Compact Dual-Band Suspended Microstrip Slot Antenna with an Antipodal Parasitic Element for WLAN Applications

In this paper, a dual-band microstrip slot antenna over a suspended substrate with an antipodal parasitic element is proposed for wireless local area network systems operating at 2.4, 5.2, and 5.8 GHz. The antenna is composed of multi layers of flame retardant-4 (FR4) and air/foam substrates. The foam/air substrate is included a coaxial single-feed pin and the FR4 substrate is comprised of a modified T-shaped patch and an antipodal modified U-shaped parasitic element with a modified slot around it. The slot antenna configuration improves the compactness, the impedance bandwidth, and the radiation pattern. The realized antenna is proportionately small in size (17 x 20 mm(2)) and experimental result shows that the antenna covers 2.39-2.5 and 5.1-6.05 GHz with the 10-dB return loss bandwidth. Furthermore, the antenna has good radiation patterns in both x-z and y-z planes over the desired frequency ranges.