Electromagnetic interference in substrate-integrated waveguides circuit and its suppression technique

As was well known, the substrate-integrated waveguide can be easily implemented and integrated with active and passive devices using the printed circuit process. Thus, the integration circuit and system based on the substrate-integrated waveguide technique becomes achievable. However, in the integrated circuit environment, the close proximity between adjacent substrate-integrated waveguides may cause the electromagnetic coupling, and thus the electromagnetic interference problem arises accordingly. In this research, we demonstrate the electromagnetic coupling between two parallel substrate-integrated waveguide. Moreover, the theory of Fabry-Perot resonator was employed to explain the resonance coupling between the substrate-integrated waveguides. On the other hand, a new substrate-integrated waveguide equipped with moats was utilized to examine the capability of cross-talk suppression. Interestingly, we find that in comparison with the conventionally used substrate-integrated waveguide the new one can effectively suppress the electromagnetic wave coupling. Therefore, the signal integrity can be further improved in a microwave or millimeter-wave circuit or system implemented using the substrate-integrated waveguide technique.