Miniature Dual-Band Microstrip Antenna for Wireless Local Area Network Applications

A compact microstrip-fed dual-band antenna based on multi-branch structure is proposed for wireless local area network (WLAN) applications. The radiating patch of the antenna is a multi-branch patch with an asymmetric structure, where the shorter path realizes the high-band radiation at 5.0 GHz and the longer path realizes the low-band radiation at 2.4 GHz. An extra resonant point is generated near 2.4 GHz by loading the T-shaped strip at the top of the antenna, which expands the bandwidth of the lower band. The simulation results show that the antenna complies with the IEEE 802.11 series WLAN standards, meets the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.4 / 5 \text{GHz}$</tex> dual-band operation requirements, has a wide operating bandwidth as well as good impedance matching characteristics, and can realize approximate omnidirectional radiation in the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{H}$</tex> plane direction.