Wideband slotted planar inverted-F antenna for millimeter-wave 5G mobile devices

A compact slotted planar inverted-F antenna (PIFA) with a superstrate is presented in this paper. The proposed antenna covers 28 GHz millimeter wave frequency bands and can be useful for future 5G hand held devices. The antenna has been designed to be integrated to a mobile phone substrate of dimensions 110 mm × 60 mm, while reserving 70 mm × 35 mm area for a battery, and occupies a small volume of 4 mm × 4 mm × 1.34 mm. It has a wide operating bandwidth (|S11| <; - 10dB) of 3.18 GHz (27.57-30.75 GHz) and a peak gain of 8.8 dBi with a gain variation of less than 0.83 dB within the operating bandwidth. The proposed antenna has stable broadside radiation in yz and xz planes with low side lobe levels. It features wide half power beamwidths of 65.90 in the xz plane and 61.10 in the yz plane at 28 GHz. Radiation efficiency and total efficiency of the antenna vary between 97.9%-98.8% and 69.3%-97.3%, respectively.