LGC-340/345W
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LGIC
LG Information & Communications, Ltd.
being compared to RF output.
Amplifier part is consisted on RF AMP that has linear Gian control on 26dB, is controlled by TX_AGC_ADJ
from MSM.
Between Upconverter and Drive Amp , there is a band pass filter(F3).
1.3.3 Transmit End Bandpass Filter
Transmit signals that have been converted from IF signals into RF signals after passing through the upconverter
are inputted into the Power Amp, after passing once again through RF BPF in order to filter out noise signals
amplified.
This is carried out in order to create power level inputted to the Power AMP via RF BPF . IL of two RF BPFs is
3.5dB (Max) as a maximum, whereas the ripple in the passing band is 2dB(Max). The degree of the suppression
of transmit signals on receive band is at least 25dB or greater. The maximum power that can be inputted is about
10dBm.
1.3.6 Power Amplifier and Isolator
The power amplifier(P1) that can be used in the CDMA and FM mode has linear amplification capability,
whereas in the FM mode, it has a high efficiency.
For higher efficiency, it is made up of one MMIC (Monolithic Microwave Integrated Circuit) for which RF input
terminal and internal interface circuit are integrated onto one IC after going through the AlGaAs/GaAs HBT
(heterojunction bipolar transistor) process.
The module of power amplifier is made up of an output end interface circuit including this MMIC.
The maximum power that can be inputted through the input terminal is +7dBm and conversion gain is about
30dB.
RF transmit signals that have been amplified through the power amplifier are sent to the duplexer via
isolator(ISO1) and then, sent out to the cell site through the antenna in order to prevent any damages on circuits,
that may be generated by output signals reflected from the duplexer and re-inputted to the power amplifier output
end. The maximum power of that can be inputted is 5W (Max) and IL is 0.65dB (Max). Input/output separation
is at least 15dB (Min).