This paper presents a novel coplanar waveguide (CPW) dual passband filter using the split-modes of the loaded stub square loop resonators. With the CPW feeding line, two microstrip stub resonators built on the rear sides are used to suppress the first even resonance. The modes splitting characteristics of the proposed structure are analyzed. A dual passband filter covering center frequencies of 4.8 GHz and 6 GHz is fabricated to verify the validity of the methodology. Good agreement between simulated and measured results is demonstrated.
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