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Electronics Letters

Issue 15 • Date July 24 1969

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Displaying Results 1 - 18 of 18
  • Design basis and characteristics of a special frequency-voltage convertor circuit

    Publication Year: 1969 , Page(s): 327 - 328
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (235 KB)  

    The requirements and characteristics of a frequency-voltage converter are established, together with the effect of a separate input variable T. Using the developed expressions, a computer program has been constructed so that accurate output predictions are readily available. View full abstract»

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  • Synthesis using active constant-resistance 3-terminal networks

    Publication Year: 1969 , Page(s): 328 - 330
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (327 KB)  

    A method of independent control over the polynomial coefficients of a transfer function is described. It employs 3-terminal constant-resistance networks and a unity-gain voltage amplifier. The constant-resistance building blocks are realised using gyrators and n.i.c.s, in addition to resistors and capacitors. View full abstract»

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  • Means of reducing computing time in the fast-Fourier-transform method

    Publication Year: 1969 , Page(s): 330 - 331
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (232 KB)  

    A technique is described by which the computing time required for the fast-Fourier-transform algorithm can be reduced at the expense of frequency resolution, with no reduction in accuracy. View full abstract»

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  • Active RC bandpass and highpass network

    Publication Year: 1969 , Page(s): 331 - 332
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (238 KB)  

    An active RC circuit is described, which can be used as a second-order bandpass or highpass filter. Its sensitivity is independent of the Q factor and very low. View full abstract»

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  • Reflection and transmission at an abrupt change in cross-section of a rectangular waveguide in the E and H plane

    Publication Year: 1969 , Page(s): 332 - 333
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (260 KB)  

    For a symmetric cross-sectional enlargement of a rectangular waveguide, the reflection and transmission coefficients of the H10 mode are calculated. At low frequencies, they agree well with the values for the H11 mode at an axial-symmetric junction of two circular waveguides. An axial offset of the two rectangular waveguides has a small influence on these coefficients. View full abstract»

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  • Surface-wave matched delay lines for pulse compression

    Publication Year: 1969
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (170 KB)  

    A system using dispersive ultrasonic lines for radar signal generation and compression has been tested. Surface waves on quartz are employed. Dispersion does not result from propagation but from nonuniform spacing of taps. Some oscilloscope traces of the correlation output are shown for linear f.m. signals having a time-bandwidth product of 80. View full abstract»

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  • Real dominant zero of a Hurwitz polynomial

    Publication Year: 1969 , Page(s): 334 - 335
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (291 KB)  

    A method presenting a very close approximation to a real dominant zero of a Hurwitz polynomial is given. The procedure is based on the Ostrowski method for calculating the zero of smallest modulus of a polynomial. View full abstract»

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  • Algorithm for matching 1-dimensional patterns in multidimensional space, with application to automatic speech recognition

    Publication Year: 1969 , Page(s): 335 - 336
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (262 KB)  

    An algorithm is described which selects corresponding points on two curves in multidimensional space. This simplifies comparison of two curves which have been derived as functions of an independent parameter (usually time), where this parameter does not vary in the same way along each curve. The problem arises in matching utterances for the purpose of automatic speech recognition. View full abstract»

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  • Precise comparison of resistance and capacitance

    Publication Year: 1969 , Page(s): 336 - 338
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (394 KB)  

    It is shown that previous Wien-bridge methods for the comparison of resistance and capacitance may be improved on, in that the effect of certain parasitic impedances may be eliminated. View full abstract»

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  • Conversion of an arbitrary node into a source node in a flow graph

    Publication Year: 1969 , Page(s): 338 - 339
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (251 KB)  

    A simple procedure which converts an arbitrary node into a source node for both the Coates flow graph and Mason's signal-flow graph is presented. The technique is believed to be simpler than the well known path-inversion process. View full abstract»

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  • Design formulas for active RC filters using operational-amplifier biquad

    Publication Year: 1969 , Page(s): 339 - 341
    Cited by:  Papers (17)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (383 KB)  

