English to Russian Tech/Engineering Electronics / Elect Eng technology(adaptive antenna aray)

Aiming the Beam
RADIO BEAMS ARE OF LITTLE USE, however, if they cannot
be pointed at their intended recipients. The most obvious
solution is to physically turn the antenna array, but this method
is very awkward and expensive. It is much easier to steer the
radio beams electronically. Using one technique, called beam
switching, antenna arrays create a group of overlapping radio
beams that together cover the surrounding area [see top illustration
on page 52]. When a cell-phone user makes a call, the
radio receiver determines which beam is providing the strongest
signal from the user. The array transmitter then “talks back”
using the same beam from which the signal was received. If the
user walks out of the original beam into an adjacent one, the
radio’s control system switches to the new beam, employing it
for both reception and transmission.