Abstract— A highly miniaturized dual-band patch antenna is proposed for small form factor (SFF) devices. The antenna is designed to cover two wireless local area network (WLAN) bands at 2.4 and 5.2 GHz. The antenna is miniaturized using a shorting post and a novel defected ground structure (DGS). The patch size is 8.8mm by 10 mm which means 74% miniaturization ratio is achieved at 2.4 GHz. The dual-band property is achieved by etching a U-slot in the ground as a part of the proposed DGS. The antenna is fabricated on Rogers RO4350 board and its radiation characteristics are measured. The measured results have good agreement with simulated ones.< final year projects >