Signal Transmission Line Research Articles

希薄気体を用いることによる脈動流の信号伝達の特性改良

The pipe as a fluid signal transmission line has many natural frequencies of the first, the second, …that depend on its length. At those frequencies, the amplitude of the signals shows peaks. For this reason it is difficult to operate ac fluidics in wide frequency range.In this study, rarefied gas was used to improve the characteristics of the transmission of pulsating fluid signals by removing the defects of the amplitude change by the resonance as stated above. This principle is as follows; The viscosity of gases is independent to the pressure and the density is proportional to the pressure, then the kinematic viscosity will become large in rarefied gases, and as a result, the peaks of the amplitude at the resonant frequencies are reduced.In carrying out this experiment, fluid amplifiers and a sinusoidal fluid signal generator were placed in a closed vessel, and their supply ports were opend to atmospher, and then the pressure of the vessel was lowered by a vacuum pump. The experimental results showed that the effects of the resonance could be reduced considerably at the pressure as less as 0.1×105[Pa].The frequency characteristics of the transmission lines were well explained by the distributed parameter theory which was modified to apply for the pulsating fluid signal with do flow.

地震計による山鳴り現象計測装置について

The observations with the seismometer at Sunagawa Coal Mine started as the study entrusted from Coal TechnologyResearch Institute in 1971. Then processing and analyzing system owned by Coal Technology Research Institute were removed to Horonai Coal Mine in June 1980. So that, at this coal mine, we had recorded on only pen-recorders.But meanwhile the credibility of systems was lost extremely because it became difficult to record on a pen-oscilograph owing to inferiority of signal transmission lines and increase of noises. In this time the hydraulic mining blocks were shifting to 860L, we had to enrich the measuring instruments of seismic events for the purpose of strengthing safety. The recording on penoscilograph became more correct as a result of carring out immediately strengthing and renewing the signal transmission lines and decreasing noises.We tried the automatic of signal processor after the improvement of signal transmission system. The system owned by Coal Technology Research Institute was so excellent as corresponding to academic study, but in this coal mine, we planed to simplify the obtained data by means of the minimum processing i.e. a seismic source location and magnitude calculation. So that we made for the system to operate easily as one of centralized supervision.In regard to the processing system, two microcomputers display their abilities which are equivalent to a minicomputer by connecting them in series. The former is in use for sampling the data and the latter for operation and controling peripheral equipments. We order the measuring instruments from electric works, and they are controled in our own program. It is easy for us to operate it in our place of work.

Analysis of transmission-line signal distribution to multiple ports

The frequency response of a characteristically terminated transmission line, with multiple lumped discontinuities (output port loads) along the line, is determined. The analysis applies steady-state transmission-line solutions and simple circuit analysis methods in an iterative manner to determine the frequency response of each output port. This method is applied to the case of equally spaced capacitive reactance impedances along the transmission-line length. The phase and amplitude distortion resulting from line losses and output loading are determined.

A New Type of Ion-Selective Device

Specific ions in solution can be determined potentiometrically with ion-selective electrodes. With conventional electrodes the high electrical resistivity of the solid membranes necessitates the use of high-impedance voltmeters and shielded cables. Here we report on a new ion-selective electrode where amplifier electronics has been integrated in the sensor head, whereby the membrane response is transformed into a low-impedance output signal. The MOSFET input stage of the amplifier provides an input resistance of up to 1012 ohm, allowing the use of solid inner contacts on the membranes in most cases. With this electrode the requirements for the registration equipment and for the signal transmission lines and size are relaxed considerably, providing advantages in terms of low cost, miniaturization, computer compatibility and remote sensing ability.

