cover and table of contents]

    Publication Year: 1968, Page(s): 0
    Request permission for commercial reuse | PDF file iconPDF (538 KB)
    Freely Available from IEEE
  • Phase stabilization of widely separated oscillators

    Publication Year: 1968, Page(s):683 - 688
    Cited by:  Papers (7)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (531 KB)

    Techniques for reducing propagation-induced phase fluctuations in frequency distribution systems are discussed and compared. Examples of both microwave and optical methods are presented. Stabilization to a few parts in10^{8}over a 15-km path seems to be feasible. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effective boundary conditions for reflection and transmission by an absorbing shell of arbitrary shape

    Publication Year: 1968, Page(s):706 - 712
    Cited by:  Papers (59)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (631 KB)

    The reflection and transmission properties of an absorbing shell of arbitrary shape can be described by two algebraic boundary conditions relating the four tangential fieldsE_{+}, H_{+}, E_{-}, H_{-}at corresponding points on the outer surfaceS_{+}and inner surfaceS_{-}, respectively. The boundary conditions contain first-order curvature correction terms, but it is... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Scattering of a beam wave by a spherical object

    Publication Year: 1968, Page(s):724 - 727
    Cited by:  Papers (38)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (334 KB)

    The theoretical analysis of the scattering of a beam wave by a small spherical object, which exists at the neighborhood of the beam waist on the propagation axis, is treated. In this analysis, the property of a spherical object is generalized so as to have anr-dependent dielectric constant. Through numerical calculations for the case of the conducting sphere, the difference between the ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Nonlinear interaction of electromagnetic waves in bounded plasmas

    Publication Year: 1968, Page(s):737 - 741
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (369 KB)

    A method is presented for the solution of second-order electromagnetic fields in a bounded plasma which is excited by two high-frequency electromagnetic waves. Due to nonlinearities inherent in any plasma, incoming waves are mixed, creating sum and difference frequencies. The signal from the difference frequencyomega_{1}-omega_{2}, whereomega_{1}andomega_{2}are sou... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A log-periodic cavity-backed slot array

    Publication Year: 1968, Page(s):756 - 758
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (290 KB)

    This communication describes the element investigation, design, and testing of a backfire log-periodic cavity-backed slot array operating from 2.8 to 5.9 GHz in a frequency-independent fashion. The gain of the antenna is approximately 10 dB, and the VSWR is below 2.5 to 1. TheH-plane power patterns are given with nearfield plots along file array. The advantages of the antenna are a simp... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A note on the radiation characteristics and forced surface wave phenomena in triangular-grid circular waveguide phased arrays

    Publication Year: 1968, Page(s):760 - 762
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (306 KB)

    Forced surface wave resonances are shown to occur in dielectric-free 45-degree triangular-grid circular waveguide phased arrays. Similar surface wave phenomena were observed in an identical grid array of rectangular waveguides in theH-plane of scan. In the circular waveguide array, however, the resonance is observed in theE-plane and is shown to be an isolated point. This iso... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Pressure-formed parabolic reflectors for millimeter wavelengths

    Publication Year: 1968, Page(s):762 - 764
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (300 KB)

    An empirical investigation of metallic diaphragms deformed by uniform normal pressure to produce accurate parabolic reflectors is discussed. 30-cm diameter (f/D =0.4) reflectors produced by this technique were measured mechanically and found to have maximum deviations of only 0.5 mm orlambda/20at 30 GHz from a true paraboloid within a circle of 14-cm radius. Electrical measur... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An experimental study of a monopole over a grounded hemisphere

    Publication Year: 1968, Page(s):764 - 766
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (262 KB)

    Very little quantitative information is available on the behavior of an antenna over a nonplanar surface. A monopole over a metal hemisphere on a ground plane is a simple configuration which has possible applications to spacecraft antennas [1] and to broadcasting antennas erected on a hill. Measurements have been made of the driving-point admittance of a monopole with electrical lengthsbetah ... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A Poynting vector approach to creeping-wave analysis of the sphere

    Publication Year: 1968, Page(s):774 - 776
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (350 KB)

    A ray path geometry is derived using the Poynting vector to calculate the surface fields due to creeping waves in both theE- andH-planes of the sphere. The geodesics (great circles) are determined by assuming that at each point on the shadow boundary the initial direction of the ray is specified by the direction of real power flow calculated from the exact Poynting vector. Th... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contributors and back cover

    Publication Year: 1968, Page(s): c4
    Request permission for commercial reuse | PDF file iconPDF (2320 KB)
    Freely Available from IEEE
  • Theoretical and experimental studies on the long dipole antenna

    Publication Year: 1968, Page(s):664 - 673
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (832 KB)

    The long transmitting dipole antenna is studied theoretically and experimentally. The Wiener-Hopf technique is used to obtain explicit expressions for the current and charge distributions along the antenna. These quantities are also measured. The theoretical and experimental results are in good agreement. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Spectral resolution and solution of field problems in an anisotropic and compressible medium

    Publication Year: 1968, Page(s):741 - 745
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (360 KB)

    It is shown that when source currents are present in a compressible and anisotropic plasma, the longitudinal components of the electric and magnetic fields and the pressure variation satisfy a coupled inhomogeneous equation. Based on the spectral resolution of a square matrix, a general method for the solution of such an equation is presented. The solution of the coupled-wave equation is thus redu... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Radio propagation over a cylindrical hill including the effect of a surmounted obstacle

    Publication Year: 1968, Page(s):700 - 705
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (464 KB)

