Abstract
A novel substrate integrated waveguide (SIW) filter with source-load coupling based on low temperature co-fired ceramic (LTCC) technology is proposed. By introducing mixed coupling into input/output SIW in middle layer, the filter not only has good selectivity owing to the controllable transmission zeros, but also has a compact size by the virtue of LTCC structure. Based on the flexible coupling manner in multilayer structure, a demonstration second-order bandpass filter with three transmission zeros has been designed and fabricated. Good agreement between measured and simulated results is observed.