In this paper, the design of a dual-band bandpass filter (BPF) with narrow- and wide-band performances simultaneously is presented. The proposed filter only uses two stepped-impedance resonators (SIRs) to achieve the narrow- and wide-band performances. Moreover, transmission zeros are created near the passband edges to improve the band selectivity and can be controlled easily by arranging the coupling structures. A filter example is designed and implemented for global system for mobile communications (GSM) at 1.8 GHz and lower passband of the direct sequence ultra-wideband systems (DS-UWB) at 3–5 GHz. The measured results of the fabricated filter confirm the concepts of the proposed design and match the simulated results.
Relation:
Journal of Electromagnetic Waves and Applications, Vol.25, pp.1605-1615 J. of Electromagn. Waves and Appl.