    Complete design formulas for realising any biquadratic voltage transfer function are given. The configuration uses ten or fewer resistors, two capacitors and four single-ended operational amplifiers. The realisation achieves extremely low sensitivity and can readily be used in realising stable high Q factor active filters up to 100kHz. View full abstract»

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  • Electrostatic probe in a flowing continuum plasma

    Publication Year: 1969 , Page(s): 341 - 342
    Cited by:  Papers (3)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (300 KB)  

    The transient behaviour of the current to a cylindrical probe in a flowing seeded flame plasma, after a large negative voltage is switched on the probe, is measured experimentally. The steady-state current in the flowing system is calculated from the transient behaviour at short times. View full abstract»

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  • Über den Entwurf linearer zeitvariabler Systeme (Design of linear time-variable systems)

    Publication Year: 1969 , Page(s): 343 - 344
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (271 KB)  

    Die Beschreibung eines Elementes durch einen allgemeinen Übertragungsoperator in Verbindung mit den zugehórigen Rechenoperationen (wie Addition, Multiplikation und Inversion) kann als Grundlag fÿr den Entwurf linearer zeit-variabler Systeme dienen. In der vorliegenden Arbeit wird dieses Problem fÿr Systeme mit einem Eingang und einem Ausgang und fÿr MehrgröBensysteme mit der Darstellung im Zustandsraum behandelt. Das dargestellte Synthesever-fahren ist insbesondere durch geringen Rechenaufwand gekennzeichnet. The description of an element by a general transfer operator in connection with the corresponding elementary operations (like addition, multiplication and inversion) can be considered as the basis for the design of linear time-variable systems. In the letter, this problem is treated for the single-input/single-output and the multivariable cases using the state-space representation. The synthesis method presented here is especially characterised by the very simple calculations involved. View full abstract»

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  • Demodulation of Pal signals with two uncritical delay lines

    Publication Year: 1969 , Page(s): 344 - 345
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (303 KB)  

    A Pal demodulator circuit is described, in which two ultrasonic lines are used instead of one. The achieved profit is a much greater tolerable delay error. View full abstract»

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  • Modified circuit model for the step-recovery diode to include nonzero transition time

    Publication Year: 1969 , Page(s): 345 - 346
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (329 KB)  

    A diode model is proposed which enables the effect of the intrinsic transition time to be accounted for in any frequency-domain analysis. The validity of this model is established by mathematically analysing the model as used in a transition-time test set. Practical measurements show that the evaluated model is independent of the method of measurement. View full abstract»

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  • Evaluating the secondary ionisation coefficients in gases using concentric coaxial electrodes

    Publication Year: 1969 , Page(s): 346 - 347
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (312 KB)  

    In corona tubes, the first Townsend ionisation coefficient ¿ varies with electric field in a dependence law, which in most gases is not known analytically. The generalised secondary ionisation coefficient ¿ may be evaluated from measurements of the breakdown potential, gas pressure and using tabulated values of the primary ionisation coefficient. An expression containing an integrand, which cannot be described by analytical function, must be then solved to obtain ¿. In the letter, ¿ is evaluated using a digital computer. The computation has been carried out so far in the inert gases, mercury vapour and in an additional seven molecular and polyatomic gases. View full abstract»

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  • Ring-laser bias using reciprocal optical components

    Publication Year: 1969 , Page(s): 347 - 348
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (328 KB)  

    Ring-laser biasing, to reduce nonlinear rotation sensitivity, normally requires either nonreciprocal optical components or rotation of the whole laser. It is shown that biasing can be achieved by using the finite transit time of light propagation between two time-varying optical phase shifters. View full abstract»

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  • Frequency dependence and energy storage of a class of a.c. measuring instruments

    Publication Year: 1969 , Page(s): 349 - 350
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (282 KB)  

    The frequency dependence of the sensitivity of a class of a.c. measuring instruments employing average electric and magnetic stresses is discussed theoretically. General electromagnetic theorems are used to relate the frequency dependence to the variation of electric and magnetic energies. Conditions for frequency independence are obtained for ammeters, voltmeters and (microwave) power meters operating at arbitrary frequencies. View full abstract»

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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.

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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