By Topic

Antennas and Propagation, IRE Transactions on

Issue 4 • Date October 1956

Filter Results

Displaying Results 1 - 17 of 17
  • [Front cover and table of contents]

    Publication Year: 1956 , Page(s): 0
    Save to Project icon | Request Permissions | PDF file iconPDF (117 KB)  
    Freely Available from IEEE
  • News and views

    Publication Year: 1956 , Page(s): 587 - 591
    Save to Project icon | Request Permissions | PDF file iconPDF (485 KB)  
    Freely Available from IEEE
  • Circularly-polarized biconical horns

    Publication Year: 1956 , Page(s): 592 - 596
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (512 KB)  

    A new technique is described for obtaining circular polarization from a biconical horn. This polarization is obtained through use of a spatial array of thin conducting elements between the cone faces; orientation of the elements varies with distance from the feed. The method has been used successfully at S band and X band. This technique was applied to horns which have maximum radiation intensity in the plane normal to the cone axes as well as to other horns with beams tilted out of this plane. The beam tilt was obtained by an appropriate choice of cone configurations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Phase centers of microwave antennas

    Publication Year: 1956 , Page(s): 597 - 600
    Cited by:  Papers (16)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (347 KB)  

    This paper is concerned with the location of the phase centers of microwave antennas. The inadequacy of conventional aperture theory for the accurate description of phase centers is discussed. Formulas are developed and, for numerical indications, calculations are made for paraboloidal reflectors of different f/D ratios and a class of primary patterns which provide an approximate representation of a great many common feeds. The results are presented in graphical form to provide useful design information and show the dependence of principal E- and H- plane phase center location on feed and dish parameters. Contrary to the prediction of aperture theory, it is shown that the phase centers of axially symmetric antennas are not in the aperture plane, but they are dispersed about it. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A new method for the measurement of the average dielectric constant of the underground medium on site

    Publication Year: 1956 , Page(s): 601 - 604
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (344 KB)  

    An electromagnetic interference pattern in the far-distance condition is utilized to determine the average dielectric constant of the underground propagational medium. The method depends upon the determination of the surface wave velocity by means of measuring the first self-resonance frequency of a dipole wire laid on the earth's surface. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The image method of beam shaping

    Publication Year: 1956 , Page(s): 604 - 609
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (469 KB)  

    The image scheme of beam shaping for use at microwave frequencies is described. Cosecant-squared radiation patterns are obtained with parabolic reflectors no larger than those required to give pencil beams of commensurate beam widths. Radiation patterns calculated using diffraction theory are compared with measured patterns of a paraboloidal dish fed by a horn feed and one image horn. Experimental patterns are included to show the effects of variation of all parameters. A qualitative analysis of a paraboloid fed by a horn and several images is shown to agree with measured results. View full abstract»

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

    Publication Year: 1956 , Page(s): 610 - 618
    Cited by:  Papers (11)  |  Patents (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (900 KB)  

    Experimental measurements on three loop antenna configurations are presented. The technique for obtaining impedance and current distributions using a single-wire transmission line over an image plane is described with particular attention given to the difficulties encountered. The results are reproduced in graphical form, and for loops where theoretical results are available, curves comparing theory and experiment are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Systematic errors caused by the scanning of antenna arrays: Phase shifters in the branch lines

    Publication Year: 1956 , Page(s): 619 - 627
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (726 KB)  

    By choosing a suitable equivalent circuit representation for an array-type scanning antenna with the phase shifters in its branch lines, a general expression is derived for the radiation pattern in terms of the active impedances of the radiating elements, the incremental phase shift between elements, and the desired aperture distribution. If the active impedances of the radiating elements vary with beam position as a result of mutual coupling, or if the active impedances are constant, but different from the characteristic impedances of the branch lines, then an infinite series is required to represent the radiation pattern. The first term of the series is the desired pattern and the remainder can be defined as the systematic error. Individual terms of the series represent beams with relative angular positions which correspond to multiples of the interelement phase shift and with relative magnitudes which are dependent upon the deviation from a match of the active impedance of the radiators. The systematic error, if uncontrolled, can prevent the achievement of low sidelobe level. Experimental evidence is presented in support of the analysis. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A high-performance conically-scanning X-band antenna of novel design

    Publication Year: 1956 , Page(s): 628 - 631
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (457 KB)  

    A conically-scanning antenna is described which consists of a scanner mechanism, rear feed, and 8-foot diameter parabololoid producing a pencil beam having equal E- and H -plane beamwidths. The polarization may be quickly changed from linear to circular to vertical polarization. The sense of the polarization is readily changed from left-hand to right-hand. The replacement of one section of transmission line by a half-wave plate changes the unit from a nutating polarization scanner to a twice-scan-speed rotating polarization scanner. The scanner incorporates some novel features such as a symmetrical rear feed having equal E- and H -plane patterns, high-power quarter-wave and haft-wave plates, and an orthogonal mode absorber. This paper describes the techniques which were employed to obtain the above mentioned performance. The problems encountered and their solutions are described. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Slot admittance data at Kaband

    Publication Year: 1956 , Page(s): 632 - 636
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (506 KB)  

