LG VX8500 Service Manual page 30

VX8500
Pass Band 824~849 MHz
Insertion Loss
VSWR
Attenuation 40dB min (869~894MHz)
1.2.3 LNA (U107)
The RFR6500 has cellular, and PCS LNA, respectively. The characteristics of Low Noise
Amplifier (LNA) are low noise figure, high gain, high intercept point and high reverse isolation.
The frequency selectivity characteristic of mobile phone is mostly determined by LNA.
The specification of VX8500 LNA is described below:
Parameter Low gain
Cellular PCS
Gain -19
Noise Figure 19
Input IP3 25
1.2.4 GPS LNA(U103)
The characteristics of Low Noise Amplifier (LNA) are low noise figure, high gain, high intercept
point and high reverse isolation. The frequency selectivity characteristic of mobile phone is
mostly determined by LNA.
The specification of VX8500 GPS LNA is described below
Parameter
Gain
Noise Figure
1dB compression point
IIP3
1.2.5 RX RF SAW FILTER(F101, F102, F103)
The main function of RX RF SAW filter is to attenuate mobile phone spurious frequency,
attenuate noise amplified by the LNA and suppress second harmonic originating in the LNA.
LG Electronics Inc.
TX
2.5B max
2.2 max
Middle gain
Cellular PCS
-20 -2 -9
20 2 9
25 20 20
GPS Band
14.8
0.85
0
+5
37
RX
869~894 MHz
3.5dB max
2.3 max
50dB min
(824~849MHz)
High gain Units
Cellular PCS
15.5 16 dB
1.4 1.6 dB
6 8 dBm
Units
dB
dB
dBm
dBm
TX to RX (min)
54dB (824~849MHz)
43dB (869~894MHz)