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CONTINUOUSLY SCALED TRANSMISSION LINES WITH APPLICATIONS TO LOG-PERIODIC ANTENNAS

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 1969年第1期AP17卷 2-&页

作者： JONES, KE MAYES, PE University of Illinois Urbana-Champaign IL USA

The results of several studies on network models of log-periodic structures are described. A nonuniform, continuously scaled transmission line is introduced to simulate the near-field behavior of the log-periodic dipole array. The frequency-independent performance of the continuously scaled line represents the ideal, which is approximated by using lumped elements in a log-periodic structure. It is particularly significant to note that 1) the continuously scaled model predicts the observed input impedance behavior of log-periodic dipole arrays even when the frequency is approaching the high-frequency limit of the antenna, 2) phase velocity on the transmission line model in the active region and at the input region is also found to agree with experimental data, 3) increasing the Q of the loading element increases the coupling to the reflected wave, resulting in increased variations of impedance. Decreasing the angle of taper of the antenna will compensate for the increase in Q . Based on this model, it is shown that true size reduction may be achieved only at the expense of efficiency.

关键词： Log periodic antennas Frequency Transmission line theory Impedance Dipole antennas Geometry Predictive models Voltage distributed parameter circuits Loaded antennas

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Anti-parallel operation of four high-efficiency avalanche diodes

Anti-parallel operation of four high-efficiency avalanche di...

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IEEE International Conference on Solid-State circuits (ISSCC)

作者： H. Kawamoto RCA Laboratories Limited Princeton NJ USA

A new method of combining the power output of an even number of high-efficiency avalanche diodes will be described. Four diodes operated in a microstrip circuit have generated a power of 620 W at 1.026 GHz.

关键词： Diodes Radio frequency Pulse generation Power generation Power transmission lines Transmission line theory Microstrip Coupling circuits distributed parameter circuits Microwave theory and techniques

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Computer Analysis of Microwave Integrated Switches

Computer Analysis of Microwave Integrated Switches

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Microwave, MTT-S International Symposium

作者： H.E. Stinehelfer Microwave Associates Inc.

The circuit analysis of microwave networks composed of distributed transmission lines and lumped circuit elements soon become complex when the transmission lines employed have significant loss that must be considered. The many possible combinations of Iumped circuit parameters and the use of shorted and open stubs to form resonant circuits useful for the control of microwave energy make it very necessary to use the computer to do the complex calculations for circuit analysis. Such a program must contain the possibility then for the user to specify not only the network numerical values but the way in which these network components are connected. In general the characteristics of a network can be computed from its ABCD matrix. The specification of a network is then broken down into its simplest form called a SECTION, each SECTION being specified by eleven parameter values or circuit TYPE designations. When each SECTION is so specified the computer calculates the transfer ABCD matrix for this section of the network and combines this matrix to the preceding SECTIONS by matrix multiplication before considering the next section of the network. A Flow Diagram for the computer program is shown in Fig. 1. After the first data card containing a name and number for indentification is read the input data for the first case or problem is read. The computer then prints out the titles and input data so specified for the user to check the parameter values and control TYPE numbers given in the data. The specified parameter changes are made in the SECTIONS designated and a set of changes called the VARIABLE is made to the network. The VARIABLE becomes the horizontal axis for plotting the characteristics of the network and the parameter changes generate a family of curves for the network analysis. After each change in the VARIABLE the ABCD matrix is calculated and/or stored in core for later plotting. After all changes in the VARIABLE and parameter are complete, a tape is generated to

关键词： Transmission line matrix methods distributed parameter circuits Microwave circuits RLC circuits Circuit analysis computing Computer networks Character generation Switches Circuit analysis Propagation losses

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The WLW 500-kilowatt broadcast transmitter

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PROCEEDINGS OF THE INSTITUTE OF RADIO ENGINEERS 1934年第10期22卷 1151-1180页

作者： Chambers, JA Jones, LF Fyler, GW Williamson, RH Leach, EA Hutcheson, JA Crosley Radio Corporation RCA Victor Company Inc. General Electric Company Westinghouse Electric and Manufacturing Company

In this paper the design, installation and, performance of the highest power broadcast station at present in America is described. Considerations underlying WLW's decision to increase power are mentioned. The station is unique in a number of respects, the most outstanding being the high level class B modulator producing audio-frequency outputs of 350 killowatts, the "isolation" operation of the control circuit, and the concentric transmission line. The vertical radiator is pictured and data are presented comparing its performance to that of a standard T antenna immediately adjacent. The more important performance characteristics of the transmitter and antenna are given.

