Planar asymmetric dual-mode filters based on substrate integrated waveguide (SIW)

Substrate integrated waveguide (SIW) can be used to implement high Q waveguide components with the same process as planar circuits. In this paper an inline and a folded three-pole dual-mode filters with asymmetric transmission response based on SIW are presented. These two filters, consisting of a TE/sub 102/-TE/sub 301/ dual-mode cavity and a TE/sub 101/ mode cavity, are centered at around 9.85 GHz with a transmission zero on the left of the passband and the right of the passband, respectively. A linear microstrip taper was used to implement the transition between microstrip and SIW. The measurement results agree with simulation results.