Filter structures based on substrate-integrated waveguide (SIW) technology have been widely studied. SIW filters using complementary split-ring resonators (CSRR) allow to achieve compact size and low loss by operating below the cutoff frequency of SIW transmission lines. This paper presents a study of SIW-based bandpass filters operating in the Ku band, with different configurations of CSRR resonators. The slotted conversion structure is used to further reduce the filter size. Structure 1 and structure 2 in the paper have compact dimensions of 25.7 x 7.2 mm ²  and 12.3 x 7.5 mm ² respectively . The designs also optimize the quality factor of the CSRR resonator to achieve low loss. The designed filters achieve insertion loss less than -1 dB, return loss less than -16 dB in the passband, which are better or equivalent to published results at the same frequency band. The filters are designed and can be targeted for Ku-band satellite communications applications.

*This research was supported in part by VIET ELECTRONIC TECHNOLOGY SOLUTIONS CO., LTD.