A commercial perspective on the development and integration of an 802.11a/b/g hiperlan/WLAN antenna into laptop computers

Commercial antenna design for wireless applications involves a significant number of tradeoffs with other competing engineering requirements. The design of an 802.11 a/b/g HiperLan/WLAN antenna into a laptop computer is used to illustrate one path taken to produce a commercially successful dual-band antenna design. The candidate design chosen was a stacked dual-slot configuration, driven with a microstrip line across both slots and shorted at appropriate edges. Coaxial cable was connected to the center of the antenna. The upper slot was shown to have a second fundamental resonance, which precluded a good match at 4.9 GHz with the high-frequency slot. This slot was truncated at its center to eliminate the undesired resonance and to allow the lowest resonance to remain intact, which, in turn, allowed for a good match at 4.9 GHz. The high-frequency slot was then optimized to create a fundamental and a second "fictitious" resonance, which allowed one to create a large impedance bandwidth, as required. The measured impedance, isolation, and gain results for an antenna integrated into a laptop are presented