By Topic

Electronics Letters

Issue 11 • Date May 29 1969

Filter Results

Displaying Results 1 - 23 of 23
  • Some aspects of Gunn oscillations in thin dielectric-loaded samples

    Publication Year: 1969, Page(s):227 - 228
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (236 KB)

    The presence of a dielectric (dielectric plus metal) on the surface of a thin GaAs layer not only influences the growth of a space-charge wave, but also, depending on the configuration used, can produce a strongly inhomogeneous d.c. field distribution along the sample, inhibiting the usual domain oscillation pattern. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Loop coupling to a periodic dipole array

    Publication Year: 1969, Page(s):228 - 229
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (230 KB)

    Conditions are found experimentally for optimising the coupling between a looped feeder (transposed transmission line) and a log-periodic array of radiating dipoles. Under optimum conditions, the coupling is sufficient to be useful in practical antennas. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • High-efficiency continuous oscillations in silicon IMPATT diodes below the transit-time frequency

    Publication Year: 1969, Page(s):229 - 230
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (253 KB)

    C.W. room-temperature operation of silicon IMPATT diodes at the first subharmonic of the transit-time frequency has been observed in a high-efficiency mode. Efficiencies as high as 8.8% at 5GHz with 1.2 Wc.w. have been achieved with current densities no more than 1480A/cm2. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Small-signal impedance of space-charge-limited semiconductor diodes

    Publication Year: 1969, Page(s):230 - 231
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (324 KB)

    A generalised expression for the small-signal impedance of semiconductor diodes with unipolar space-charge-limited (s.c.l.) current is presented. The field dependence of carrier mobility, as well as ionised impurities (or deep traps), is taken into account. As long as the diffusion current can be neglected, these results appear to cover almost all cases of practical interest for Si, Ge or GaAs s.c... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Self-pumped parametric amplification with GaAs transferred-electron devices

    Publication Year: 1969
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (126 KB)

    The letter reports experimental results obtained with a non-degenerate-type self-pumped parametric amplifier using GaAs transferred-electron devices. Gains of as much as 30dB, noise figures as low as 18dB, and instantaneous gain-bandwidth products of about 50MHz have been obtained at Xband signal frequencies with the amplifier using GaAs transferred-electron devices oscillating at Q band frequenci... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • C.W. anomalous-mode operation in silicon planar IMPATT diodes

    Publication Year: 1969, Page(s):232 - 233
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (281 KB)

    Silicon planar IMPATT diodes which operate in the Read mode in the frequency range 4.5¿11.5 GHz have been observed to produce c.w. oscillations in the frequency range 0.5¿2.0 GHz. These u.h.f. oscillations commence at a current density of 250 A/cm2 and are accompanied by a 15¿20% decrease in the diode direct voltage. The d.c./r.f. power-conversion efficiency in the anomalous mode is approximate... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Realisability of uniform aperture distributions

    Publication Year: 1969, Page(s):233 - 234
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (287 KB)

    Physical realisability of uniform aperture distributions in planar-aperture antennas has been discussed in the light of Rhodes' interpretation of the volume integrals in the complex Poynting theorem. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Considerations in the design of a model propagation path to study obstacle diffraction

    Publication Year: 1969, Page(s):234 - 235
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (245 KB)

    Theoretical studies of obstacle diffraction are simplified by assuming the transmitter to be isotropic. The letter treats knife-edge diffraction of a nonisotropic transmitter to find the conditions under which a practical model propagation path will yield results that differ by not more than a specified small factor from those predicted by assuming the source to be isotropic. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Absolute-stability test for discrete systems

    Publication Year: 1969
    Cited by:  Papers (4)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (120 KB)

    A numerical absolute-stability test for nonlinear discrete systems is proposed. The test is derived from the similar test for continuous systems given by ¿iljak by the use of the bilinear transformation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Numerical analysis of forward and reverse bias potential distribution in a 2-dimensional p-n junction with applications to capacitance calculations

    Publication Year: 1969, Page(s):236 - 238
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (326 KB)

    A method is described for the calculation of capacitance and potential distribution in a 2-dimensional p-n junction such as that at the edge of stripe transistors. The method uses a numerical solution of a modified 2-dimensional Shockley-Poisson equation on a nonuniform mesh. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • First-order nonlinear systems governed by generalised Riccati partial-differential equation

    Publication Year: 1969, Page(s):238 - 239
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (271 KB)

    The letter presents a method of converting a class of first-order nonlinear systems, represented by Riccati type of partial-differential equations, into equivalent linear second-order systems. The familiar Riccati equations and the linear equivalent second-order equation form a particular case of this study. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Impedance-measuring method

    Publication Year: 1969, Page(s):239 - 240
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (280 KB)

