This document presents a compact multiband planar inverted-F antenna (PIFA) with a slotted ground plane for use in personal communication devices. The proposed antenna is 25 x 15 x 3.8 mm in size and uses two open-ended slots in the ground plane to reduce its volume while maintaining performance. Simulation results show the antenna resonates at 1.9 GHz, 2.4 GHz and 5.4 GHz, covering frequency bands including GPS, Bluetooth, LTE, and WLAN. Introducing slots in the ground plane allows the antenna to be more compact while still achieving good impedance matching and gain across multiple bands required for modern wireless devices.