A wideband built-in antenna with a new crossed C-shaped coupling feed structure for wireless terminals is presented. With the proposed design scheme, a 10-band built-in antenna that covers LTE700/GSM850/GSM900/DCS1800/PCS1900/WCDMA/WiBro2350/Bluetooth/WiMAX2500/LTE2600 is experimentally tested. The antenna could be available for future 4G service and for current 2G/3G services. This novel 10-band built-in handset antenna is developed within the limits of a 50 x 14 x 16 mm(3) volume for recent smart phones or personal digital assistant (PDA) applications, thereby achieving good agreement between measurement and simulation.