A wideband microstrip patch antenna using a dual U-slot with low profile has been proposed, and was simulated by means of CST software. The U-slot technique can be used to design and fabricate multiple-band rectangular patch antennas. Through the precise positioning of the slot in the patch, triple-band resonant modes are achievable. The antenna’s performance is enhanced by adding a gap in the ground plane. The VSWR of the proposed antenna at each operating frequency is equal to 1, indicating that the antenna exhibits good impedance matching at those frequencies. The simulated results showed that the antenna would be effective in WLAN, LTE cellular, and WiMAX applications.