galaxy h/w training - gprs rf part asus rd division ia department hw-2 group alan lin 2006/01/23
TRANSCRIPT
Galaxy H/W TrainingGalaxy H/W Training- GPRS RF Part- GPRS RF Part
ASUS RD DivisionASUS RD DivisionIA Department HW-2 GroupIA Department HW-2 GroupAlan LinAlan Lin2006/01/232006/01/23
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AgendaAgenda• Introduce to GPRS Function
- Block Diagram- Key Parts List- Aero II Architecture Highlights- Transmitter- Receiver
• Trouble Shooting- Ckt. & Location- AFC- APC- AGC
Introduce to GPRS FunctionIntroduce to GPRS Function
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GPRS Block DiagramGPRS Block Diagram
T/R SW
PA
RF Chip BB Chip
PMIC
Flash
RF Part
BB Part
PDA Part
FFUART
Analog IQ
Pink : GPRS RFGreen : GPRS Base-BandBlue : PDA
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Transceiver Block DiagramTransceiver Block Diagram
RF3166
850: 856441
900: 856387
1800: 856409
1900: 856417
LMSP33QA-321
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Base-band Block DiagramBase-band Block Diagram
3 wire bus for RF transceiver
RF Control T/R switch
Analog IQ signal
Audio RX path
Audio TX path
SIM
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Key Parts ListKey Parts List
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Aero II RX HighlightsAero II RX Highlights• Low IF architecture strengths (200kHz IF)
– Has advantages of Super-Heterodyne architectures :– DC Offsets are located outside the band of interest.– IP2 (AM Suppression) requirements are relaxed.– LO Self Mixing is not a problem.
– Has advantages of Direct Conversion architectures :– No IF SAW Filter required – Image Rejection
requirements are simplified.– Single analog down-conversion stage.– IF Analog Signal Processing is at a low frequency.
– Digital IF signal processing.
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Transceiver Functional Block Transceiver Functional Block RX SAW RX Loop
Universal Baseband Interface
(DAC)
Power Amp.
TX Loop
SynthesizerXTAL(DCXO)
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Receiver Block DiagramReceiver Block Diagram
Image Reject
Low - IF Receiver
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Low-IF ReceiverLow-IF Receiver
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Image RejectionImage Rejection
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Aero II TX HighlightsAero II TX Highlights
• Offset PLL architecture– Band Pass Noise Transfer Function attenuates noise in
RX band.– TXVCO is a constant-envelope signal that reduces the
problem of spectral spreading caused by non-linearity in the PA.
– Eliminates need for TX SAW Filter.
• TX transmit out buffer– Helps eliminate spurs and pulling issues.
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Transmitter Block DiagramTransmitter Block Diagram
Offset PLL
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Offset PLLOffset PLL- The OPLL acts as a tracking band-pass filter tuned to the
desired channel frequency. - The important difference between a PLL and the OPLL is
that the frequency modulation of the reference input is
reproduced at the output of the Tx-VCO without scaling
• Advantage - Low noise floor and spurs - Pulling of the transmit VCO is reduced -Truly constant envelope Output from VCO
• Disadvantage - Only possible with constant
envelope modulation scheme
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DCXO ArchitectureDCXO ArchitectureFrequency adjusted by two variable capacitances
- Cdac: coarse tuning
- Cafc: fine tuning
Trouble ShootingTrouble Shooting
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Measurement EquipmentMeasurement Equipment
• Agilent 8960 / CMU200
• Power Supply
• Scope
• Spectrum
• Passive Probe with DC Block
