LG VX8500 Service Manual page 32

VX8500
RFT6150 Cellular and PCS CDMA RF Specifications
Parameter
Rated Output Power
Min Output Power
RX band noise power
ACPR
1.3.2 Power Amplifier(U106)
The Dual power amplifier that can be used in the PCS and CDMA mode has linear amplification
capability and 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
+17dBm and conversion gain is about 28dB. RF transmit signals that have been amplified
through the power amplifier are sent to the duplexer.
.
1.4 Description of Frequency Synthesizer Circuit
1.4.1 Voltage Control Temperature Compensation Crystal Oscillator (VCTCXO, X100)
The temperature variation of mobile phone can be compensated by VCTCXO. The reference
frequency of a mobile phone is 19.2 MHz.
TRK_LO_ADJ from MSM as 0.5 V~2.5 V DC via R and C filter in order to generate the reference
frequency of 19.2 MHz and input it into the frequency synthesizer.
depending on temperature is ±2.0 ppm.
LG Electronics Inc.
Condition
Average CDMA Cellular
Average CDMA PCS
Average CDMA Cellular
Average CDMA PCS
CDMA Cellular
CDMA PCS
Cellular: Fc±885kHz
PCS : Fc±1.25MHz
The receiver frequency tuning signals called
39
Min. Type. Max.
8
10
-80
-78
-133
-132
-56
-56
Frequency stability
Units
dBm
dBm
dBm
dBm
dBm/Hz
dBc/
30kHz