A dual-frequency strip-sleeve monopole antenna for a laptop computer

In this paper a dual-frequency strip-sleeve monopole antenna is described for use on a laptop computer. While a conventional monopole operates at only a single frequency band, the new antenna can operate in the 0.824-0.894 GHz and the 1.85-1.99 GHz frequency bands. The operation of the new antenna in two frequency bands is achieved by use of the two parasitic sleeves. This design is based on the principles described by M. Ali et al. (see Journal Electromagnetic Waves Applications, vol.10, no.9, p.1223-36, 1996) The laptop models are highly simplified and each of them consists of two metal boxes: a keyboard and a screen at an angle /spl alpha/. The new antenna is analyzed using the finite-difference time-domain (FDTD) method.