A new dual-band microstrip bandpass filter using net-type resonators

In this letter, a new dual-band microstrip bandpass filter is developed using net-type resonators. The net-type resonator is designed to simultaneously operate at two closely specified resonant frequencies, f₁ and f ₂, and then applied to construct a dual-band filter based on the filter design concept of adding extra coupled resonators. The dual-band filter with the elliptic function response is designed, implemented and experimentally verified in this letter. The measured results of the developed filter are in a good agreement with the simulated results by full-wave electromagnetic simulator. In addition, the developed filter not only has an excellent mid-band rejection, but also provides a wide stopband suppression.