7 0 0 M H Z B I D I R E C T I O N A L A M P L I F I E R T E C H N I C A L M A N U A L
4
18
Alarm (Led Indicator)
AGC Alarm, S/D Alarm
Alarm: High, Normal Low
19
Voltage(Current)
+28V(3A)/+6V(3A)
20
In/Out Connector
N (F)
21
Size (in)
10H x 16W x 8.5D
22
Operating Temp./Humi.
-10 ~ +50
℃
/95%
Block Diagram Details
-
The 700 MHz Amplifier module contains a (Low Noise Amplifier) LNA designed to detected very week
signal. This stage is bypassed if the signal level at the input is higher than -20dBm
-
The LNA is followed by an Automatic Gain Control (AGC). The AGC circuit measures composite
power level at the VGA input and adjusts automatically the gain, in order to maintain constant the signal
level at the VGA output delivered to the Power Amplifier (PA). Channel filters are inserted, in order to
reject adjacent channel signals and to improve the main signal quality.
-
The PA provides good performance for both linearity and efficiency. This amplifier is heat sink mounted
and produces a high compression point and 3
rd
order Intercept point.
-
The unit can operate with AC or DC supplies. The main AC input accepts 50/60 Hz with a 115 to 220
V AC power source; then the Power Supply Unit (PSU) converts AC to DC voltages to supply DC
power to the Amplifiers and the Monitoring and controle units. The unit can be fed directly with the
DC power, by selecting the DC option on the AC/DC switch and conn24-27 V to the DC input
connector. The operator must ensure that his external DC power supplies are compliant with FCC limits
on the radiated and conducted emission.
-
The unit does not have built-in UPS/Battery system. In case of need for inconsistency in the AC line
power, surge protection, short Black outs, crossover time from line AC to generator power, circuit
breaker for short circuit and over load protection, etc., an external UPS/Battery system is recommended.
-
The unit has two duplexers; one at BTS port allowing the use for only one donor antenna for both UL
and DL. The second duplexer is mounted at the Service DAS antennas port. These duplexers provide at
least 100 dB isolation at each end between the two path..
-
A set of manual gain control (MGC), ranging from 0 to 30 dB in 1 dB steps are also added in the chain
for additional attenuation if needed.
