Miniaturized dual-band II-shaped monopole antennas with modified rectangular ground plane

Dual-band antenna covering IEEE 802.11a/b/g bands is presented using a miniaturized II-shaped monopole antennas with modified rectangular strip ground plane for dualband WLAN operation over the frequency band of 2.400-2.484 GHz, 5.150-5.350 GHz and 5.725-5.825GHz. The II-shaped monopole antenna and with modified rectangular ground plane are etched onto a piece of printed circuit board (PCB) with an overall size of 25 mm × 44 mm × 1.6 mm. This antenna can easily be fed by strip line to match impedance using a 50 ohm transmission line with SMA connector. The measured results show that the miniaturized antenna achieves a broad operating bandwidth of 2.26-2.89 GHz and 4.92-5.83 GHz for |S₁₁|<; -10 dB and omnidirectional radiation pattern. The measured gains of the antenna from 2.400 to 2.484 GHz and 5.150 to 5.825 GHz frequencies are 1.3 dBi and 2.5 dBi, respectively.