Coplanar waveguide‐serially‐connected coplanar strip dual stub structure for wideband bandpass filters.

In this paper, a kind of coplanar waveguide (CPW)‐fed series stub structure is proposed and its application in wideband bandpass filters (BPFs) is developed based on the coplanar strip (CPS) dual stubs. Compared with its conventional CPS dual‐series‐stub counterparts, the proposed one excited by even‐mode CPW lines possesses enhanced immunity against unexpected resonance of the CPS‐based series stubs. By virtue of this attractive performance, desired resonance can be well realized with predicted in‐band characteristics. Subsequently, the application in its constituted wideband BPFs is investigated with synthesis design method. In final, one third‐order and one fifth‐order BPFs are designed, fabricated, and measured to verify the proposed structure. Measured results are found in reasonably good agreement with the synthesized and the simulated ones. [ABSTRACT FROM AUTHOR]