User Manual

20
Figure 9: Power Amplifier – Front and Rear
Diplexer
The Diplexer separates the TX/RX signal being transmitted to/from the antenna. The
Diplexer supports a very high TX to RX signal separation.
LNA Module
The LNA module receives the upstream received signal from the Diplexer, amplifies it,
and delivers it to the Downconverter. The LNA module includes two Low Noise
Amplifiers in series. A narrow band BPF (band pass filter) is placed between the
amplifiers to improve receive signal filtering. The LNA module has a fixed gain.
Downconverter
The V3300-A band A  ownconverter is preset to receive a signal at 787.5 MHz, and to
convert it to a signal at 44 MHz. Its output signal is spectrum inverted and the unit has a
fix gain of 18 dB. The unit is powered by 6.5V 900 mA supply received from an external
wall mount power supply.