Nokia ra8 RF Description and Troubleshooting
Nokia Customer Care
7 - RF Description and
Troubleshooting
Issue 1 11/05 COMPANY CONFIDENTIAL
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
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Issue 1 11/05 COMPANY CONFIDENTIAL 2
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
Table of Contents
Page No
CMT RF................................................................................................................. 5
Top-level description.......................................................................................... 5
RA-8 test point locations................................................................................... 6
Test points ......................................................................................................... 7
RF implementation in RA-8.............................................................................. 11
Frequency plan ..............................................................................................11
RF block diagram ...........................................................................................12
Antenna switch module (ASM) .......................................................................13
DC characteristics ..........................................................................................13
RF characteristics ............................................................................................ 16
Channel numbers and frequencies ................................................................ 16
RF Troubleshooting..........................................................................................17
Receiver description and troubleshooting........................................................ 17
Rx front end ...................................................................................................17
Antenna .........................................................................................................17
Receiver characteristics .................................................................................18
General instructions for Rx troubleshooting ...................................................19
Transmitter description and troubleshooting.................................................... 26
Power amplifier ..............................................................................................26
RF ASIC Honi ................................................................................................26
AFC function ..................................................................................................27
Transmitter characteristics .............................................................................27
General instructions for Tx troubleshooting ................................................... 27
Additional information for EDGE troubleshooting ............................................ 34
Pictures of EDGE transmitter signals .............................................................38
Synthesizer description and troubleshooting................................................... 42
Frequency synthesizers .................................................................................42
General instructions for synthesizer troubleshooting .....................................42
Frequency Lists ..............................................................................................47
RF tunings after repairs ................................................................................... 50
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RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
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4 COMPANY CONFIDENTIAL Issue 1 11/05
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RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
CMT RF
■ Top-level description
The RF module performs the necessary high frequency operations of theEGSM900/1800/1900
tripleband (EDGE) engine. Both the transmitter and receiver have been implemented by using
direct conversion architecture which means that the modulator and demodulator operate at the
channel frequency.
The core of the RF is an application-specific integrated circuit, Honi. Another co re component
is a power amplifier module which includes two amplifier chains, one fo r EGSM900 and the other for GSM1800/GSM1900.
Other key components include
• 26 MHz VCTCXO for frequency reference
• 3296-3980 MHz SHF VCO (super high frequency voltage controlled oscillator)
• Antenna switch module (ASM)
• Three SAW filters
• BAW-LNA module
The control information for the RF is coming from the baseband section of the engine through
a serial bus, referred later on as RFBus.
The whole RF circuitry is located on one side of the 8-layer PWB.
EMC leakage is prevented by using a metal shield with gasket. The RF circuits are separated
into two blocks.
• PA, ASM, TK balun
• Honi RF IC, VCO + balun, VCTCXO, BAW-LNA, Rx filter, Tx filter
The RF transmission lines constitute of striplines and microstriplines after PA.
Issue 1 11/05 COMPANY CONFIDENTIAL 5
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RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
■ RA-8 test point locations
Figure 1: Top view
J7510
J7510
J7510
TXQM
TXQM
TXQM
J7511
J7511
J7511
TXIM
TXIM
TXIM
J7503
J7503
J7503
RFBusClk
RFBusClk
RFBusClk
J7512
J7512
J7512
TXIP
TXIP
TXIP
J7501
J7501
RXQ
RXQ
J7504
J7504
J7504
RFBusEna1
RFBusEna1
RFBusEna1
J7502
J7502
J7502
RFBusData
RFBusData
RFBusData
J7508
J7508
TXC
TXC
L7603
L7603
Z7601
Z7601
L7602
L7602
L7601
L7601
Z7602
Z7602
R7503
R7503
L7604
L7604
R7602
R7602
Z7603
Z7603
R7500
R7500
G7500
G7500
C7506
C7506
C7505
C7505
J7500
J7500
RXI
RXI
G7501
G7501
J7509
J7509
J7509
TXQP
TXQP
TXQP
L7500
L7500
C7516
C7516
R7601
R7601
C7706
C7706
C7705
C7705
C7721
C7721
Z7600
Z7600
C7702
C7702
R7705
R7705
R7707
R7707
R7710
R7710
R7712
R7712
J7506
J7506
J7506
TXA
TXA
TXA
J7505
J7505
J7505
Reset
Reset
Reset
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Figure 2: Bottom view
J7507
TXP
RF test
connection
■ Test points
Table 1: Rx test points
Signal name: Ref:
LNAB_P Z7603
LNA_P Z7603
RXI J7500
RXQ J7501
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Nokia Customer Care 7 - RF Description and Troubleshooting
Table 2: Antenna switch test points
Signal name: Ref:
VANT_1 Z7600
VANT_2 Z7600
VANT_3 Z7600
GSM_Rx Z7600
DCS_Rx Z7600
PCS_Rx Z7600
TX_IN_EGSM Z7600
Table 3: Honi serial interface test points
Signal name: Ref:
RFBusClk J7503
RFBusEna1 J7504
RFBusData J7502
Reset J7505
Table 4: Synthesizer test points
Signal name: Ref:
VCO_out G7500
VCTCXO_out G7501
Table 5: GSM900 Rx Honi input test points
RX filter Z7601
Ref:
Inductor L7603
Inductor L7604
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Table 6: GSM1800 Rx Honi input test points
Ref:
Filter Z7602
Inductor L7601
Inductor L7602
Table 7: GSM1900 Rx Honi input test points
Ref:
BAW-LNA Z7603 pin 7
Resistor R7601
Resistor R7602
Table 8: Tx PA input test points
Signal name: Ref:
Rfin_900 R7705
Rfin_1800/190 R7710
Table 9: Tx filter/balun input test points
Signal name: Ref:
RfinP_900 C7721
RfinM_900 C7721
RfinP_1800_1900 C7705
RfinM_1800_1900 C7706
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Nokia Customer Care 7 - RF Description and Troubleshooting
Table 10: PA control signal test points
Signal name: Ref:
VPCTRL_900 R7707
VPCTRL_1800_1900 R7712
TXIM J7511
TXIP J7512
TXQM J7510
TXQP J7509
TXC J7508
TXP J7507 (test pad)
TXA J7506
Table 11: Rx test points
Signal name: Ref:
VR1
VR2 C7516
VR3 L7500
VR4
VR5 C7505
VR6 C7506
VR7 R7500
VrefRF01 R7503
VBAT C7702
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■ RF implementation in RA-8
Frequency plan
The RF frequency plan is shown below. The VCO operates at the channel fre quency multiplied
by two or four depending on the frequency band of operation. This means that the baseband
modulated signals are directly converted up to the transmission frequency and the received RF
signals directly down to the baseband frequency.
