Abstract: A compact internal antenna is proposed for GSM/GPS/DCS/PCS/UMTS/Bluetooth/WLAN/WiFi/WiMAX applications. The proposed antenna is comprised of a loop antenna and a monopole antenna. The antenna system shows wide multi-operation band as well as good radiation patterns and small volume. The antenna can be printed on the system circuit board of the mobile phone and short-circuited to the system ground plane to form a loop-type structure. A comparison with that of the existing antennas showed that wide impedance bandwidth of the proposed structure can be achieved without increasing the implementation complexity.