Application of Fluidic Elements for Realizing Ternary Functions

Normally, when setting up industrial control systems, a two-valued (binary) logic is used. Under certain conditions, however, equipment expenditure for signal processing may be cut down by using a three-valued (ternary) logic. The paper deals with the most important ternary functions and their characteristics. Realization of these functions, equipment-wise, is illustrated by the diaphragm and pure fluid elements of the DRELOBA pneumatic control system. In conclusion, an embodiment is described giving evidence of the fact that savings in circuit elements and signal transmission lines may be achieved by using the ternary logic as compared with pure binary circuits.

Application of the small-signal transmission line equivalent circuit model to the a.c., d.c. and transient analysis of semiconductor devices

It is shown that the use of the small signal transmission line equivalent circuit model is not restricted solely to the small signal a.c. analysis of semiconductor devices. Simple algorithms are described which allow it to be used to compute the d.c. and the large signal transient properties of semiconductor devices to any desired precision. The approach is demonstrated by computing the a.c., d.c. and transient properties of an N + P junction diode.

Data Highway System in Iron and Steel Works

Recently, the scale of a works has become larger in every industries and information flow in the works has been more complicated.For example, an iron and steel works consists of blast furnaces, basic oxygen furnaces and rolling mills, where computers are installed for various controls. The raw materials and the products of each process must be weighed and analized, then the data must be sent to the computer immediately.In other words, it is necessary that measured data at random time series are transmitted on line from a data source point to a computer. So far, one to one direct wiring system has been adopted, but applying this manner to the whole works will result in such disadvantages that the total wiring length extends to several tens of kilometers, the interface device at each station becomes more complicated and expensive, and further, the new station requires new cables.Several conventional systems, time-division or frequency division, and centralized or looped, were compared and we decided to apply a new system.This paper describes the data transmission system so called “Data Highway System”, which is designed specially in order to improve the former disadvantages and becomes much more economical, flexible and reliable.This system has, at first, an ability to transmit the data between two stations directly without a special central processor such as a computer for data multiplexing. Sending stations and receiving stations are connected in loop by coaxial cables. The signals consist of receiver address, sender address and data, and are sent on the transmission line. Each station can decode address part and catch its own signal from the signal train on the loop.Secondly, the data from many stations are sent simultaneously in time-division manner, consequently, one signal transmission line is sufficient to the traffic capacity. From these points, this system has much more economical advantages, for example, the wiring length is reduced to under one-tenth.Thirdly, this system has higher reliability on account of several unique methods of checking and monitoring.This system is applied to the data communication among iron and steelmaking processes at the Fukuyama Works of Nippon Kokan.

Broad-band thin-film signal sampler

Previous developments in high frequency signal sampling have been extended by applying thin-film and solid state techniques to the sampler design. The basic elements of a sampler are a signal-carrying transmission line, a sampling gate, a drive line for the gate pulse, and a video output. In the design reported here, a thin quartz substrate supports the circuits. To reduce signal-line reflections the gate is made the center element of a low-pass signal-line filter. The gate pulse is developed across a length of slot transmission line in the signal ground plane parallel to and beneath the signal transmission line. A beam-lead Schottky diode pair is mounted across the slot with its center node connected to the signal transmission line through the substrate.

Signal Transmission Line with Low Attenuation and Wide Frequency Passband

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Multiple Reflections on Pulse Signal Transmission Lines-Model for Computer Solution

A mathematical model for multiple reflections on lossless, distortionless signal transmission lines is developed for step changes in voltage or current at the source. The model is quite general and is valid for a source driving either one or two lines each loaded with an arbitrary number of discontinuities at arbitrary distances. It will give an exact solution for discontinuities and terminations which are purely resistive and allows for resistances of any size, none of which need be alike. Although an exact solution is valid only when the capacitances are negligible, a method is presented which will partially compensate for a capacitively distorted wave if the capacitive-characteristic resistance time constant is reasonably small compared to the transit time of the line. Considerations for digital computer simulation of the mathematical model are discussed and several examples including open backplane wiring comparing actual and computer results are given. The model and simulation are especially useful for lines which are not terminated in the characteristic impedance at the source or load end and also where modification of the model can be made to investigate reactive and nonlinear terminations.

