Application 2:
Measurements using a coupling device
When using a bidirectional coupler you can take the same mea-
surements as on the attenuated output. You can also test the
match between antenna and radio by measuring the reflection
value. A high reflection value indicates a mismatch. A mismatch
may reduce the coverage of the base station and is often
caused by defective antennas.
Many base stations already include a fixed bidirectional coupler;
for testing base stations without this feature, bidirectional coup-
lers are available from Acterna (Dual-Band Coupler, order
code AC-016953). This device if of high accuracy and superior
to many couplers built into base stations.
• Connect one end of the blue cable to the Main connector of
the BAT and the other end to the forward port of the bidirec-
tional coupler (normally the coupler port which is closer to
the radio).
• Connect one end of the yellow cable to the Reflection con-
nector of the BAT and the other end to the reflected port of
the bidirectional coupler (normally the coupler port closer to
the antenna).
Warning:
Always use the coupled port
of a coupling device. Never connect the
BAT directly to the high-power output of
the radio or to the feedthrough connec-
tor of the coupler. Direct connection can
be hazardous and will destroy your test
instrument.
