Dual Band Microstrip Bandpass Filter for GSM

Abstract

A new configuration of Dual Band Microstrip Bandpass Filter was proposed and developed ona basis of the Stepped Impedance Resonators( SIR ) and the Parallel Coupled Microstrip Line( PCML). Spiral compact was used as the Stepped Impedance Resonators for tuning dual bandresonators, and Hairpin comb structures was used as the coupling and matching network at input andoutput. Both were proposed to achieve dual band characteristics. The filter was designed to have themain center frequency at 900 MHz and second frequency at 1,800 MHz Measured characteristics ofthe filter indicated a reasonable agreement with simulated responses