Compact Planar Dual-band Monopole Antenna with Bent U-shaped Slot for WLAN/WiMAX Applications

A planar compact dual-band monopole antenna for WLAN and WiMAX applications is proposed in this paper. This design is constructed with a bent U-shaped slot, which occupies a small area of 8(L) × 8(W) mm^2 to be easily embedded inside a portable device as an internal antenna. By properly forming the U-shaped slot on the radiator, two frequency bands covering 2.37-2.53 GHz and 4.36-6.52 GHz can be achieved with our antenna. The antenna's resonance can be also optimized by tuning the slot. Simulated and measured results are performed and discussed. Experiments indicate that the antenna can radiate with nearly omnidirectional coverage and stable gain variation for practical application. With a compact size and dual-band operation, the proposed monopole antenna is well suitable for application in WLAN/WiMAX systems.