THE fragile microwave frequencies that will be used by future generations of
cellphones cannot easily pass through house and office walls. So Roke Manor
Research in Hampshire, part of the Siemens group, has filed patents around the
world on a “smart brick” which can make walls transparent to the signals.
Roke says its main priority is developing new 3G devices, but its researchers
were faced with conflicting requirements. Mobile phones are no longer just
phones, they are use-anywhere, do-everything devices
(New Scientist, 21 October 2000, p 29).
But the higher frequencies allocated to 3G, over 2
gigahertz, are significantly…
