## Frequency Filtering in Telecommunications

• Piezoelectric filters are used in telecommunication to filter electrical signals. This report deals with the problem of calculating passing and damped frequency intervals for a filter with given geometrical configurations and materials. Only periodic filters, which are widely used in practice, were considered. These filters consist of periodically arranged cells. For a small amount of cells a numerical procedure to visualise the wave propagation in the filter was developed. For a big number of cells another model of the filter was obtained. In this model it is assumed that the filter occupies an infinite domain. This leads to a differential equation, with periodic coefficients, that describes propagation of the wave with a given frequency in the filter. To analyse this equation the Spectral Theory for Periodic Operators had to be employed. Different ways -- analytical and numerical -- to apply the theory were proposed and analysed.

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Author: Ariadna Farres Basiana, Hanna Martinsson, Brage Ofstad Vik, Sergiy Pereverzyev, Martin Purrucker, Klaus Erich Schmitz Abe, David Stiel, Uldis Strautins urn:nbn:de:hbz:386-kluedo-16259 Sabine Zaglmayr Report English 2004 2004 Technische Universität Kaiserslautern ECMI 2005/03/15 SAW filters ; eigenvalue problems ; piezoelectric periodic surface acoustic wave filters ; wave propagation Fachbereich Mathematik 5 Naturwissenschaften und Mathematik / 51 Mathematik / 510 Mathematik Standard gemäß KLUEDO-Leitlinien vor dem 27.05.2011

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