Resonator-Loaded Dual-Band Monopole for Universal WLAN

This letter presents a novel monopole antenna design for efficient dual-band operation over the entire international wireless local area network (WLAN) frequency bands of 2.4-2.5 GHz (802.11b/g) and 4.9-5.875 GHz (802.11a/h/j). The design is based on the principle of out-of-band loading using a magnetic resonator whose natural frequency is chosen to lie between the lower and upper WLAN bands. The position of the resonator and the frequency of its natural resonance are chosen to produce more than 1 GHz wideband match in the 5 GHz band. The length of the monopole combined with the out-of-band resonator inductance determines the match in the 2.45 GHz band.