Wireless LAN diversity antenna system for PCMCIA card integration

In this paper a new supercompact flat three-dimensional antenna, the bent stacked slot antenna (BSSA) is presented. With its size of 16/spl times/8/spl times/5.2 mm/sup 3/ at 5.2 GHz the BSSA allows integration into an extension of a PCMCIA card which protrudes out of the WLAN terminal, e.g. a laptop. The BSSA as a single radiator has an omnidirectional radiation pattern with its main lobe in the direction of its groundplane. The BSSA was specially designed to achieve a large bandwidth (/spl sim/30%). As an air antenna it has a high efficiency-more than 90%. The large bandwidth of the BSSA guarantees that the antenna is tolerant with respect to manufacturing inaccuracies in a wide range, as well as proper matching and radiation almost independent of the near scattering environment. The BSSA can be very easily constructed from one thin sheet of metal. One application is given for a three branch spatial diversity system for HIPERLAN, which fits into a volume of 54/spl times/32/spl times/5.2 mm/sup 3/, i.e. in an extension of a PCMCIA card.