WiMAX bandpass filter using hybrid microstrip Defected-Ground-Structure

A novel and compact WiMAX microstrip bandpass filter is proposed. The filter employs a very wide bandwidth from 2 to 11 GHz under NLOS environment of the IEEE 802.16-2004 standard, and with a 3-dB fractional bandwidth of greater than 138%. The proposed hybrid WiMAX band-pass filter had return loss more than 17 dB in the passband, and also demonstrated a reject band from 12.4 GHz to more than 20 GHz at −20 dB.