G.M. Aristarkhov¹, I.N. Kirillov², A.I. Korchagin³, V.V. Kuvshinov4

1,2 Moscow Technical University of Telecommunication and Informatics (Moscow, Russia)

3 Mitishinsky Scientific-Research Institute of Radio Measuring Instruments (Mitishi, Russia)

4 CEO LLC NPP «FLICS» (Moscow, Russia)

In this paper, the authors study the design specifics of compact highly selective microstrip filters based on structures with a significantly limited number of half-wave folded co-directional hairpin resonators. The increased frequency selectivity of these structures achieved due to the formation in them, under certain conditions, a significant number of working attenuation poles at finite frequencies. In this case, the transfer characteristic order of this type of filters is determined in the passband by the number of resonators in the structure, and in the stopband − by the number of the working attenuation poles, which is significantly greater than the number of resonators in the filter. This provides a combination of low passband loss and increased frequency selectivity in the stopband. Presented results of numerical electrodynamic 3D simulation and experiments of three- and four-resonator microstrip filters are in good agreement and confirm the high efficiency of the circuit solutions under consideration. Filters of this type are physically realizable within the standard thin-film and thick-film technologies, and their electrical parameters are stable to the technological spread of the elements' parameters. This type filters combine high compactness, reduced loss level, and increased frequency selectivity, that makes it possible to widely use them in integrated microwave devices for various applications.

Aristarkhov G.M., Kirillov I.N., Korchagin A.I., Kuvshinov V.V. Compact highly selective filters on folded co-directional hairpin resonators. Radiotekhnika. 2021. V. 85. № 4. P. 126−137. DOI: https://doi.org/10.18127/j00338486-202104-14 (In Russian)

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