Stepped and tapered-stepped constructions of a monopole antenna for handset mobile telephones

In this paper novel different constructions of a monopole antenna including stepped, up-tapered stepped, up-down-tapered stepped and down-up-tapered stepped constructions were suggested. It was shown through this work that the centre frequency of the adopted constructions can be reduced by more than 30% and the bandwidth can be increased to about 150%-200% with a return loss L/sub retn/ /spl ges/ 10 dB, as compared with the quarter-wave monopole antenna at the same physical length. Optimized models for the suggested antenna constructions were achieved with the assistance of a finite element-based solver and designed practically with a centre frequency around 900 MHz to cover the E-GSM-900 (880 MHz - 960 MHz) frequency.