Anritsu S251C - Manual (Page 59)

Two Port Measurements
Introduction
A Tower Mounted Amplifier (TMA) can be used to amplify the received signal. There are
different types of TMA depending on the system requirements. Three commonly used types
are:
q TMA-D
¾A duplex tower mounted amplifier that combines transmit and receive
ports from the radio system and connects to a single antenna. This configuration is
specific to systems that use a single antenna configuration.
q TMA-S
¾A receive-only tower mounted amplifier is installed between the receiving
antenna and the radio to boost weak signals. This configuration is common on sys-
tems that implement separate antennas for transmitting and receiving.
q TMA-DD
¾A dual-duplex tower mounted amplifier used for radios systems with a
single transmission line connection for transmit and receive. These systems are com-
monly called transceivers.
During installation of the TMA, the following tests should be conducted:
q Antenna Subsystem Return Loss Testing to verify antenna performance.
q TMA performance testing to verify the tower mounted amplifier performance.
q Insertion Loss Measurement Test to verify the transmission line performance before
TMA installation and connecting the antenna.
When troubleshooting TMA problems, the following test should be conducted:
q Insertion Loss Measurement Test to verify the transmission line performance after
TMA insertion.
q DTF-Return Loss with the TMA removed from the configuration.
Chapter 4 Measurements
4-12
ANT TX RX
TMA-D
S251C
RF OUT
S251C
RF IN
(Bias Tee)
TMA-S
ANT RX
TMA-DD
ANT RX/TX
S251C
RF OUT
S251C
RF IN
S251C
RF OUT
S251C
RF IN
(Bias Tee) (Bias Tee)
Figure 4-7. Types of Tower Mounted Amplifiers