摘要:

AbstractIn synthesizing RC filters by simulation of LCR filters, the advantages are simplicity of synthesis and low element sensitivities. Ordinarily, the operational amplifiers used in this synthesis method are all considered to have ideal characteristics which hold only at low frequencies. Researches on the effect of the frequency characteristics of the operational amplifiers on the filter characteristics have been done for Biquad circuits in several cases but none at all for higher‐order active RC filters. In this paper, first, a synthesis method different from the conventional method is shown for a filter with finite zeros. Then a method for reducing the effect of the finite GB product on active RC filters is shown by contradicting the unnecessary phase‐rotating component of the operational amplifiers with the entire circuit, assuming that all operational amplifiers used in the filter have the same GB product. Furthermore, actual circuits are synthesized and experiments are performed. As a result, the effectiveness of the proposed compensation technique is shown by the fact that the frequency range for possible synthesis is extended. Finally, a synthesis method and experimental results are shown for a filter with all po

ISSN:8756-6621    

DOI:10.1002/ecja.4400670102

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper combines the supplementary variable method and the phase method to analyze the steady‐state of GI/Ek/1 with finite waiting room. Although there have been many studies made on the queue with finite waiting room, there has not been a study of GI/Ek/1which determines the characteristic quantities and discusses the characteristics by numerical computation. This paper defines first the residual arrival time as the supplementary variable and derives steady‐state basic equations for the joint probability density functions of that variable and the total remaining number of phases in the system. Using Laplace transform, the solutions are represented by the joint probability densities for the remaining number of phases and the zero remaining arrival time. the value of joint probability densities is determined, if the distribution function of arrival interval is given, by solving a system of linear equations by numerical computation. Using that solution, various characteristic quantities are represented such as number of customers in the system, actual waiting time, response time, distribution of busy period length, distribution of idle period length, loss probability and power. Finally, the analytical result for GI/M/1/N is found to be equal to the known result, and as a numerical example characteristic quantities of GI/E4/1/4* are illustrated, together with the discussion for the characterist

ISSN:8756-6621    

DOI:10.1002/ecja.4400670103

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractRecently, for the improvement of reliability of digital communication systems, various kinds of error‐correcting codes are being used. to improve system reliability through the use of more capable error‐correcting codes it is extremely important to simplify the decoder construction and to reduce the decoding delay. This paper studies a decoding algorithm for a class of simple iterated codes (SI codes) constructed by simply repeating I times a codeword (called block) in a given code (called subcode). Moreover, this paper discusses the decoding delay when this decoding algorithm is applied to decoding the Reed‐Muller codes constructed by the superimposing m

ISSN:8756-6621    

DOI:10.1002/ecja.4400670104

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThis paper proposes a technique for designing a large class of two‐dimensional recursive digital filters. A mapping technique is used to design weakly causal digital filters. the design is based upon minimization of the sum of squared differences between the desired and actual two‐dimensional impulse responses over a finite interval. the filter is designed in terms of a canonic form state‐space model. the proposed technique has the advantage of simplicity and is applicable to the design of quarter‐plane digital filters as well as symmetric half‐plane digital filters. the test of stability for such filter

ISSN:8756-6621    

DOI:10.1002/ecja.4400670105

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractRecently a few studies have been made of distributed coupled‐line type digital frequency multipliers which multiply the repetition frequency of a square input wave. the transfer functions of an n‐section distributed coupled‐line constant‐resistance network and an n‐section distributed‐constant bridged‐T network have the form of a rational function of order n with respect to delay operator z−1. We develop our discussion on the basis of this transfer function. the theory is developed for the coefficients of the rational function and the output response in a stationary state can be determined by the coefficients of both the denominator and numerator. the obtained results can be applied to all networks having the transfer functions treated in this paper, but the detailed realization condition for each individual network is not discussed. the experiments and calculations shown in Figs. 4 ‐ 7 are conducted using the distributed coupled‐line constant‐resistance network as an application example. the network described here can be a digital frequency multiplier for two incident impulse trains, 1111 and 1‐11‐1. the behaviors of the multiplier in the frequency domain as well as in the time domain are investigated and it is shown that a faster impulse train can be obtained at the output in the time domain by adequately thinning out the discrete frequency components of t

