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Radio and Electronic Engineer

Issue 5 • Date May 1966

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Displaying Results 1 - 8 of 8
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  • A transfluxor program store for an airborne digital computer

    Page(s): 270 - 276
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (919 KB)  

    Non-destructive read-out devices for digital computer storage can have two advantages over volatile storage. Program information may not be lost in the event of computer or power supply malfunction, and economy can often be achieved in drive circuitry and power consumption. The transfluxor can be used for a store which has both these advantages, and is, moreover, electrically alterable at microsecond speeds. This paper discusses the design of a 2048-word 20-bit word-organized store, with particular reference to the severe requirements of an airborne environment. The wiring pattern is examined and economies peculiar to this type of store are explained. Brief details are given of the read amplifier, in which a novel method of sense-line switching gives rise to further economies in circuitry. View full abstract»

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  • Evaluation of high quality varactor diodes

    Page(s): 277 - 285
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (958 KB)  

    Recent measurement procedures used between 1 Mc/s and 40 Gc/s in evaluating very high cut-off frequency varactor diodes are discussed. The types of measurement are: bridge measurements at low frequencies, microwave coaxial line measurements, a transmission method near the diode series-resonant frequency, and a transmission method at diode parallel resonance. Typical results from each type of measurement are given. The effect of bias on the parameters of the simple equivalent circuit is described. Correlation of data from the four types of measurement has shown that the simple equivalent circuit does not describe the diode completely. Modification is necessary to take into account the effect at the junction of stray capacitance. Some attempt is made to relate parametric amplifier performance to the results of diode measurements. View full abstract»

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  • Performance and Realization of Broad-band Semiconductor Diode Frequency Triplers

    Page(s): 286 - 292
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (915 KB)  

    The paper deals with the mechanism of frequency multiplication by means of charge-storage diodes, discusses the theory of the noise of such multipliers, and shows the technical realization of a broadband frequency tripler with lumped-element circuitry. View full abstract»

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  • A real time seismic array data analyser and its associated event selector

    Page(s): 293 - 308
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1982 KB)  

    A specialized data processing machine is being developed, which will be capable of using data from an array of seismometers to derive information on the direction of arrival, phase velocity and energy-time distribution of body waves from distant seismic events. The organization and method of operation of the machine are described and reasons for the choice of system are discussed. A simplified correlator which automatically selects events from the background noise has been in operation for some time. A description of this unit and some results obtained with it are presented. View full abstract»

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  • The application of microelectronics to naval equipment

    Page(s): 309 - 313
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1346 KB)  

    The paper first discusses the design criteria for Naval electronic equipment and how far they are satisfied by microelectronics. Equipments for which microelectronics is being considered or is in use are briefly described. Finally some comments are made on the choice of a particular microelectronic technique. View full abstract»

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  • The performance of practical constant-resistance modulators in relation to their use in f.d.m. systems

    Page(s): 314 - 318
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (603 KB)  

    Ideally modulators with a constant input resistance produce no frequencies across their input terminals other than those impressed by the signal source. They are thus potentially important in simplifying the requirements of filters in multi-channel f.d.m. communication systems, and in the case of double-sideband signals, in eliminating filters since then the modulators can be directly paralleled. This paper discusses experiments to see how far constant-resistance modulators may approach ideal performance in practice; the results are very encouraging. View full abstract»

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  • Analysis of a coupled waveguide circulator using non-reciprocal attenuation

    Page(s): 319 - 323
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (498 KB)  

    This paper describes a coupled waveguide circulator in which the secondary waveguide is loaded with distributed non-reciprocal attenuation along the coupling length. In the forward direction of transmission, the difference in the attenuation constants between the two coupled waveguides is large and transmission takes place between the primary waveguide ports. The peak and average power capability for this direction is essentially that of the empty waveguide. In the reverse direction, the difference in the attenuation constants is essentially zero and complete transfer of power takes place between the two waveguides. The insertion loss for this direction of propagation is limited by the back-to-front ratio of the non-reciprocal loss. View full abstract»

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