NEC Confidential & Proprietary
6. POWER AMPLIFIER
TX power amplifier
A Tri band RF power amplifier (U111) is employed to this circuit. It has high-efficiency
output power 2W maximum for GSM900 band, and 1W maximum for DCS1800 band
and PCS1900 band. The power control function is also incorporated, eliminating the
need for directional couplers, detector diodes, power control ASICs and other power
control circuitry; this allows the module to be driven directly from the DAC output. The
VRAMP (TXP) is controlled the maximum power output and the power template as well as
power levels. On-board power control provides over 35dB of control range with an analog
voltage input; and, power down with a logic “low” for standby operation
The output is fed to the diplexer (U605) for sharing the antenna with Rx for duplex
operation.
Power &
Ramp control
From VCO
RF Power
O/P
Summary of Contents for N8
Page 1: ...N8 Service Manual Level 3 ...
Page 3: ...NEC Confidential Proprietary Next Section Main Menu Section 1 Precautions for Repair Work 1 ...
Page 24: ...NEC Confidential Proprietary PROGRAMMING CABLE Picture ...
Page 29: ...NEC Confidential Proprietary KEY SHEET ASSEMBLY ...
Page 30: ...NEC Confidential Proprietary INTER CONNECTION ...
Page 31: ...NEC Confidential Proprietary RF BLOCK DIAGRAM ...
Page 52: ...NEC Confidential Proprietary DATA CABLE ...
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Page 107: ...NEC Confidential Proprietary OUTLINE DIAGRAM TOP VIEW ...
Page 110: ...NEC Confidential Proprietary IC251 MAY YB0002 T001 PSC2011CHRS DT BLOCK DIAGRAM ...
Page 111: ...NEC Confidential Proprietary OUTLINE DIAGRAM TOP SEE THROUGH ...
Page 112: ...NEC Confidential Proprietary PIN INFORMATION ...
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Page 115: ...NEC Confidential Proprietary IC301 MAY YB0003 B001 TR09BFTGB17IN2B DB BLOCK DIAGRAM ...
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Page 133: ...NEC Confidential Proprietary U111 MAY YY0020 T001 RF3110 BLOCK DIAGRAM OUTLINE DIAGRAM ...
Page 134: ...NEC Confidential Proprietary PIN INFORMATION ...
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