A NOVEL DUAL MODE SUBSTRATE INTEGRATED WAVEGUIDE FILTER WITH MIXED SOURCE-LOAD COUPLING (MSLC)

A novel single-cavity dual mode substrate integrated waveguide (SIW) filter with mixed source-load coupling (MSLC) is presented. By using an interdigital slot-line (ISL) to introduce mixed coupling between source and load, the proposed filter with only one cavity could have three transmission zeros which can be controlled flexibly. Under the circumstances, the filter exhibits better frequency selectivity in comparison with conventional dual mode SIW filters. An experimental filter with a center frequency of 10 GHz and a 3 dB fractional bandwidth of 6.0% is designed, fabricated, and measured to validate the proposed structure. Measured results are provided to show good performance and in agreement with the simulated ones.