Abstract
A rotated A-shaped antenna working at around 2.45 GHz is presented for a wireless sensor network application. The studied antenna is comprised of an A-shaped patch and a small defected ground plane and is printed on both sides of the FR4 substrate material. One I-shaped parasitic slit is added to the tip of a rotated A-shaped patch to form a matching circuit that helps the studied antenna to excite at around 2.45 GHz. The experimental result shows that for S-11 <= -10dB, the presented antenna achieved an impedance band ranging from 2.3 to 2.57 (270 MHz) GHz. The studied antenna also attained appreciable gain, efficiency and exhibits a stable omnidirectional radiation pattern over the working band, which makes it suitable for sensor nodes.