    The method described measures the magnitude of an unknown impedance by a single unambiguous adjustment. The circuit presented is similar to the Starr and Grÿtzmacher bridges, but does not require repeated adjustment. The phase of the impedance may be found if desired. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modification to the receive-path waveguide feeder of Goonhilly aerial

    Publication Year: 1969, Page(s):240 - 241
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (271 KB)

    A description is given of the new oversized waveguide feeder developed for the 26m satellite-communication aerial at Goonhilly Downs, Cornwall. The feeder loss has been reduced from its former value of 0.7dB, to 0.31dB, using this installation, with a view to enabling the station to work to a new low-elevation Intellsat III satellite. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Oscillating circuit using nonlinear inductance

    Publication Year: 1969, Page(s):241 - 243
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (310 KB)

    An oscillating circuit with nonlinear inductance is examined. A general characteristic of an inductance is used. Using the method of Samoilo, expressions for the oscillation frequency, the current harmonics, the characteristics of the forced oscillations and the characteristics of the parametric resonance are obtained, without limitations on the oscillation amplitude. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Calculation of the complex permittivity of lossy dielectric materials using the Roberts-von Hippel standing-wave method

    Publication Year: 1969, Page(s):243 - 244
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (278 KB)

    A program has been written for calculating the complex permittivity e1 ¿ je2 of lossy dielectric materials using the Roberts-von Hippel method View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Reduced-voltage operation of a surface-elastic-wave amplifier

    Publication Year: 1969, Page(s):244 - 246
    Cited by:  Papers (6)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (474 KB)

    Experimental results obtained from a surface-wave amplifier using a segmented-drift-field electrode structure are reported. It is shown that significant electronic gain can be obtained at a much lower voltage than that required for conventional surface-wave amplifiers. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Technique for measurement of HCN-laser linewidth

    Publication Year: 1969
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (154 KB)

    The spectrum of the 311 and 337 ¿m lines of an HCN laser is examined with a high-resolution spectrum analyser. Although the outputs have spectral widths of the order of 100kHz, the spectral width of the difference frequency is less than 5kHz. The observed spectra widths are caused by mechanical instability. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Bistable electrical-switching behaviour in glasses and other media

    Publication Year: 1969, Page(s):246 - 247
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (337 KB)

    Reversible bistable electrical switching in uncommon thin-film glasses has recently been reported. A brief study of the mechanisms involved has produced evidence of similar switching in other insulators and air gaps. The device appears to function by producing a metallic bridge between the electrodes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Transformerless r.p. immittance synthesis from real-part specification

    Publication Year: 1969, Page(s):247 - 248
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (311 KB)

    A method is proposed for synthetising transformerless r.p. immittance for the case in which only their real part on the imaginary axis is of interest. The method presents the advantage of requiring a very low number of components and very simple computations. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Space-charge wave instability in a semiconductor exhibiting field-dependent diffusion coefficient and saturated drift velocity

    Publication Year: 1969, Page(s):248 - 249
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (279 KB)

    It is shown that, in a semiconductor biased in the saturation region, the combination of a field-dependent diffusion coefficient with a gradient in the steady-state electric-field distribution may lead to space-charge wave amplification. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Correlation of slow rates of rise of current with times to pinch in transient mercury-vapour plasma

    Publication Year: 1969, Page(s):249 - 251
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (386 KB)

    Measurements of time of maximum pinch in a mercury-vapour-plasma discharge over a range of voltages up to 5kV are not, at first sight, in agreement with values calculated by using the Leontovich-Osovets theory, which has been shown to apply in similar experiments with noble gases. The influence of the external circuit involving the ignitron switch, measuring shunt and associated stripline connecti... View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • TE and TM modes in transmission lines with circular outer conductor and eccentric circular inner conductor

    Publication Year: 1969, Page(s):251 - 252
    Cited by:  Papers (6)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (240 KB)

    TE and TM modes in transmission lines with circular outer conductor and eccentric circular inner conductor are calculated by the help of the method of conformal transformation. Some results are presented. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Comment: Leaky waves on a dielectric rod

    Publication Year: 1969, Page(s):252 - 254
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (472 KB)

    An approximate analysis by Arnbak has shown that solutions (near cutoff) to the cylindrical dielectric-rod transcendental equation (for n=0) possess the same symmetry in their complex top-sheet domain as that commonly found in planar interface structures. The letter shows that, for all solutions (n=0, 1, 2, ¿) on a lossless cylindrical dielectric rod, symmetry can only hold in the upper (proper) ... View full abstract»

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

Aims & Scope

Electronics Letters is internationally renowned for its rapid communication of new developments and emerging topics across the broad and interdisciplinary field of modern electronics and electrical engineering.

Full Aims & Scope

Meet Our Editors

Editors-in-Chief

Professor Chris Toumazou
Director of the Biomedical Institute
Imperial College, London, UK

Professor Ian White
Head of Photonics Research
University of Cambridge, UK