June 1998, Volume 7, Number 2
M. Dolezal, Z. Raida
Quasi-Static Analysis of Planar Transmission Lines: Conformal Mapping Versus Finite Elements
The presented submission describes an analysis of a classical open microstrip line, of an open microstrip line on a trapezoidal substrate and on a substrate with a limited width and of a microstrip line with a PEC shielding walls on both sides. The analysis is performed using the conformal mapping method and the finite-element one. For all the above described structures, the characteristic impedance is computed by both the methods and obtained results are in detail discussed. Both the methods are compared with respect to their generality, to their CPU time requirements, and to the programming effort required for their implementation.
Z. Tobes, Z. Raida
Analysis of Recurrent Analog Neural Networks
In this paper, an original rigorous analysis of recurrent analog neural networks, which are built from opamp neurons, is presented. The analysis, which comes from the approximate model of the operational amplifier, reveals causes of possible non-stable states and enables to determine convergence properties of the network. Results of the analysis are discussed in order to enable development of original robust and fast analog networks. In the analysis, the special attention is turned to the examination of the influence of real circuit elements and of the statistical parameters of processed signals to the parameters of the network.
D. Kocur, R. Stanko
Polyspectral Analysis of Signals: An Introduction
In this paper, basic terms of the higher order spectrum theory as moments and cumulants of random variables and stationary random processes as well as cumulant and moment spectra are introduced. A part of this paper is devoted to bispectrum estimators. The objective of this paper is also description of bispectrum application for quadratic phase coupling detection.
A. Cizmar, L. Dobos, R. Palitefka
The Wireless ATM Architecture
An overview of the proposed wireless ATM structure is provided. Wireless communication have been developed to a level where offered services can now be extended beyond voice and data. There are already wireless LANs, cordless systems offering data services and mobile data. Wireless LAN systems are basically planned for local, on-promises and in-house networking providing short distance radio or infrared links between computer system. The main challenge of wireless ATM is to harmonise the development of broadband wireless system with service B -ISDN/ATM and ATM LANs, and offer multimedia multiservice features for the support of time-sensitive voice communication, video, desktop multimedia applications, and LAN data traffic for the wireless user.
Kvasiresonant DC-DC Converter with Switching at Zero Current - Part 2
A kvasiresonant DC - DC converter and its control circuits were proposed in the part 1 of the article. The relations useful for design of the converter will be deduced in this part 2. Relations and their numbers of the part 1 will be accepted.