This article presents two novel resonators, that is, frequency selecting coupling structure loaded stepped-impedance resonator (FSCSLSIR) and π-section loaded FSCSLSIR. The resonator behaviors and guidelines are given to design FSCSLSIR dual-band bandpass filter (BPF) and π-section loaded FSCSLSIR triband BPF. The proposed dual- and triband BPF have very compact sizes of 0.13 λgd × 0.06 λgd and 0.115 λgt × 0.074 λgt, respectively. Moreover, good return loss, low insertion loss, and high band-to-band isolation can be observed, and the proposed FSCSLSIR dual-band BPF has an ultrawide stopband from 5.79 to 36 GHz. The experimental results are in good agreement with the simulations. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:427–435, 2015.