Figure 3: RF frequency plan
HONI
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Nokia Customer Care 7 - RF Description and Troubleshooting
RF block diagram
IN
Antenna
IN
OUT2
OUT1
Front end
INOUT
INOUT
AGC
PCS1900
1
3
BAW-LNA
2
5
4
INOUT
SAW
DCS1800
INOUT
RF
IF
RF
LO
LO
IF
INOUT
AGC
RF
LO
IF
module
OUT1
RF
IF
IN
SAW
IN
IN OUT
OUT2
OUT1
INOUT
IN OUT
INOUT
BIAS
IN OUT
Mode (GSM/EDGE)
IN OUT
OUT2
OUT1
IN
OUT2
EGSM 900
INOUT
AGC
RF
LO
IF
f/2
OUT
f
IN
RF
LO
LO
IF
OUT
f
IN
AGC
IN OUT
AGC
IN OUT
IN OUT
AGC
IN OUT
AGC
IN OUT
1
2
5
3
4
f/4
AGC
IN OUT
AGC
IN OUT
IPA2
IPA1
INOUT
BIAS
Pwr det
Power amplifier
INOUT
HONI
INOUT
HONI
INOUT
AGC
INOUT
INOUT
AGC
IN
MODPLL
VCO
SYNT_MIX
RX-MIX
1
2
5
3
INOUT
INOUT
IN OUT
IN
4
3420 - 3980 MHz
INOUT
EGSM900
DtoS
INOUT
AGC
INOUT
INOUT
AGC
PLL
OUT
REF LE1 CLK DATA
12 dB
AGC
f
IN
IN OUT
f
OUT1
42 dB / 6dB step
VCTCXO
26 Mhz
IN
OUT2
f/2
OUT
IN
OUT1
OUT2
IN
OUTAFC
INOUT
f/4
OUT
IN OUT
RF
LO
IF
f
IN
15 dB
OUT
RF
LO
IF
CNTR
IN OUT
TXP
TXP
OUT
OUT
DCS1800/PCS1900
IN
TXC
f/2
RF
LO
IF
IN
TXC
AGC
15 dB
IN OUT
RF
LO
IF
RXI
RXQ
AFC
Sys.clock
Data
Clock
Reset
Enable
TXIP
TXIM
TXQP
TXA
TXQM
TXP
TXC
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Antenna switch module (ASM)
Figure 4: ASM
DC characteristics
Regulators
The transceiver baseband section has a multi function analog ASIC, UEM, which contains
among other functions six pieces of 2.78 V linear regulators and a 4.8 V switch ing regulator. All
the regulators can be controlled individually by the 2.78 V logic directly or through a control register. Normally, direct control is needed because of switching speed requirement: the regulators are used to enable the RF-functions which means that the controls must be fast enough.
The use of the regulators can be seen in the power distribution diagram which is p resented in
Figure 6, “Power distribution diagram,” on page 15.
The seven regulators are named VR1 to VR7. VrefRF01 is used as a reference voltage for Honi.
The regulators (except for VR7) are connected to the Honi. Different modes of operation can
be selected inside the Honi according to the control information coming through the RFBus.
Issue 1 11/05 COMPANY CONFIDENTIAL 13
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Nokia Customer Care 7 - RF Description and Troubleshooting
DC supply currents
Figure 5: DC power supplies
Typical current consumption
The table shows the typical current consumption in different operation modes.
Operation mode
Power OFF < 10 uA Leakage current (triple band PA)
Rx, EGSM900 75 mA, peak
Rx, GSM1800/GSM1900 70 mA, peak
Tx, power level 5, EGSM900 1700 mA, peak
Tx, power level 0, GSM1800/
GSM1900
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1000 mA, peak
Current
consumption
Notes
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7 - RF Description and Troubleshooting Nokia Customer Care
Power distribution diagram
Figure 6: Power distribution diagram
Honi
LNA
GSM1900
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