This paper describes a new class of electrically small antennas, of which the principal advantages are the resistive input impedance, the radiation resistance transformation which may be obtained within the structure,...
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This paper describes a new class of electrically small antennas, of which the principal advantages are the resistive input impedance, the radiation resistance transformation which may be obtained within the structure, and the variety of shapes which the antennas may take. The antennas incorporate resonant half-wave windings, and a simple transmission line theory is presented by which antenna efficiency and bandwidth may be calculated. Experimental methods and results are described for antennas in the order of 0.01 wavelength in height and 0.05 wavelength in diameter.
In this paper are discussed some of the problems of the transformer design engineer in regard to the effect of different winding arrangements, and some of the means employed to predetermine transformer reactance and t...
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In this paper are discussed some of the problems of the transformer design engineer in regard to the effect of different winding arrangements, and some of the means employed to predetermine transformer reactance and to keep stray losses at a minimum. A reactance model has been developed to assist the transformer design engineer in checking reactance and stray loss calculations. COPYRIGHT 1934 by the American Institute of Electrical Engineers.
A theory of shot noise in junction diodes and transistors is presented, based upon a transmission line analogy. The noise is caused by the randomness in the diffusion of the minority carriers and the randomness in the...
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A theory of shot noise in junction diodes and transistors is presented, based upon a transmission line analogy. The noise is caused by the randomness in the diffusion of the minority carriers and the randomness in the recombination of minority and majority carriers. In transmission line analogy, first process corresponds to distributed noise emf's in series with transmission line, and second process corresponds to distributed noise current generators in parallel to transmission line. After magnitude of these equivalent distributed noise sources has been determined, noise problem is solved by standard methods. It is found that theoretical results for a junction diode agree with experimental work published earlier. An equivalent circuit describing the noise in transistors is presented. It contains two partially correlated noise current generators ip1and ip2, ip1,connected across the emitter junction and ip2 connected across the collector junction. ãip12‰av, ãip22‰av and ã*ip2‰Av are calculated. At low frequencies emitter and collector current show full shot effect and ip1, and ip2 are almost completely correlated;at higher frequencies the correlation becomes less complete. The noise can also be described by an emf es in series with the emitter and a current generator ip in parallel to the collector junction. Av are calculated. At low frequencies es and ip are uncorrelated, but some correlation is expected at higher frequencies. Low-frequency results resemble earlier equivalent circuits of Montgomery, Clark, and van der Ziel, and of Giacoletto. Copyright, 1955, by the Institute of Radio Engineers, Inc.
It is shown that the chain matrix parmeters of a nonuniform transmission line are interrelated and that, knowing any one of them, the other three may be determined. It is also shown that the parameters obey differenti...
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It is shown that the chain matrix parmeters of a nonuniform transmission line are interrelated and that, knowing any one of them, the other three may be determined. It is also shown that the parameters obey differential equations corresponding to those of either the voltage or current of the line.
X/sub L/-band waveguide switches, using PIN diodes for the switching elements, were developed in the SPST, SP2T, SP4T, and SP8T configurations. At the frequency of 7.75 GHz, for which they were tuned, they exhibited i...
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X/sub L/-band waveguide switches, using PIN diodes for the switching elements, were developed in the SPST, SP2T, SP4T, and SP8T configurations. At the frequency of 7.75 GHz, for which they were tuned, they exhibited insertion losses on the average of 0.1, 0.4, 0.6, and 1.1 dB, respectively. In all cases, the signal going out of each switch port when turned OFF decreased in excess of 29 dB. The bandwidth of each switch, whose values are indicated, is narrower for the switch which has the larger number of ports or which contains diodes of lower capacitance. Semiempirical formulas are developed which predict performance characteristics of the SPST switch in particular.
Curves are given here showing the equivalent shunt capacitance for step-type discontinuities in radial transmission lines for cases with the larger spacing outside, the larger spacing inside, and the re-entrant or sep...
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Curves are given here showing the equivalent shunt capacitance for step-type discontinuities in radial transmission lines for cases with the larger spacing outside, the larger spacing inside, and the re-entrant or septum type discontinuities. Corrections for dimensions comparable with wavelength and the proximity of a short circuit termination are discussed in addition to application of the results to cases with thin diaphragm or with changes of dielectric at the radius of the discontinuity. The basis for the analysis of the curves also is discussed briefly.
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