Multiband monopole antenna with complementary split‐ring resonators for WLAN and WiMAX applications

Presented is an electrically small multiband monopole antenna based on complementary split‐ring resonators, which are used to reduce antenna size. The antenna is fed by a three‐stage microstrip line and provides 13, 17 and 16% impedance bandwidth performance covering the 3.5 GHz WiMAX and 2.4/5.2 GHz WLAN bands. Also, the proposed antenna exhibits almost an omnidirectional radiation pattern in the H‐plane and a dipole‐like radiation pattern in the E‐plane. The return loss and radiation pattern measurements of the fabricated antenna are in very good agreement with simulation results.