An exact method, involving the line vector z, is developed for calculating the characteristic impedances of stepped impedance transformers having maximally-flat and Chebyshev characteristics. It is also shown that thi...
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An exact method, involving the line vector z, is developed for calculating the characteristic impedances of stepped impedance transformers having maximally-flat and Chebyshev characteristics. It is also shown that this leads to considerable economy of effort compared with earlier methods.
The purpose of the paper is to show that by the use of the rational fraction expansion of transcendental functions, the exponential transmission line can be represented at all frequencies by networks comprising lumped...
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The purpose of the paper is to show that by the use of the rational fraction expansion of transcendental functions, the exponential transmission line can be represented at all frequencies by networks comprising lumped elements. The open-circuited and the short-circuited exponential lines are first considered; it is shown that there are three forms to represent each of these. In the cases of the open-circuited divergent line and the short-circuited convergent line, all the three forms yield physically realisable elements. But, in the cases of the open-circuited convergent line and the short-circuited divergent line, two forms can be physically realised when the impedance transformation ratio lies below 7.389 and only one form is realisable when it exceeds 7.389. It is shown that the exponential transmission line can be synthesized either by the use of the open-circuit impedance functions or by the shortcircuit admittance functions, taking, in both cases, only the networks whose elements are physically realisable for any length of the line, thus constituting the two basic forms.
It is explained why two particular equations be used for a study of space-wave propagation over irregular terrain. It is believed that these two equations provide a method of separating the systematic from the random ...
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It is explained why two particular equations be used for a study of space-wave propagation over irregular terrain. It is believed that these two equations provide a method of separating the systematic from the random effects of terrain irregularities. Our development of a transmission loss formula is based upon the determination of a smooth curved surface (either concave or convex) which approximates that part of the actual terrain which is effective in the ground-reflection process and the subsequent use of well-known methods of attenuation calculation applicable to such smooth, curved surfaces.
An exponential transmission line is useful for impedance transformations over a wide band of radio frequencies. It is shown that a four-wire line of the "side-connected" type employing uniform conductors, an...
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An exponential transmission line is useful for impedance transformations over a wide band of radio frequencies. It is shown that a four-wire line of the "side-connected" type employing uniform conductors, and in which the rates of taper change only once along the line, may be designed to approximate closely to an exponential line. Design equations and charts are given which aid in determining the wire sizes, values of taper, and change in taper for building some of these transformers.
Methods for facilitating the design of phase-shift oscillators at extreme frequencies of a fraction of a cycle to a few megacycles are discussed. It is shown that, if the input impedance of each section of a lumped re...
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Methods for facilitating the design of phase-shift oscillators at extreme frequencies of a fraction of a cycle to a few megacycles are discussed. It is shown that, if the input impedance of each section of a lumped resistance-capacitance network is made K times that of the previous section, the gain required for oscillation can be reduced to a theoretical minimum of 8 for a three-section network with K high, as against 29 for a K of unity. A new circuit element called the "resistance-capacitance transmission line," consisting of a resistance covered by a well-insulated and grounded metal surface, is introduced and is analyzed as a phase-shifting network to give reliable operation in a phase-shift oscillator at frequencies up to a few megacycles. Curves are presented to facilitate the design of the latter type of oscillator. Various configurations of the resistance-capacitance transmission line are discussed and experimental results are presented.
It is shown that in a loosely coupled transmission line directional coupler, a continuously tapered coupling factor having a nonzero finite value everywhere along the longitudinal direction and having continuous deriv...
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A large number of transmission lines have been erected without adequate consideration having been given to the ability of the line to stay in circuit electrically during the occurrence of lightning or other disturbanc...
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