In this paper, focus is on a comparative study of two topologies of bandpass filter based on a Substrate Integrated Waveguide (SIW) approach. The filters under study must meet electrical specifications in C-band for a space application. One of them is a 6th order inductive-post SIW filter that presents transmission zeros thanks to cross-coupling. The other one is a 4th order filter built from the association of Hybrid Planar Waveguide Resonators (HPWRs) and Dual Behavior Resonators (DBRs) which presents intrinsically transmission zeros. As filters are aimed to be used in a space environment, additional considerations such as sensitivity to the packaging, size and thermal behavior have to be taken into account. The results from experiments are compared to the simulated data.