Dual-band bandpass filter based on CPW series-connected resonators

A new design of a three-pole dual-band bandpass filter using coplanar waveguide (CPW) series-connected resonators and impedance inverters is proposed. The circuit conversions that lead to the lumped element model of the proposed filter are introduced. The resonators of the filter are implemented using special compact series-connected resonators patterned in the centre conductor of a CPW transmission line. The filter operates at the two centre band frequencies 1.8 and 2.4 GHz. Hence, it is considered an excellent candidate for GSM/Wi-Fi applications. Experimental results show very good agreement with simulated results, which validates the proposed filter.