Planar‐circuit bandpass filters consisting of arbitrarily shaped elements

This paper presents an arbitrarily shaped circuit as a planar circuit filter optimized by using a genetic algorithm and develops new, never-before-seen planar circuit elements. A GA optimization algorithm, which can arbitrarily set the input/output line width and shielding box dimensions according to the optimization conditions for the planar circuit filter, and a method for analyzing planar circuit filters of arbitrarily shaped elements by the method of moments are discussed. As a design example, the authors perform optimizations based on the specifications for a conventional bandpass filter; the resulting filters construct a passband without filter synthesis using an equivalent circuit, and have a smaller size and multiple attenuation poles. The effectiveness of the planar circuit filters with arbitrarily shaped elements is examined by fabricating the filter structures obtained by the GA, performing an experiment, and making a comparison with analytical results. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 90(2): 1–8, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20292

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