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In large aircrafts the cabling is very complex and often causes reliability problems. This is specially true for modern In-flight Entertainment (IFE) systems, where every passenger can select a preferred movie, play computer games or be able to communicate with other travellers. Due to EMC problems, wireless communication systems (WiFi etc.) didn't succeed in solving these problems. In this paper an innovative communication system is proposed which perfectly supplements an aircraft IFE system. The key innovation of this system is to use structures that are essential parts of the airframe for data transfer, such as seat rails. Those rails consist of rectangular shapes and could easily be modified to fulfill the function of waveguides for microwaves. A waveguide as part of the seat rail would provide enormous benefits for aircrafts, such as a large bandwidth and consequently high data rates, no problems with EMC, unlimited flexibility of seat configuration, mechanical robustness with associated increase of reliability and a few additional advantages related to aircrafts such as reduction of weight and costs.
The advantages of the coupled-mode (COM) formalism and the transmission-matrix approach are combined in order to create exact and computationally efficient analysis and synthesis tools for the design of coupled surface acoustic wave resonator filters. The models for the filter components, in particular gratings, interdigital transducers (IDTs) and multistrip couplers (MSCs), are based on the COM approach that delivers closed-form expressions. To determine the pertinent COM parameters, the COM differential equations are solved and the solution is compared with analytically derived expressions from the transmission-matrix approach and the Green's function method. The most important second-order effects, such as energy storage, propagation loss, and mechanical and electrical loading, are fully taken into account. As an example, a two-pole, acoustically coupled resonator filter at 914.5 MHz on AT quartz is investigated. Excellent agreement between theory and measurement is found.
Der Entwurf von Strukturen zum reflexionsarmen Einbetten von Halbleiterbauteilen in Mikrostreifenleitungsschaltungen gestaltet sich mit steigender Frequenz kritischer. Deshalb wird ein Verfahren vorgestellt, das es ermöglicht, das Streuverhalten solcher Strukturen unter Anwendung der dreidimensionalen Finite-Differenzen-Methode auf die Maxwellschen Gleichungen numerisch zu berechnen. Hierauf aufbauend wurde das Programmpaket F3D entwickelt. Das Streuverhalten einer Verbindung zweier GaAs-Chips durch eine dielektrische Wand wird in Abhängigkeit von Geometrieparametern diskutiert. Außerdem werden Ersatzschaltbilder unterschiedlicher Komplexität für CAD-Anwendungen vorgestellt. Diese ermöglichen zudem eine rechenzeiteffektive Optimierung dieser Struktur, die somit Filteraufgaben übernehmen kann. Dies wird am Beispiel eines Tiefpasses gezeigt.
It is demonstrated that microwave structures incorporating dielectric resonators (DR) are accurately characterised by means of a 3-dimensional finite-difference CAD package. All major assumptions made so far have been dropped, offering the possibility of a rigorous analysis of the embedding of dielectric resonators into microwave structures. In particular, a finite thickness for the microstrip conductor has been taken into account. The coupling of the DR to a microstrip placed in a metallic housing has been theoretically and experimentally investigated. Theoretical and experimental results are in good agreement and give new insight into DR coupling to microstrip circuits.
The advantages of the coupling-of-modes (COM) formalism and the transmission-matrix approach are combined to create exact and computationally efficient analysis and synthesis CAD tools for the design of SAW-resonator filters. The models for the filter components, especially gratings, interdigital transducers (IDTs). and multistrip couplers (MSCs), are based on the COM approach, which delivers closed-form expressions. In order to determine the relevant COM parameters, the integrated COM differential equations are compared with analytically derived expressions from the transmission-matrix approach. The most important second-order effects such as energy storage, propagation loss and mechanical and electrical loading are fully taken into account. As an example, the authors investigate a two-pole, acoustically coupled resonator filter at 914.5 MHz on AT quartz. Excellent agreement between theory and measurement is found.
The embedding of microwave devices is treated by applying the finite-difference method to three-dimensional shielded structures. A program package was developed to evaluate electromagnetic fields inside arbitrary transmission-line connecting structures and to compute the scattering matrix. The air bridge, the transition through a wall, and the bond wire are examined as interconnecting structures. Detailed results are given and discussed regarding the fundamental behavior of embedding.