ISSN:8756-6621    

DOI:10.1002/ecja.4400670106

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractA monopole antenna with ground wires excited at the terminal between the vertical and several ground wires is analyzed by varying the length of the vertical element, the lengths and numbers of ground wires and their angles of inclination. the characteristics of the structure are analyzed for an antenna with a quarter‐wavelength monopole element on a perfectly conducting ground plane. In the numerical analysis the effect of the feeder is neglected and a Hallen‐type integral equation with a simplified kernel is used. In the experiment the center conductor of the coaxial feeder is connected to the monopole and the outer conductor is connected to the ground wires. the effect of a sperrtopf, which prevents leakage current from flowing on the outer conductor, is studied. From the analytical results it is found that the gain of the monopole antenna with ground wires does not exceed that of a half‐wave dipole even if the length of the monopole is made about a quarter wavelength and the ground wires are directed 60° downward. When the antenna is on a perfect ground plane, the directivity strongly depends on the distance between the feed and the conducting plane and becomes maximum when the distance is about 0.3 wavelength. When the ground wires are 0.2 wavelength long and the angle of inclination is 300 the antenna is matched with a 50‐Ω feed line and the gain bec

ISSN:8756-6621    

DOI:10.1002/ecja.4400670107

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractThe wave normal directions of magnetospheric VLF/ELF chorus have been determined by using data from the geostationary satellite GEOS 2. They will provide useful information on the emission generation mechanism.

ISSN:8756-6621    

DOI:10.1002/ecja.4400670108

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractTwo perpendicular arrays of optical fibers are combined with a spherical lens and cylindrical lenses to form a 2‐dimensional‐velocity sensor. Each fiber array picks up spatial frequency components of the object pattern, and the center frequency of the narrowband output signal gives a velocity component of the object parallel to the optical fiber array. Therefore, velocity of the object is determined from center frequencies of the signals from the two fiber arrays. the equivalent filter including the imaging system is derived and its spatial frequency selectivity and accuracy of the measured velocity are clarified. the accuracy can be set to the desired value by properly adjusting the parameter values describing this system. the validity of the present system has been confirmed experimenta

ISSN:8756-6621    

DOI:10.1002/ecja.4400670109

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractElectroformed silver thin films exhibit reversible switching in wet air at atmospheric pressure. It was proved that the switching is due to the breakdown and the immediate restoration of conductive silver filaments. the mechanism of the restoration of conductive filaments is a dendritic silver growth through electrochemical reactions. Adsorbed water onto the surface of the thin films is essential in the process of the restoration of the conductive filaments, i.e., in the mechanism of the reversible switching. Mechanisms of the conduction at the ON and the OFF states and the breakdown of the conductive filaments also are discussed.

ISSN:8756-6621    

DOI:10.1002/ecja.4400670110

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY

摘要:

AbstractConsiderable effort has recently been devoted to the development of monolithic, integrated‐circuit (IC) analog‐to‐digital (A/D) converters. However, the accuracy of successive‐approximation A/D converters has been limited to 10 bits due to the linewidth variations in the state‐of‐the‐art IC processing. Higher accuracies up to 12 bits have been realized only by trimming passive elements. In this paper, an A/D converter with an inherent (on‐chip) “self‐compensation” circuit is proposed which enables high‐accuracy analog‐to‐digital conversion without trimming. the principle and circuit construction of the new A/D converter are described. Fabrication and characterization of an experimental device are also discussed.The circuit described is a successive‐approximation MOS A/D converter, in which the input charge stored on a capacitor array is redistributed over the capacitors. the errors in the capacitances are evaluated prior to the conversion step using the array itself as a reference. the correction charge is generated automatically during the redistribution step, referring to the correction data. Charge correction is done simply by applying an appropriate voltage to a correction capacitor which is added to the array. This simple circuit is easy to build using a monolithic IC technology. A 3 μm CMOS IC technology was used to fabricate experimental circuits to build a 14‐bit A/D converter. Performance evaluation of the circuits demonstrates that the method proposed here has reduced the linearity erro

ISSN:8756-6621    

DOI:10.1002/ecja.4400670111

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1984

数据来源: WILEY