Dual-band bandpass filter based on two U-shaped defected microstrip structure

This paper presents design of dual-band bandpass filter by integrating conventional quarter-wavelength short circuit stubs with U-shaped defected microstrip structure notch filter. Based on the parametric analysis, it is found that high attenuation level can be achieved using two separated specific distance. The designed simulated advanced system and fabricated based Roger 4350B. simulation results are in good agreement measured results. covered pass bands centered at 2.51 GHz 3.59 3-dB fractional bandwidth 15.94% 15.86%, respectively, return losses better than 15 dB, insertion 1 dB. device used for wireless communication applications such as WLAN WiMAX.