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This paper presents novel design procedures for class E switching circuits allowing implicit circuit equations. Because of the allowance, circuit simulators can be used in the proposed design procedures. Moreover, the proposed design procedures also allow any conditions considered until now. The proposed design algorithms are implemented by using PSpice and OPTIMUS. This paper shows the design examples of two kinds of class E switching circuits. In particular, the design example of the class E oscillator shows the benefit of the proposed design procedure eminently, i.e., it is unnecessary to make an equivalent model of the semiconductor devices for the design. These design examples show the validity and effectiveness of the proposed design procedures. Index Terms--Class E switching, computer-aided design, initial conditions, Newton's method, OPTIMUS, PSpice, steady state.

This paper presents a novel class of cellular neural networks (CNNs), where output of a cell in the CNN is given by the piecewise-linear (PWL) function having multiple constant regions or a quantization function. CNNs with one of these output functions allow us to extend CNNs to image processing with multiple gray levels. Since each cell of the original CNN has the PWL output function with two saturation regions, the image-processing tasks are mainly developed for black and white output images. Hence, the proposed architecture will extend the promising nature of the CNN further. Moreover, the hysteresis characteristics are introduced for these functions, which make tolerance to a noise robust. It is demonstrated mathematically that under a mild assumption, the stability of the CNN which has an output function with hysteresis characteristics is guaranteed, and the impressive simulation results are also presented. Index Terms--Cellular neural network (CNN), hysteresis characteristics, intensity conversion, piecewise-linear (PWL) function, quantization function.

In this paper, a closed-form expression and a macro model for simulation are proposed for the RLCG transmission line expressed in terms of the telegrapher's equation. First, the hyperbolic functions contained in the admittance matrix of the transmission line are analytically expanded in terms of poles and residues, deriving a close expression of the admittance matrix. Next, from the closed-form expression, rigorous poles of the admittance matrix are obtained. By using the closed-form expression, a macro model of the RLCG transmission line is obtained. The passivity of the macro model, a method for determination of the order, and a simulation method in the time domain are discussed. As a numerical example, a closed-form expression and a traditional discretized model of a transmission line are compared. In this way, the effectiveness of the macro model obtained from the closed-form expression is confirmed. © 2003 Wiley Periodicals, Inc. Electron Comm Jpn Pt 3, 87(4): 1–11, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjc.10155 [ABSTRACT FROM AUTHOR]

In the method based on the discrete Fourier transform of transmission line networks, the number of frequency components to be considered depends on the effective frequency of the network and the amount of time the input power supply is restricted. Hence, if the input power supply lasts a long time, many frequency components are needed and the computational efficiency is degraded, even if the effective frequency of the network to be analyzed is unchanged. This is because the network equation needs to be solved every time in order to obtain the response at each frequency. In this paper, a method is proposed in which the solutions of the network equation are sought as few times as possible and the frequency response is approximate instead. As approximation methods, one based on the third-order spline function and one based on the discrete Fourier transform–inverse transform are used. Through numerical examples, it is shown that the proposed method is superior in terms of computational efficiency to the moment matching method (known as a high-speed simulation method) for a relatively small-scale problem. © 2000 Scripta Technica, Electron Comm Jpn Pt 3, 84(3): 81–90, 2001 [ABSTRACT FROM AUTHOR]