Design of a Small-Sized Filter on Quarter-Wave Hairpin Resonators

The report discusses the results of the design of the original microstrip filter, consisting of several resonators of different electrical lengths with equality of their geometric length. The purpose of the work is to analyze and optimize the filter design. It is shown that the main bandwidth of the filter is formed in the vicinity of the resonant frequency of quarter-wave resonators, since half-wave resonators of the same geometric length have twice the resonant frequency. Simplification of the design of the filter led to a reduction in its dimensions by almost half. When designing the device, the method of filter synthesis was used, which does not impose restrictions on the distance between parts of the resonator that is rolled into a hairpin.