    Admittance data on transverse edge slots in RG-96/U waveguide can be obtained by a technique called the moving lossy short technique. By this technique the radiation attenuation of a test section of identical slots can be determined. It is then possible to specify both the slot inclination angle and the slot depth of cut required to yield any conductance with in the range of measurements. These data were used to design an experimental 30-slot array with a 25-db Taylor aperture distribution. This array was successful, yielding sidelobes near -23 db. Subsequently, the same data were used in designing an 8-foot array with 432 edge slots having the same aperture distribution. This array had a half-power beamwidth of 14 minutes and sidelobes of the order of -24 db. These results compared favorably with design objectives. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Radiation by disks and conical structures

    Publication Year: 1956 , Page(s): 637 - 640
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (395 KB)  

    The Lebedev integral transform is applied to a class of boundary value problems in the theory of diffraction and antennas, including circular disks, apertures and hollow conical structures. It is found that the conventional Wiener-Hopf technique, together with this transform, does not explicitly solve these problems. Instead, one is led to an infinite system of linear equations for the representation of the unknown transform function. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Diffraction of microwaves by tandem slits

    Publication Year: 1956 , Page(s): 640 - 649
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1289 KB)  

    The diffraction of a plane electromagnetic wave by two identical slits in tandem is investigated for normal incidence with the polarization parallel to the edges of the slits. Theory shows that the scattering cross-section coefficient is proportional to the imaginary part of the far field forward scattering factor. The stationary form of the scattering cross section is developed in terms of the incident field and unknown currents on the edges of the conductors forming the slits. Calculations using the Kirchoff-type approximation in this stationary form for a tandem slit separation of 0.157\lambda are in good agreement with the experimental values for slit widths greater than 0.5\lambda . Similar calculations for zero tandem slit separation, corresponding to a single slit, and for slit widths greater than 0.3\lambda are in good agreement with those of the exact theory of Morse and Ruberstein, and as determined experimentally. The infinitely long slits are approximated experimentally by use of a parallel plate system described earlier by Row. The experimental results show an interesting resonance effect as the slit width changes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transmission characteristics of inclined wire gratings

    Publication Year: 1956 , Page(s): 650 - 654
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (508 KB)  

    Small diameter parallel wires were imbedded in thin plastic sheets and located closely before an antenna dish receiving plane wave X band energy. Polarization was parallel to the wires, and the grating interval was varied between a fifth-wavelength and a whole wavelength for different panels. Received intensity was measured for varied grating tilt angles about an axis lying parallel to the wires and near the center of each panel. Sharp and intense transmission dips were observed for tilt angles at which the parasitic reradiation maxima lay in or near the end-fire direction. The shapes and angular positions of the transmission vs tilt angle curves are approximated by a tentative theory which assumes that the input impedance of the grating is independent of tilt angle and that the apparently absorbed power is proportional to the areas under plots of antenna array patterns. A more precise theory which includes the effect of varying input impedance was required to predict approximate amplitudes as well as sharp transmission dips of smaller magnitude. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On resonance in infinite gratings of cylinders

    Publication Year: 1956 , Page(s): 654 - 661
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (815 KB)  

    The diffraction by a grating is examined (for spacing large compared to wavelength and dimension of grating element) for wavelengths in the neighborhood of the "Rayleigh" wavelengths. The shape of the elements, and their size in wavelengths is unrestricted. The results, including the effect of interaction, are expressed in terms of quantities relating to single scattering. Some properties of certain determinants formed from single scattered amplitudes are derived. The results are compared with those obtained by other authors, using various restrictions on the parameters. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Line-of-site wave propagation in a randomly inhomogeneous medium

    Publication Year: 1956 , Page(s): 661 - 665
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (460 KB)  

    Theoretical calculations have been made, using the single-scattering approximation, for propagation in a randomly inhomogeneous medium in which the deviations of refractive index from the mean are small. The statistical quantities considered were the variance, correlation function, and power spectrum for the phase and relative amplitude of the field at a point and their differences at two points. The emphasis in this paper is in indicating the transition from the ray treatment results to the scattering cross section results. The correlation function for the refractive index is taken to be time as well as space dependent so that the power spectrum can be computed from the original formulation. View full abstract»

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

    Publication Year: 1956 , Page(s): 666 - 671
    Cited by:  Papers (202)  |  Patents (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (619 KB)  

    Multiple reflections of electromagnetic waves between two planes are studied, and the increase in directivity that results by placing a partially reflecting sheet in front of an antenna with a reflecting screen is investigated at a wavelength of 3.2 cm. The construction and performance of various models of such arrays is discussed. Thus, for example, a "reflex-cavity antenna" with an outer diameter of 1.88 \lambda and an over-all length of only 0.65 \lambda is described which has half-power beamwidths of 34\deg and 41\deg in the E and H planes, respectively, and a gain of approximately 14 db. It is shown that larger systems produce considerably greater directivity but that their efficiency is poor. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • [Back cover]

    Publication Year: 1956 , Page(s): c4
    Save to Project icon | Request Permissions | PDF file iconPDF (1155 KB)  
    Freely Available from IEEE

Aims & Scope

The Transactions ceased publication in 1962. The current retitled publication is IEEE Transactions on Antennas and Propagation.

Full Aims & Scope