![background image](http://html.mh-extra.com/html/samsung/sgh-d807-series/sgh-d807-series_service-manual_1190484013.webp)
SAMSUNG Proprietary-Contents may change without notice
Circuit Description
5-2
This Document can not be used without Samsung's authorization
- RX Function
●
Differential Low Noise Amplifiers
●
Direct Conversion mixer and IQ demodulator with 90 degree phase splitter.
●
Auto offset calibrated programmable gain amplifier with baseband filter(PGA)
- TX Function
●
I/Q modulator with 90 degree phase splitter
●
Offset PLL
- Phase comparator included fast lock system (Digital phase detector)
●
Polar loop
- Lineariser
- Voltage gain amplifier
- Inverse voltage gain amplifier
- Down converter
- AM detector
●
PLL Synthesiser
- RF Synthesiser for RX/TX RF local included fast lock system
- 400kHz comparison frequency to achieve faster lock-up time
5. POWER AMP (PAM406)
==> The PF09025B is a high-power, high-efficiency power amplifier module with in-
tegrated power control
●
Quad band Polar Loop Amplifier for GSM850 (824 to 849 MHz),
GSM900(880 to 915 MHz), DCS1800(1710 to 1785 MHz) and PCS1900
(1850 to 1910 MHz).
●
For 3.5 V normal operation
●
Built in LDO
●
Superb output linearity
●
High gain 3-stage amplifier : +5dBm input typical
●
GPRS / EGPRS Operation Compatible
●
Small package : 8.0 X 8.0 mm