Dual broadband antenna with compact double ring radiators for IEEE 802.11 ac/b/g/n WLAN communication applications

Abstract

In this paper, a dual broadband antenna is proposed for WLAN communication modules supported by the IEEE 802.11 ac/b/g/n standard. The antenna design is based on two interspaced electrically small split-ring resonators, each of which is directly fed through the stepped impedance microstrip line with an optimized electromagnetic coupling distance in between. The proposed dual band antenna operates in the lower frequency band from 2.3 GHz up to 3 GHz with 2.65 GHz center frequency (26.4 % bandwidth) and in the higher frequency band from 4.7 GHz up to 6 GHz with 5.35 GHz center frequency (24.3% bandwidth). The radiating section of the antenna is λ0 /5.8 × λ0 /10.2 at 2.4 GHz in the lower WLAN frequency band. The return loss is numerically calculated and experimentally measured with the result of good agreement between them. The antenna gain values are 4.77 dBi, 2.9 dBi, and 2.45 dBi at 2.45 GHz, 5.2 GHz, and 5.8 GHz, respectively, with omnidirectional radiation patterns at the horizontal plane. The omnidirectional radiation patterns at both frequency bands allow the proposed WLAN antenna to be utilized for modern mobile broadband wireless network applications.