Dual-band planar inverted F antenna for GSM/DCS mobile phones

A compact dual-band planar inverted F antenna suitable for the application as a global system for mobile communication/digital communication system (GSM/DCS) dual-band mobile phone internal antenna is proposed and implemented. The proposed antenna has three resonant elements, two meandered metallic strips of slightly different lengths and one nearly-rectangular patch, which are printed on a supporting FR4 substrate and arranged in a compact configuration. These three resonant elements share a common shorting pin, and for the GSM (890-960 MHz) operation, the proposed antenna is operated with the two meandered strips both resonated as a quarter-wavelength structure, leading to a wide bandwidth formed by two resonant modes. For the upper band of the proposed antenna, three resonant modes are generated, two from the second higher-order modes of the two meandered strips and one from the nearly-rectangular patch, leading to a wide bandwidth covering the DCS band (1710-1880 MHz). The antenna design and experimental results are presented.

I. Introduction

To provide dual-band internal antennas for mobile phones of modern communications systems such as the global system for mobile communication (GSM) [890–960 MHz] and digital communication system (DCS) [1710–1880 MHz], a variety of antenna designs based on the planar inverted F antenna (PIFA) have been reported [1]–[8]. GSM and DCS dual-band operations of these PIFA designs are obtained by inserting an L-shaped or a folded slit [1] or by embedding a U-shaped slot [2] in the antenna's radiating patch or by using two folded radiating patches of different dimensions [3]–[6] or by meandering the radiating patch using several narrow linear slits [7], [8].