Microstrip dual-band band pass filter using hairpin resonator and microstrip tapped feed line

A new miniaturized microstrip filter using 3 stepped impedance resonators and micro strip tapped feed line is designed for dual band applications at the frequencies 2.5 and 6 GHz . The microstrip line is loaded with stepped impedance hairpin resonators through coupling lines. To construct band pass filter parallel and series resonance characteristics of stepped impedance hairpin resonator is utilized. The stepped impedance resonator acts as a loading impedance and creates two pass bands. Three attenuation poles are created at 0.5, 3.8 and 6.8 GHz respectively. The filter is simulated using ADS 2009 software. The designed dual band bandpass filter achieves the insertion loss less than 1dB and the return loss is -17 dB and -25 dB at 2.5 and 6 GHz respectively .This proposed filter structure is suitable for satellite, mobile and other wireless communication systems.