Spectrum Analyzer
I Q RF
GSM tester
Phone Tool
OscilloscopeDUT
Data cable
RF adaptor
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Base Station SetupBase Station Setup
• Base Station Test Mode Setup
GSM850 EGSM DCS PCSMode BCH + TCH BCH + TCH BCH + TCH BCH + TCH
BS Power -60dBm, -20dBm -60dBm, -20dBm -60dBm, -20dBm -60dBm, -20dBmBCH 190 62 700 661TCH 190 62 700 661
TX PCL 5, 19 5, 19 0, 15 0, 15
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Antenna Switch ConnectorAntenna Switch Connector
Antenna Switch Connector
Bottom Side
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PA & Front-endPA & Front-endTop Side
T/R Switch
High band Matching
PA
Low band Matching
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PA & Front-endPA & Front-end
PALEVEL (VRAMP)
High bandMatching
Low bandMatching
T/R Switching
PA
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RX PathRX PathTop Side
T/R Switch
RX SAW
Transceiver
XTAL
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RX PathRX Path
RX SAW
RX SAWT/R Switching
Transceiver
XTAL
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T/R Control TableT/R Control Table
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Trouble ShootingTrouble Shooting
• AFC Fail• APC Fail• AGC Fail• ORFS due to Modulation Fail
@ -200kHz & +400kHz fail• Others
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AFC & TX Testing NodesAFC & TX Testing NodesA
B
CD
EF
H
G
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AFC FailAFC Fail• Check antenna switch connector• Check Vramp & PA output power• Check 26MHz output
PA
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APC FailAPC Fail• If TX current is right
- Check antenna switch connector - Check T/R switch- Check PA matching circuit
T/R SW
Low-band in
Low-band out
VrampHigh-band in
High-band out
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APC FailAPC Fail• If TX current is small
- Check TXVCO output- Check Vramp- Check PA- Check VBAT
T/R SW
Low-band in
Low-band out
VrampHigh-band in
High-band out
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AFC & TX SignalsAFC & TX Signals
Node Description Value Fig.A XOUT at C957 26MHz, 1.6V 1.1B TXIQ 4.6ms, 1.2V(max) 1.2C TXVCO at C947(GSM850/EGSM) PCL : 19, 902.4MHz ref. 1.3D TXVCO at C944 (DCS/PCS) PCL : 15, 1747.8MHz 1.3E Power at T/RSW(C930) Low-band in PCL : 19, 902.4MHz ref. 1.4F Power at T/RSW(C933) High-band in PCL : 15, 1747.8MHz 1.4
G Power at C946PCL : 19, 902.4MHzPCL : 15, 1747.8MHz
1.4
H VrampEGSM : 1.3V (PCL5), 0.3V (PCL19)DCS : 1.28V (PCL0), 0.3V (PCL15) 1.5
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26MHz & TXIQ26MHz & TXIQ
Fig. 1.1 26MHz
Fig. 1.2 TXIQ
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TXVCOTXVCO
Fig. 1.3 TXVCO DCS Ch700 : 1747.8MHz
Fig. 1.4 PA Out DCS Ch700 : 1747.8MHz
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Vramp Vramp
Fig. 1.5 Vramp
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RX Testing NodesRX Testing Nodes
A
BE
D
C
F
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AGC FailAGC Fail• Check antenna switch connector• Check T/R switch• Check SAW• Check RXIQ
RX SAW
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RX SignalsRX Signals
Node Description Value Fig.A XOUT at C957 26MHz, 1.6V 2.1B Power at C946 EGSM Ch62 : 947.4MHz, BS: -20dBm ref. 2.2C Power at EGSM SAW out EGSM Ch62 : 947.4MHz, BS: -20dBm 2.2D Power at DCS SAW out DCS Ch700 : 1842.8MHz, BS: -20dBm ref.2.2E Power at PCS SAW out PCS Ch661 : 1960MHz, BS: -20dBm ref.2.2F RXIQ EGSM Ch62 : 947.4MHz, BS: -20dBm 2.3
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26MHz & T/R Switch Out26MHz & T/R Switch Out
Fig. 2.1 26MHz Fig. 2.2 EGSM Ch62 : 947.4MHz
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RX IQRX IQ
Fig. 2.5 RX IQ