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A novel, compact and low profile internal antenna capable of operating in multiple bands is proposed. It consists of a long monopole ring, which is top-loaded by a helical element in order to produce two main resonances of wide bandwidth. Its compact size of length 10 mm, width 28 mm and height of 6 mm and small volume of 1.68 cm³, makes it possible to be used internally, inside the mobile phone. With the help of a small matching circuit a VSWR < 3 is achieved covering the bands of GSM900 (880-960 MHz), DCS (1710-1880 MHz) and PCS (1850-1990 MHz). The efficiency is above 50% in all bands. The Specific Absorption Rate (SAR) is also measured, presented and discussed in this paper.

antenna; mobile phone antenna; monopole antenna; helical antenna; multi-band antenna