A new wide-band strip-line balun that uses a pair of dual coupled-strip-line band-pass filters is described. It can operate over bandwidths up to about 8:1 in the frequency range of about 100 to 10,000 mc. Design data...
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作者：
Dellenbaugh, F.S.Secretary
Research Div. Electrical Eng. Dept. Mass. Inst. of Technology. United States
Review of the Subject.—Artificial transmission lines have been very valuable in developing the theory of transmission of power. This theory has been developed in great detail for steady state conditions, and it is no...
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Review of the Subject.—Artificial transmission lines have been very valuable in developing the theory of transmission of power. This theory has been developed in great detail for steady state conditions, and it is now important to extend it to cover transient conditions. This can best be done upon artificial transmission lines but the usual lumpy type of line introduces parasitic reflections caused by the discrete units of inductance, and therefore are of very limited use for this purpose. Attempts have been made from time to time to produce artificial lines with distributed constants, but the results were either unsatisfactory or expensive and bulky. A method, originally proposed by Pupin, has been developed by which small compact and cheap artificial transmission line coils can be designed and built to represent any desired configuration of circuit. These involve tinfoil wound in with the wire between the different layers, insulated from the winding by the usual form of condenser dielectric paper. One of the most difficult parts is to arrive at a coil with the proper constants. Formulas have been derived for doing this which will calculate the result given by the coil within the limits of manufacturing error, and which can be used in a straightforward manner similar to the design of other electrical apparatus. Either single or polyphase lines may be represented, and a single-phase line representing the average configuration of a 110,000-volt line approximately 1000 miles (1600 km.) long has been constructed and successfully used for test over a period of about one year. A three-phase line of similar characteristics, but 400 (640 km.) miles long, has also been constructed and is now being used in experimental investigations. The cost of such lines is low, being approximately 6 cents per mile per phase, excluding the cost of mounting. There are certain limitations of equivalence, but these are in secondary effects which do not cause serious error. One feature contri
This paper covers the development of LC equivalent circuits for the simulation of a lossless short circuited transmission line. A total of eight different equivalent circuits are obtained through the application of ci...
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This paper covers the development of LC equivalent circuits for the simulation of a lossless short circuited transmission line. A total of eight different equivalent circuits are obtained through the application of circuit theory and residue calculus. Each of the circuits has its advantages and disadvantages depending upon the desired application. In this paper, the equivalent circuits are rated by their ability to simulate a short circuited transmission line in the testing of circuit breakers.
The analysis of transmission-line directional couplers is formulated in terms of a pair of first-order matrix differential equations. It is shown that for every nonuniform directional coupler that is electrically symm...
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The analysis of transmission-line directional couplers is formulated in terms of a pair of first-order matrix differential equations. It is shown that for every nonuniform directional coupler that is electrically symmetric, there exists an equivalent pair of dual nonuniform transmission lines. It is also shown that a matched, transmission-line directional coupler having an absolutely continuous characteristic impedance matrix must be symmetric. Restrictions on the terminating impedances and the implications of these restrictions on the realizability of transmission-line couplers are investigated. Finally, the tapered-line magic T is treated as an example.
The maximum absolute impedance for a tuned circuit which consists of a low-loss radio-frequency transmission line, either short-circuited or open-circuited at its distant end, and shunted at its sending end by a capac...
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The maximum absolute impedance for a tuned circuit which consists of a low-loss radio-frequency transmission line, either short-circuited or open-circuited at its distant end, and shunted at its sending end by a capacitor of negligible resistance is shown theoretically to occur when the line length is practically an integral number of quarter wavelengths and the capacitance is zero. This conclusion disagrees with previous theoretical results, which indicated shorter optimum lengths. It is pointed out that the earlier results are incorrect because of the neglect of the quadrature component of the characteristic impedance. An experimental verification of the theoretical results is provided. Copyright, 1939, by The Institute of Radio Engineers, Inc.
This paper, Part II of a group on theory of primary electric power distribution networks, deals with short-circuit and relay problems. Data showing the distribution of fault currents for both 3-phase and ground Faults...
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This paper, Part II of a group on theory of primary electric power distribution networks, deals with short-circuit and relay problems. Data showing the distribution of fault currents for both 3-phase and ground Faults is presented, and a rational method of relaying based upon that data is discussed and analyzed. COPYRIGHT 1934 by the American Institute of Electrical Engineers.
A new analysis is given of direct-coupled-resonator filters that results in excellent response at much greater bandwidths than has previously been possible. The method relies on the fact that the coupling elements can...
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A new analysis is given of direct-coupled-resonator filters that results in excellent response at much greater bandwidths than has previously been possible. The method relies on the fact that the coupling elements can be made into perfect impedance inverters, or "quarter-wave" transformers, by the addition of negative elements in lumped-constant circuits, or of short negative lengths of line in waveguide and transmission-line circuits. Specific design formulas are given for filters constructed of lumped-constant elements, waveguide, and strip or other TEM transmission line, and for pass band response functions of the maximally flat and Tchebycheff types. The formulas include a simple frequency transformation that corrects for the frequency sensitivity of the coupling reactances, and thereby greatly improves the design accuracy for both lumpedconstant and microwave types when the bandwidth is more than a few per cent. Exact response curves computed from typical filter designs are compared to the prototype-function response curves, and it is shown that the design formulas give good results with bandwidths of at least 20 per cent in guide wavelength in the case of waveguide filters, or 20 per cent in frequency for TEM-mode transmission-line and lumped-constant filters.
The impedance of some broadcast antenna arrays varies so much over the transmitted band as to impair the performance of the radio transmitter. The impairment consists in clipping of sidebands and distortion of the env...
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The impedance of some broadcast antenna arrays varies so much over the transmitted band as to impair the performance of the radio transmitter. The impairment consists in clipping of sidebands and distortion of the envelope at high modulation frequencies. This paper reports on an experimental determination of the nature and magnitude of this impairment and on its substantial reduction by suitable coupling methods.
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