Abstract:
|
Recent demand for multifunctional wireless devices
has increased the challenge for the antenna designe
rs, who has to
address it by providing small antennas able to oper
ate in
multiple communication standards. This paper propos
es a new
generation of radiating systems capable of providin
g multi-band
operation without the need of including a dedicated
antenna. The
solution is based on the excitation of a structure
already existing
in any wireless handheld device, the ground plane.
Said
excitation is carried out through a pair of booster
s with
dimensions 5 mm x 5 mm x 5 mm, especially designed
to transfer
the maximum power to the efficient ground plane rad
iation
mode. In addition, a radiofrequency system is combi
ned with the
booster-based radiating structure in order to provi
de penta-band
operation. The feasibility of the proposal has been
tested by
electromagnetic simulations as well as by experimen
tal
measurements. Furthermore the human head interactio
n
concerning Specific Absorption Rate (SAR) has been
analyzed
and a proposal for its reduction is presented. As a
result a
promising standard solution for a radiating system
capable to
operate in the main communication standards GSM850,
GSM900, DCS, PCS and UMTS is provided with a volume
reduction factor around 20 compared with current te
chnologies |