摘要:

AbstractThe CAD method for Norton transformation is presented. Norton transformation has been considered as an important process in the reactance bandpass filter design. It is an equivalence transformation process for easy realization of the element of practical filter. The previous method requires certain designer experience and determines the optional element values by iteration and human interaction. This paper presents a method in which the research method is done by random number and no designer experience is ever required. This method conducts Norton transformation automatically. It has made it possible to automate the complete engineering design of the filter. First, the Norton transformation is outlined, the method giving the circuit topology convenient for program is discussed, and based on the method for topology the algorithm is presented. Finally, how to choose several parameters will be investigated for the search method for several examples. Also given is the design example presented in the computer output.

ISSN:8756-6621    

DOI:10.1002/ecja.4400630502

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

年代:1980

数据来源: WILEY

摘要:

AbstractIn the study of nonlinear oscillations, it is well known that, in general, the fundamental harmonic solutions are either in phase with the external force or in opposite phase with it in a lossless system represented by a second‐order differential equation for a single external force. This paper considers a system with asymmetrical restoring force for several external forces. In the following steps, it is shown that there exist solutions in this system which are neither in‐phase nor in opposite phase with the external forces. First, we consider a second‐order system with an asymmetrical restoring force composed of two line segments as an asymmetrical system, and obtain a periodic solution in the same way as in the case of a single external force. The stability of the obtained periodic solution is studied by using Hill's equation and the boundary conditions of the stable and unstable regions are shown clearly. Moreover, the branching phenomena in the boundary are analyzed in four cases. In three of these four cases, there are branching or jump phenomena of the harmonic solutions of fractional orders (2n + 1) /2 (n = 0, 1, 2) due to asymmetry as in the case of a single external force. However, the fourth case shows the branching phenomena of periodic solutions which are neither in‐phase nor in opposite phase with the external forces. The results of numerical analysis and the appropriateness of the analysis ar

ISSN:8756-6621    

DOI:10.1002/ecja.4400630503

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe coefficient matrices of the describing equations for the passive switched‐capacitor (SC) networks consisting of periodically open/closed switches, capacitors and independent voltage sources can be obtained by using new topological formulas. These topological formulas are derived when the open/close resistances (R, r) of the switch are taken into account, by taking the limit of (R, r) → (χ, 0) for the coefficient matrices of the Laplace‐transformed differential state equations describing the networks. This method differs from the previously used nodal method, in that it does not need matrix inversion calculation so as to express the coefficient matrices in terms of powers of matrices which are simply obtained topologically. It is extremely useful for analysis of the large‐scale passive SC

ISSN:8756-6621    

DOI:10.1002/ecja.4400630504

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

年代:1980

数据来源: WILEY

摘要:

AbstractIn general, it is known that if the stationary characteristics of a PPL, phase‐locked loop, are improved, its transient response characteristics are deteriorated, while if the transient response characteristics are improved, its stationary characteristics are deteriorated. The DPLL, digital PLL, is not an exception in regards to the features.Here, we will realize a loop which is superior both in the effective phase error and the average transient response time compared with conventional DPLL with less deterioration of the average transient response time caused by improved effective phase error, due to inserting AND filter to the conventional binary quantized DPLL. The characteristics of the proposed loop are analyzed theoretically by use of the Markov chain and confirmed to be identical by computer simulation. These results prove that the proposed loop has better characteristics than the conventional one

ISSN:8756-6621    

DOI:10.1002/ecja.4400630505

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

年代:1980

数据来源: WILEY

摘要:

AbstractAs the demand for calls by subscribers in communication networks increases, it is necessary to have sufficient equipment or a high‐degree of control over the communication network to make immediate connection of the calls to the desired parties by subscribers at any time they desire. However, economically, it is impossible in large‐scale, modern communication networks to provide enough equipment for all traffic fluctuations. In this paper, a measure of “abnormality” representing the degree of the fluctuations of the subscribers' demand is used to ensure the connection of the calls by limiting all traffic fluctuations below a specified abnormality. First, for the traffic pattern representing the subscribers' demand, we derive a theoretical formula and an approximate calculation method for the traffic intensity which the communication network must actually carry, taking into consideration the number of subscribers.Then we calculate the traffic intensity which each equipment must carry in a communication network using a relatively simple method of route selection. We present a method for obtaining a maximum value for the traffic pattern below a specified abnormality. It is adequate enough to provide a sufficient number of equipment for the traffic intensity to be carried. It may be possible by this design method to have a very efficient reinforcement of the equipment for traffic fluctuations by a limited equipment inv

ISSN:8756-6621    

DOI:10.1002/ecja.4400630506

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

年代:1980

数据来源: WILEY

摘要:

