The document presents a design for a multiband planar inverted-f antenna (PIFA) with a slotted ground plane, aiming to reduce the thickness of mobile communication devices while maintaining high performance across multiple communication standards such as GPS, GLONASS, and LTE. The proposed antenna, measuring 25 x 15 x 3.8 mm3, utilizes a ground plane as a radiator to improve operational bandwidth and achieve compactness. Simulation results confirm that the antenna meets the requirements for advanced wireless devices, covering a range of frequencies, including major cellular and non-cellular bands.