Triband Inverted-F Antenna With Stacked Branched Monopoles and a Parasitic Strip

This letter proposes a triband antenna design for Wi-Fi (2.4-2.48 and 5.15-5.8 GHz) and WiMAX (3.3-3.7 GHz) applications. In order to accommodate the antenna into the limited space, two L-shaped monopoles are stacked on top of each other. These stacked monopoles are used for the radiation in 2.4- and 3.5-GHz bands. Additionally, one parasitic U-shaped strip is placed alongside the stacked monopoles for the radiation in the 5.5-GHz band. Two on-chip inductors are inserted into the monopoles for impedance matching and further miniaturization. The proposed design can be contained in a volume of 8 × 8 × 1.6 mm³ and built on the printed circuit board. Simulation and measurements are conducted, and both results have proven to be in good agreement.