    An analysis is presented for wave propagation over a smooth cylindrical surface of constant curvature when the boundary impedance is specified. High-frequency approximations are introduced which permit a universal plot of the diffraction loss as a function of a hill-height parameter. The results are extended to allow for the presence of a knife-edge obstacle located on the crest of the rounded hil... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • ELF and VLF fields of a horizontal electric dipole

    Publication Year: 1968, Page(s):689 - 700
    Cited by:  Papers (20)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (952 KB)

    The waves in the spherical guide between the earth and ionosphere are excited by a horizontal electric dipole. The guide boundaries are characterized by surface impedances and the resulting waves are expressed as a superposition of TM and TE modes. The wavenumbers, excitation factors, height-gain functions, and height-dependent impedances are examined for both types of modes. A thin-shell approxim... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Conjugate echoes in Alouette-2 topside-sounder data

    Publication Year: 1968, Page(s):771 - 774
    Cited by:  Papers (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (504 KB)

    Three types of ionograms containing symmetric conjugate echo traces which appear frequently in the Alouette-2 satellite topside-sounder data are presented and explained in terms of multiple reflections between conjugate points of the field line passing through the satellite. Such symmetric traces have not been previously reported in the literature. The high intensity of these traces gives credence... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Log-periodic antennas with modulated impedance feeders

    Publication Year: 1968, Page(s):633 - 642
    Cited by:  Papers (15)  |  Patents (2)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (744 KB)

    The proper phasing of the active region of a log-periodic array can be obtained by means of a feeder without the conventional transposition of the wires. This is of practical importance for arrays of monopoles and slots where the transposition is not possible. However, the input impedance of such structures, when fed from a line with constant impedance, varies greatly with frequency. The impedance... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Studies of the focal region of a spherical reflector: Stationary phase evaluation

    Publication Year: 1968, Page(s):646 - 656
    Cited by:  Papers (8)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (784 KB)

    The geometric optics and polarization properties of a spherical reflector are used to develop an integral representation of its focal region fields. These integrals are evaluated by the extended method of stationary phase for field points off the caustics, on the axial caustic, on the caustic surface, and at the paraxial focus. The contributions to the field at a field point are shown to arise res... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis of mode conversion in waveguide transition sections with surface impedance boundaries applied to VLF radio propagation

    Publication Year: 1968, Page(s):673 - 678
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (528 KB)

    First- and second-order correction terms are derived for the reflection and transmission scattering coefficients for a step-type transition between two uniform waveguides with surface impedance boundaries. This analysis yields rigorous expressions for the differential transmission and reflection coefficients defined for an infinitesimal step transition. These coefficients are essential in the deri... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The arbitrarily driven long cylindrical antenna

    Publication Year: 1968, Page(s):769 - 770
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (232 KB)

    An approximate solution is described for the current distribution on a long, thin cylindrical antenna driven at an arbitrary point along its length. This solution is reasonably accurate, and the form is simple enough to be useful in the analysis and synthesis of antennas with lumped active or passive elements located along their length. View full abstract»

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

    Publication Year: 1968, Page(s):759 - 760
    Cited by:  Papers (1)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (256 KB)

    In order to reduce the space occupied by a reflector array, it is desirable to arrange the array antennas as close to each other as possible; however, in this case coupling between the array antennas will reduce the reflecting properties of the reflector array. The purpose of the present communication is to demonstrate that this is true for a Van Atta reflector consisting of four half-wave dipoles... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The pointing calibration of the Haystack antenna

    Publication Year: 1968, Page(s):746 - 751
    Cited by:  Papers (13)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (648 KB)

    We have applied techniques of optical astronomy to calibrate the pointing of a high-resolution pencil-beam antenna by using radiometric measurements of cosmic radio sources. The Haystack antenna, a 120-ft paraboloidal reflector on an azimuth-elevation mount, was calibrated at a frequency of 15.25 GHz. The beamwidth at this frequency is 36 millidegrees; the rms residual pointing error after calibra... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On antenna impedances in a cold plasma with a perpendicular static magnetic field

    Publication Year: 1968, Page(s):728 - 736
    Cited by:  Papers (3)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (808 KB)

    A flat strip antenna is embedded in a magnetoionic medium with its longitudinal axis perpendicular to the static magnetic field. The antenna characteristics differ for antennas oriented with their surfaces parallel and perpendicular to the static magnetic field. In the former case there are no resistance peaks for frequencies near the plasma frequency and the reactance of a short antenna is capaci... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A multipole-field study for the multiarm log-spiral antennas

    Publication Year: 1968, Page(s):656 - 664
    Cited by:  Papers (4)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (696 KB)

    The electromagnetic field radiated by an arbitrary source is represented as the multipule expansion of the left-hand circularly polarized and of the right-hand circularly polarized modal fields. In particular, the multiarm log-spiral antennas have been investigated using such an approach. With approximated current distributions, the multipole coefficients and the circularly polarized field pattern... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Determination of resonance conditions in dielectric- sheathed or plug-loaded phase arrays

    Publication Year: 1968, Page(s):753 - 755
    Cited by:  Papers (5)
    Request permission for commercial reuse | Click to expandAbstract | PDF file iconPDF (312 KB)

    Formulas are derived for the conditions of resonance in phased arrays either covered by dielectric slabs or loaded with dielectric plugs. Numerical results are obtained to show the effects on these resonances due to the waveguide wall thickness, dielectric constant, and the thickness of the slab or plug. 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                                             Danilo Erricolo