Novel multilayered substrate integrated waveguide narrowband filters for millimeter-wave 3D-MCM applications

Two novel bandpass filters (BPFs) with the same structure but different bandwidth are presented in this paper, they are based on multilayered printed circuit boards. In this work, an H-shape coupling slot is used to realize hybrid coupling, two substrate integrated waveguide (SIW) cavities in different layers are used for resonators, and the coplanar waveguide (CPW) in input and output port is used for feeding line. Due to the size and location of coupling slots changed, the second filter has narrower bandwidth and better suppression in stopband. With the 3D environment, the proposed filters overcome the drawback of large circuit size of traditional waveguide filters, and can be effectively used for 3D Multi Chip Model (3D-MCM) in Ka band. The simulated results show that the 3dB bandwidths are 1.88 GHz (FBW=5.4%) and 0.42 GHz (FBW=1.2%) respectively, and the insertion losses at central frequency are about 1.4 dB and 4.3 dB respectively. The circuit sizes of the two filters excluding feed lines are the same, which are about 0.5λg × 0.5λg, where Ig is the guided wavelength at the central frequency.