A broadband substrate integrated waveguide (SIW) filter

Abstract

Broadband filters are constantly requirement in wideband transceivers which often cover a whole microwave band. Traditionally, microwave filters have been implemented as passive networks of waveguide, coplanar waveguide, microstrip, etc. More recently, microwave filters have also been realized in substrate integrated waveguide (SIW) technology. Compared to microstrip circuits, the SIW components have many advantages, such as high Q-factor and low radiation losses. Additionally, they are smaller than the corresponding conventional rectangular waveguide components. An eleven-stage broadband SIW filter has been designed, fabricated and measured. The measured results show that the SIW filter can be operated from 9.25 GHz to 11.25 GHz with good selectivity performance. The filter has a small size, low weight, and can be integrated with other SIW components without any transitions. It is suitable for the design of microwave and millimeter wave integrated circuits.