The Development of an Acoustical Thermometer for a Graphite Matrix Nuclear Fuel Element

The development of an acoustical thermometer for use in graphite matrix nuclear fuel elements is described. Test results indicate that this thermometer accomplished the objective of automatically, accurately, and reliably recording temperatures of a number of sensors. The acoustical thermometer system offers a wider choice of signal transmission line and sensor materials than conventional thermometer systems, since it does not require the use of electrical insulators or the conductors in them. This advantage was the main reason for choosing the acoustical thermometer for use in the particular environment of interest. While the development of the thermometer was directly aimed at the solution of problems associated with a nuclear and carbonaceous environment, a number of observations are presented that should be pertinent to acoustical thermometer design in general.

A Unified Theory of Electron Beam Interaction with Slow Wave Structures, with Application to Cut-off Conditions†

An analysis is given of slow wave structures coupled to electron beams, which is based on their resonant properties rather than their traveling wave properties. Thus the analysis is particularly appropriate for narrow band slow wave structures. The fields of a general symmetrical cavity chain are expanded in a set of solenoidal and irrotational short-circuit modes, defined within electric shorting planes on the coupling surfaces. The amplitudes of the modes are evaluated in terms of the beam current and tangential electric field on the coupling surfaces. The latter field is expanded in a set of open-circuit modes which amplitudes are related back to those of the shortcircuit modes with the aid of a Variational Principle. Alternately, the fields of a cavity are expanded in a set of open-circuit modes, driven by the beam current and by tangential magnetic field on the coupling surfaces. This latter field is expanded in a set of short-circuit modes, which amplitudes are related to the open-circuit mode amplitudes with the aid of the Variational Principle. The accuracy of the procedure is verified for a narrow passband by proving the relation power flow equals stored energy times group velocity. It is possible to prove the equivalencemore » of the dispersion relations for a cold structure obtained from the short- and open-circuit mode expanstons. Small signal transmission line equations are obtatned for a longitudinally confined beam, including relativistic effects, under the action of cavity solenoidal electric field and space charge irrotational field. Analysis is applied to a study of the beam-circuit interaction when the slow space charge beam mode is nearly synchronous with the cold circuit near the latter's cut-off. This is the situation which often leads to oscillations in high-power structures, interfering with their operation at a lower frequency. On a small-signal basis, four waves exist, two of constant amplitude and a pair of growing and decaying waves. The cut-off oscillations, which exist in a relatively wide voltage range such that the slow beam mode is in synchronism with the cold circuit near the cut-off, are attributed to the presence of the growing wave of forward circuit power and negative beam power. As the voltage is lowered (in a structure of forward group velocity from zero to pi phase shift), the negative power of the growing wave changes to positive power at about the condition marking the boundary of the cut-off oscillations. As the voltage is lowered further, two constant amplitude waves of negative beam power appear, enabling backward wave oscillations to exist within a narrow voltage range. This distinction between cut-off oscillations and backward wave oscillations should be made in the general class of slow wave structures.« less

Transverse-Field Traveling-Wave Tubes with Periodic Electrostatic Focusing

Traveling-wave tubes are described in which the wave-propagating structure constitutes a smooth, balanced transmission line for radio frequency signals while at the same time providing a space-periodic focusing field at zero frequency. Experimental structures for the 500-900 mc band have wave velocities of 1 to 2 per cent of light and characteristic impedances of about 500 ohms. A simplified theoretical analysis is given, based on the readily visualized concept of transverse electron waves in a focusing field. In order to get gain, the electron stream must travel faster than the circuit wave by a substantial margin which is determined by the strength of the focusing field. The gain is proportional to the square root of the beam current. Experimental data are presented concerning the relation between focusing field and effective beam velocity, and between beam current and gain. They are in good agreement with the theory. Noise figures as low as 6 db have been measured.