AbstractIn realizing high‐efficiency, high‐speed digital transmission systems, waveform distortion due to amplitude and phase distortion is a definite impediment. This paper proposes a phase equalizer using a constant‐resistance stripline directional coupler as its basic circuit. Unlike phase equalizers realized with lumped inductors and capacitors, the proposed equalizer offers excellent frequency response over a range from DC to 1 GHz. It is shown that the equalizer is equivalent to a transversal filter realizable in the time domain, which simplifies its structure. Experimental results are shown to match the theoretical results using a prototype equalizer implemented with thin‐film hyb

ISSN:8756-6621    

DOI:10.1002/ecja.4400630507

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe shielded cable with close inner conductors is different from the conventional local cable and can be applied to directional couplers. In this paper, for the purpose of obtaining tight coupling, we investigated the cable in which two inner conductors are very close. In particular, we consider the finishing with very fine conductors for small power application. In this case, it is necessary to use a second dielectric in order to maintain the space between the inner conductors, resulting in an inhomogeneous media. For the solution of such a shielded cable pair by quasi‐TEM mode approximation, we use the method of conformal mapping. Also, the measurements of the cable constants and the restrictions of a directional coupler by TEM approximation are described. The approximate equations obtained are applicable to the design of a cable with tight coupling below about 10 dB and the trial production of 3 dB‐ and 5 dB‐cables was proved to be satisfactory. The directional couplers using these cables are possible in practice and we expect to see their application in the VHF and UHF

ISSN:8756-6621    

DOI:10.1002/ecja.4400630508

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe step electrode transistor or GaAs Schottky‐barrier field‐effect transistor can oscillate above 6 GHz. A high Q and good temperature‐property dielectric resonator has been developed. Due to the microwave transistor and the dielectric‐resonator, the frequency stability can be made superior and noise characteristics better in the microwave oscillator, and integrable oscillator can be obtained. For the microwave oscillator design, the output power, stability, tunability and noise characteristics must be known. Therefore on using the negative‐resistance of the microwave transistor and transmission type of dielectric resonator, operation is analyzed for the oscillator using the transmission‐type dielectric‐resonator taken as an out‐of‐band resistive termination. First, changes of the oscillation power and frequency at the center frequency due to the negative resistance property are clarified; the frequency stability and oscillation power variations with the resonance frequency spread are considered; also clarified is the relation between the frequency stability and tunability. Finally, the noise comparisons among the above transistors and other solid‐state devices in the 7‐G

ISSN:8756-6621    

DOI:10.1002/ecja.4400630509

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

年代:1980

数据来源: WILEY

摘要:

AbstractA simple formula is derived to estimate the asymptotic field diffracted by an infinitely long cylindrical object with an arbitrary cross section when an arbitrary cylindrical wave with directivity is incident. In the analysis, the problem of diffraction of a cylindrical wave by an infinitely long slit is formulated by means of the Kobayashi‐Nomura method, and an asymptotic series solution is derived with respect to the distances between the source and the scatterer and between the scatterer and the observation point. The solution is given in the form of a diffraction pattern function for the plane wave incidence and its derivative. The method is applicable to any diffraction (or scattering) problems of the object for which the pattern function is known. The result is applied to the problems of diffraction by a half‐plane and a wedge and of scattering by a circular cylinder, and practical representations are derived. For the half‐plane problem, the results are compared with those derived by other methods and complete agreement is confirmed. Numerical calculations for the slit diffraction problem and scatterings from the cylinder result in accurate results even when the distance between the object and the source is extremely small, as long as the second or the third term is taken into consideration. The method is believed to be an effectiv

ISSN:8756-6621    

DOI:10.1002/ecja.4400630510

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe rapid growth of telecommunication networks has brought about diversified applications. This trend will become clearer as these networks become integrated service networks. To control and operate the networks efficiently, necessary actions should be taken to measure traffic flows as precisely and as soon as possible.In general, since actual communication traffic is time‐varying in its parameters, such as the call occurrence rate, requirements are needed for measuring these traffic variations in connection with analysis of traffic‐varying trends, detection of abnormal traffic, traffic prediction, and others. Therefore, this paper investigates an estimation method of time‐varying traffic parameters with the help of a filter. First, we construct a non‐stationary stochastic model of estimated objects and study the estimation accuracy with which the time series data obtained through the stochastic process measurements provide estimates of time‐varying parameters after filter processing. Second, we introduce the optimum filter which minimizes the estimation error, based upon the above analyses. Third, we show some examples of applications, i.e., estimation of varying call occurrence rates and detection of abnormal traffic, both of which are made using t

ISSN:8756-6621    

DOI:10.1002/ecja.4400630511

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

年代:1980

数据来源: WILEY