LG U300 Service Manual page 29

3. TECHNICAL BRIEF
- Power handling . high power levels in the transmit path must be accommodated without degraded
performance. The specified level depends on the operating band class and mobile station class (per
the applicable standard), as well as circuit losses and antenna EIRP. Several duplexer characteristics
depend upon its source and load impedances. QUALCOMM strongly recommends an isolator be used
between the UMTS PA and duplexer to assure proper performance.
3.5.3 UMTS Power Amplifier (U104)
The RF5198 is a high-power, high-efficiency linear amplifier module specifically designed for 3V
handheld systems.
The device is manufactured on an advanced third generation GaAs HBT process, and was designed
for use as the final RF amplifier in 3V W-CDMA handheld digital cellular equipment, spread-
spectrum systems, and other applications in the 1920MHz to 1980MHz band. The RF5198 has a
digital control line for low power applications to lower quiescent current. The RF5198 is assembled in
at 16-pin, 3mmx3mm, QFN package.
Features
• Input/Output Internally Matched@50Ω
• 27.5dBm Linear Output Power
• 42% Peak Linear Efficiency
• 28dB Linear Gain
• -41dBc ACLR @ ± 5MHz
• Integrated Power Detector
Figure3.5.3-1 UMTS PA functional block diagram
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