In this paper, a small internal antenna for a mobile handset is presented using multiband, wideband, and high-isolation multiple-input multiple-output techniques. The proposed antenna consists of three Planar Inverted-F Antennas (PIFAs) that operate in the Global System for Mobile communication (GSM900), the Digital Communication System (DCS), the Personal Communication System (PCS), the Universal Mobile Telecommunication System (UMTS), and Wireless Local Area Network (WLAN) bands with a physical size of 40 mm ? 10 mm ? 10 mm. A resonator attached to the folded PIFA creates dual resonances, achieving a wide bandwidth of approximately 460 MHz, covering the DCS, PCS, and UMTS bands; a meander shorting line is used to improve impedance matching.