Design of inverted-F antenna for long-term evolution-based wireless handheld Devices

In this article, a compact triple-band inverted-F antenna for long-term evolution (LTE)-based wireless handheld devices is presented. The proposed antenna comprises three arms, namely the radiating arm, shorting arm, and feeding arm. The structure of the designed antenna looks like an inverted F with folded L-shaped strip antenna. It has three resonant frequencies of 795, 2050, and 3405 MHz with a reflection coefficient of --11.7 dB, --15.1 dB, and --30.5 dB, respectively. The size of the suggested antenna is 10 $\times$ 35 $\times$ 0.8 mm$^3$ and it is built on the FR-4 substrate which is more compact and easy to integrate with the handheld devices such as laptops, tablets, and smart phones. The performances of the proposed antenna are analyzed with the help of computer simulation using Ansys High Frequency Structure Simulation Software Simulator (HFSS). The measured --10 dB impedance bandwidth of the suggested antenna covers 780--820, 2020--2070, and 3230--3490 MHz, which satisfies the LTE 700, LTE 2100, and LTE 3300. The proposed antenna has the acceptable voltage standing wave ratio (VSWR $\leq$ 2), bandwidth, gain, and radiation characteristics across the operating bands and thus proves its suitability for wireless handheld devices.