关键词： Radio transmitters Transmitting antennas Radio broadcasting Receivers High power amplifiers Power transmission lines distributed parameter circuits Maintenance engineering Power engineering and energy

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A Versatile Power-Line-Carrier System

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Transactions of the American Institute of Electrical Engineers 1944年第3期63.0卷 129-133页

作者： Lensner, H.W. Singel, J.B. Westinghouse Electric and Manufacturing Company Baltimore Md. United States

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Elimination of phase shifts between the currents in two antennas

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PROCEEDINGS OF THE INSTITUTE OF RADIO ENGINEERS 1934年第3期22卷 374-394页

作者： Roder, H Gen Eelct Co Gen Engn Lab Schenectady NY USA

If two antennas (vertical radiators) are fed through transmission lines from a common radio-frequency supply, then phase shifts between the currents in these antennas will occur if one antenna varies in capacity or resistance. This will result in a change of the horizontal radiation pattern. As shown in the following paper these phase shifts can be eliminated by a certain method of tuning the antenna circuits. The degree of phase compensation attainable, however, depends on the attenuation of the transmission line. Compensation of phase shifts is also possible if an artificial line is inserted at the sending end for reasons of making the effective electrical length of the transmission line any value desired. The results of the experimental investigation were found to be in good agreement with the theoretical analysis.

关键词： Transmission line antennas Transmission line theory Antenna radiation patterns distributed parameter circuits Radio transmitters Antenna accessories Antenna feeds Broadcasting Phased arrays Directive antennas

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AN ACCURATE CALCULATION OF UNIFORM MICROSTRIP TRANSMISSION LINES

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IEEE JOURNAL OF SOLID-STATE circuits 1968年第2期SC 3卷 101-+页

作者： STINEHELFER, HE Microwave Associates Inc. Burlington MA USA

An analytical program for calculating the field distribution about a microstrip transmission line bounded by a shielding wall is used to calculate the impedance, velocity, and attenuation parameters. The program input parameters are the dimensions of the strip and shielding wall and the relative dielectric constant of the substrate material. The field distribution about the strip is integrated to find the charge density on the strip and walls with and without the dielectric substrate. From these two calculations, the relative velocity and impedance can be calculated.

关键词： Transmission lines Impedance Strips Dielectric substrates Transmission line theory Microwave transistors Dielectric materials distributed parameter circuits Microstrip components Conductors

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General Synthesis of Quarter-Wave Impedance Transformers

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IRE Transactions on Microwave Theory and Techniques 1957年第1期5卷 36-43页

作者： Riblet, Henry J. Microwave Development Labs Wellesley Mass. United States

This paper presents the general synthesis of a radio frequency impedance transformer of n quarter-wave1steps, given an “insertion loss function” of permissible form. This procedure parallels that of Darlington for lumped constant filters by providing the connection between Collin's canonical form for the insertion loss function and Richards’ demonstration that a reactance function may always be realized as a cascade of equal length impedance transformers terminated in either a short or open circuit. In particular, it is shown that insertion loss functions of the form selected by Collin are always realizable with positive characteristic impedances, and that the synthesis procedure, for maximally flat and Tchebycheff performance, involves the solution, at most, of quadratic equations. In addition, this procedure permits the proof of Collin's conjecture that, for his insertion loss function, the resulting reflection coefficients are symmetrical. Finally, closed expressions are given for the coefficients of the input impedance of a given n section transformer in terms of the n characteristic impedances and vice versa. Copyright © 1957 — The Institute of Radio Engineers, Inc.

关键词： Impedance Transformers Insertion loss Reflection Filters Performance loss Equations Radio frequency Circuit synthesis distributed parameter circuits

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REFLECTION AND CROSSTALK IN LOGIC CIRCUIT INTERCONNECTIONS

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IEEE SPECTRUM 1970年第7期7卷 44-&页

作者： DEFALCO, JA Honeywell Inc. USA

Digital logic circuits are now available and are being used with delay times that are comparable to the delays of interconnections used in packaging these circuits. At high speeds, however, such interconnections no longer behave as simple short circuits, but take on the appearance of transmission lines. Unless transmission lines are terminated properly, ``reflections'' can develop that might be of sufficient magnitude to produce false logic levels or exceed maximum circuit voltage specifications. One may choose to solve the problem by increasing the density of the system. This, however, introduces the problem of ``crosstalk.'' The present article describes several analytical techniques for predicting the kinds of reflections and crosstalk that are typically seen in digital systems, thus enabling the engineer to determine in advance whether or not such ``interconnection noise'' will result, how bad it will be, and what the typical interconnection limitations are for circuits of various speeds.

关键词： Crosstalk Logic circuits Integrated circuit interconnections Delay distributed parameter circuits Packaging Voltage Acoustic reflection Digital systems Circuit noise

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The Synthesis of Nonuniform Lines of Finite Length—Part I

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IEEE Transactions on Circuit Theory 1967年第4期14卷 394-403页

作者： Heim, Dwight S. Sharpe, Charles B. Radar and Optics Laboratory University of Michigan United States Radar and Optics Laboratory Department of Electrical Engineering University of Michigan Ann Arbor Mich. United States

The class of lossless, nonuniform transmission lines having an absolutely continuous characteristic impedance is considered. It is shown that an integral representation for the solution of such a line is possible when the line is terminated in a matched load. The principal contribution of this paper is the derivation of a linear integral equation in the kernel function of this representation. It is shown that the solution to this integral equation constitutes a unique solution to the synthesis problem for lines of the class considered. Necessary and sufficient conditions for realizability are also given. © 1967 IEEE. All right reserved.

关键词： Impedance Integral equations Laboratories Sufficient conditions Laser radar Optical scattering Optical reflection Propagation losses distributed parameter circuits Kernel

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