Specifications

ETSI
Final draft ETSI EN 3
00 328 V1.8.1 (2012
-
04)
66
Figure B.2: A typical Semi Anechoic Room
In this facility the ground plane creates a wanted reflection path, such that the signal received by the receiving antenna
is the sum of the signals received from the direct and reflected transmission paths. The phasing of these two signals
creates a unique received level for each height of the transmitting antenna (or UUT) and the receiving antenna above the
ground plane.
The antenna mast provides a variable height facility (from 1 m to 4 m) so that the position of the measurement antenna
can be optimized for maximum coupled signal between antennas or between a UUT and the measurement antenna.
A turntable is capable of rotation through 360° in the horizontal plane and it is used to support the test sample (UUT) at a
specified height, usually 1,5 m above the ground plane.
The measurement distance and minimum chamber dimensions can be found in clause B.1.4. The distance used in actual
measurements shall be recorded with the test results.
Further information on Semi Anechoic Rooms can be found in TR 102 273-3 [i.13].
B.1.3 Fully Anechoic Room (FAR)
A Fully Anechoic Room is an enclosure, usually shielded, whose internal walls, floor and ceiling are covered with radio
absorbing material. The chamber usually contains an antenna support at one end and a turntable at the other end. A
typical Fully Anechoic Room is shown in figure B.3.