Investigation of multiband microstrip bandstop filters with and without SMD capacitors

Abstract

This work presents the design of multiband bandstop filters (BSFs) based on defected ground structure (DGS) technique. The filters are loaded by surface-mount device (SMD) capacitors for dual and triple stopbands operated at 3.69/7.63 GHz and 3.2/5.56/7.28 GHz, respectively. An additional BSF structure without SMD capacitors operated at 3.77/7.16 GHz is as well designed and fabricated. Due to their satisfactory stopband performances, the proposed filters can be useful for various communication systems with dual and triple bands rejection for WiMAX/C bands.