G.M. Aristarkhov - Dr. Sc. (Eng.), Professor, Head of Department of Moscow University of Communication and Information. E mail: g.aristarkhov2010@yandex.ru
N.V. Zvezdinov - Post-graduate Student, Moscow University of Communication and Information. E-mail: nikitazvezdinov@mail.ru
V.P. Chernyshev - Ph.D. (Eng.), Head of Department of JSC Vympelcom. E-mail: vpchern@mail.ru

The article examines the structure of compact microstrip filters based on co-directional (collinear) hairpin resonators. Basic element of microstrip filters employing co-directional hairpin resonators is irregular quarter wavelength lattice section of two coupled lines formed by adjacent resonators. The main purpose of this work is to investigate the possibility of a significant increase in the selectivity of the microstrip filter based on co-directional hairpin resonators by organizing additional electromagnetic coupling of a certain type as between adjacent lattice sections as well as nonadjacent resonators.

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