THIS PAPER will describe two variable-width fractional-nanosecond pulse generators utilizing tunnel diodes, back diodes, and snap-off diodes. These diodes have two impedance states whose magnitudes differ by approxima...
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THIS PAPER will describe two variable-width fractional-nanosecond pulse generators utilizing tunnel diodes, back diodes, and snap-off diodes. These diodes have two impedance states whose magnitudes differ by approximately two orders of magnitude. The diodes can be switched between the two impedance states during a fraction of a nanosecond in either direction. The pulse repetition frequency for the generators is in the 40 to 50 Mc range.
Sufficient conditions have been established under which a certain general type of circuit can be used to measure reflection coefficients. Several techniques are suggested for adjusting this type of reflection-coeffici...
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Sufficient conditions have been established under which a certain general type of circuit can be used to measure reflection coefficients. Several techniques are suggested for adjusting this type of reflection-coefficient meter.
Expressions are derived for the conductor loss in microstrip transmission lines. The formulas take into account the finite thickness of the strip conductor and apply to the mixed dielectric system. Good agreement with...
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Expressions are derived for the conductor loss in microstrip transmission lines. The formulas take into account the finite thickness of the strip conductor and apply to the mixed dielectric system. Good agreement with experimental data is obtained for rutile and alumina substrates.
The design and analysis of a 1-GHz limiter which uses voltage variation of the dielectric constant of a ferroelectric material to achieve limiting is described. An RF electric field derived from the input power is use...
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The design and analysis of a 1-GHz limiter which uses voltage variation of the dielectric constant of a ferroelectric material to achieve limiting is described. An RF electric field derived from the input power is used to change the relative dielectric constant /spl epsiv//sub r/ of the material; the resulting nonlinear change of capacitance of a small element of the material is used to change the condition of a tuned circuit. The tuned circuit terminates a quarter-wavelength stub which shunts the main transmission line, thereby providing a power-dependent mismatch at the junction of the two transmission lines. The degree of this mismatch is controlled by the condition of the tuned circuit and, therefore, the magnitude of the input power. Theoretical analysis and experimental results for small signal and large signal operation are presented. Limiter analysis is based on the measured change of ferroelectric (nonlinear) capacitance as a function of dc electric field. The ferroelectric element is 0.011 by 0.013 by 0.020 (inches) machined from polycrystalline (Pb/sub 0.315/-Sr/sub 0.685/) TiO/sub 3/ material.
The development of the 330-kv transmission system of the American Gas and Electric Company (AG&E) and of the Ohio Valley Electric Corporation (OVEC) involved the installation of a great number of circuit breakers....
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The development of the 330-kv transmission system of the American Gas and Electric Company (AG&E) and of the Ohio Valley Electric Corporation (OVEC) involved the installation of a great number of circuit breakers. The AG&E 330-kv system is superimposed on existing 138-kv transmission facilities. The OVEC 330-kv system was built to supply power from two new generating plants to the Atomic Energy Commission's diffusion plant at Ports-mouth, Ohio. The OVEC system is owned by 15 private utilities and is interconnected with the AG&E 330-kv system. Particularly in the case of OVEC, it is of the greatest importance to prevent, or limit in duration, unscheduled interruptions which could result in costly damage at the processing plant. To attain and maintain this high degree of service reliability, AG&E has made it a standard practice to field test new equipment whenever possible and, if required to apply the results to the betterment of the equipment and the service. The line-dropping investigation described in this paper is one of several carried out or planned in pursuance of these objectives. The particular circuit breaker described herein was completely restrikefree in its performance. Copyright 1957 by the American Institute of Electrical Engineers
In the preceding investigation the quantities upon which distance relays must depend for their operation have been determined for all possible types of faults occurring at a single location. It has been shown that the...
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In the preceding investigation the quantities upon which distance relays must depend for their operation have been determined for all possible types of faults occurring at a single location. It has been shown that the quantities obtained by the use of earlier distance relay connections for both line and ground faults do not give the closest approach to the desired result, a constant indication for all types of faults at a given location. It has been shown further that, by the use of different connections and certain auxiliary apparatus, a constant relaying indication may be obtained by the line relays for all types of line faults and by the ground relays for all types of faults involving ground, if the fault resistance is zero, and, if the fault resistance is not zero, that smaller deviations from the normal value will be obtained for a given fault resistance. The analysis has been based upon the assumptions of sine wave currents and voltages, constant circuit impedances, and negligible distributed capacitance in the faulted sections of line. It has been assumed further that the fault impedance is resistance only and that it is effectively constant throughout each cycle. All of these assumptions, except perhaps the latter, are reasonably valid as far as relaying is concerned, although some consideration must be given to the d-c component of the short-circuit currents with very high-speed relays.
The use of short-circuited transmission-line sections as wide-range resonant circuits in the 50-to 500-mc region is attended with one or more of these disadvantages: restricted tuning range with ordinary variable capa...
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The use of short-circuited transmission-line sections as wide-range resonant circuits in the 50-to 500-mc region is attended with one or more of these disadvantages: restricted tuning range with ordinary variable capacitors, limited choice of susceptance variation, poor impedance matching, and mechanical complexity. An analysis of an alternate method, using short, fixed-length transmission lines with a capacitor at each end, which overcomes these disadvantages, is carried through in normalized form to permit rapid graphical design of the lines and capacitors. The analysis is extended to include interstage coupling circuits and output circuits with a fixed coupling point.
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