In this letter, a novel monopole antenna for USB dongle applications is proposed. It is composed of a monopole and an inverted U-shaped parasitic radiator. The monopole acts as a feeding structure in the 2.4-GHz band while serving as a main radiator in the 5.5-GHz band. By properly combining the antenna resonance and the ground resonance, the proposed antenna has a wide bandwidth at f ₁ . Also, a wide bandwidth at f ₂ is easily achieved by coupling between the monopole and parasitic radiator. From the measured results, the 10-dB reflection coefficient bandwidth of the proposed antenna covers WiBro (2300-2390 MHz), Bluetooth (2400-2484 MHz), WLAN (2400-2485 and 5150-5850 MHz), WiMAX (2500-2700 MHz), and S-DMB (2605-2655 MHz) bands.