Hochgenaue Abstandsmessung mit Mikrowellen

Using microwave technology for industrial sensing applications has the advantage of being insensitive to environmental influences. The presented near range radar has an accuracy of 0.1 mm. This high precision was achieved by using dynamic frequency divider chips for direct frequency measurement and a six-port for phase measurement at 35 GHz. A digital signal processor calculates the distance.     

Control system design based on holistic eigenvalue allocation

A trade-off between optimum allocation of the entire set of eigenvalues and the size of controller norm or a general actuator effort is carried out for continuous-time and discrete-time systems. Controllers achieving appropriate results are termed holistic. The design is based on the trace and determinant of the closed-loop state-space matrix. To solve the problem within the scope of actuating effort, the norm of the state controller matrixor the actuator effort transfer matrix are taken into consideration. The method is also extended for designing holistic observers. For preserving stability, a Lyapunov condition is included. An erratum to this article is available at .     

Norm constraint regard for stable H2 controllers

For stable output controllers, the standard H₂ problem is modified by additionally including the H₂ controller norm.      

Konvergenz der Kommunikationsnetze zu Multiservice-Netzen

The rapid progress in the convergence of communication networks (fixed and mobile networks with data networks) to multi service networks has an impact on the principles of the traditional switching technologies. Future requirements will also have to be fulfilled through service-convergence (bundling of individual services to new services) regardless of organizational or technical boundaries. Requirements in the information- and communication-business all the way to technical network aspects are to be faced. Based on developments in microelectronics, two converging evolutions by packet-oriented technologies (within the network and at the edge of the network) are now taking place. Starting with the principles of circuit-switching and packet-switching the change in today’s telecommunications world will be discussed. Apart from that emphasis will be put on the distribution of the switching functions within the network, the change of the network’s topology, as well as the influence on the signalling protocols (extensions and new approaches).     

Koordinatenmesstechnik für biomedizinische Anwendungen

The importance of computer aided measurement techniques as a means of controlling industrial manufacturing and testing technical products with high accuracy is increasing ever more with the general goal of improving the quality of all kinds of products. This development started about twenty years ago and is still improving. There is also rapid development in biomedical technique and this demands the application of modern computerized measurement techniques and measuring devices. Especially computer aided co-ordinate metrology can be applied as a very important and universal tool for solving complex measuring tasks for workpiece metrology, to evaluate the measuring results to give the basis for the improvement and optimization of future work in the biomedical technique.     

Vergleich, Dimensionierung und Realisierung einphasiger Power Factor Correctors minimalen Realisierungsaufwands

In the future laws and restrictions will limit the amplitudes of the low frequency harmonics of mains currents of rectifier systems. While diode bridges are very simple, compact and cheap, their input current shows high low-order harmonics. In the past various rectifier systems have been developed that avoid low-order input current harmonics by means of active current control. The significantly reduced input filter results in a small and compact total rectifier system. In this paper different rectifier systems are discussed and compared. Since industry is interested in simple and cheap solutions the rectifier systems are discussed under these considerations. Besides an introduction of different power circuits and control schemes, the systematic choice of the power semiconductors is presented.     

Messmethoden zur Charakterisierung von Mikrowellenleistungstransistoren

For first try designs of microwave power amplifiers it is necessary to know the entire physical behaviour of the used components with high accuracy. The attention should be directed especially to the center component of these circuits, the power transistor, whose nonlinear characteristics have an essential impact on the behavior of the whole amplifier. This article gives an overview of current methods of measurement for microwave power transistor characterization. Furthermore a measurement system is presented, capable of characterizing microwave power transistors within a frequency range from 30 kHz to 8.7 GHz at bias current up to 7.5 A including self heating effects.