The principles of constructing high-order microstrip filters based on single- and dualresonator highly selective sections are being developed. It is shown that a significant increase
of microstrip structure selectivity with a minimum number of resonators can be achieved by
using the method of "reverting" of the transmission zeros, the effect of combining the main and
parasitic passbands, as well as the galvanic connection of the sections instead of their cascade
connection.
Keywords: Attenuation, Coefficient of squareness, Dielectric substrate, Electrical coupling, Frequency response, Galvanic connection, High-order microstrip filter, Microstrip resonator, Ultra-wideband structure.
