Nokia RA-8 Guide

Issue 1 11/05 COMPANY CONFIDENTIAL
Copyright © 2005 Nokia. All Rights Reserved.
Nokia Customer Care
7 - RF Description and
Troubleshooting

Issue 1 11/05 COMPANY CONFIDENTIAL 2
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 3
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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Nokia Customer Care 7 - RF Description and Troubleshooting
4 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
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Issue 1 11/05 COMPANY CONFIDENTIAL 5
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
CMT RF
■ Top-level description
TheRFmoduleperformsthenecessaryhighfrequencyoperationsoftheEGSM900/1800/1900
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 core component
is a power amplifier modulewhich includes two amplifier chains, one for EGSM900 andthe oth-
er 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.

RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
6 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
■ RA-8 test point locations
Figure 1: Top view
Z7601
L7602
J7500
RXI
J7508
TXC J7501
RXQ
J7509
TXQP J7512
TXIP
J7511
TXIM
J7510
TXQM
J7503
RFBusClk
J7504
RFBusEna1
J7502
RFBusData
J7506
TXA J7505
Reset
Z7603
Z7600
G7500
G7501
L7603
L7604
Z7602
L7601
R7601
R7602
R7705 R7710
C7721
C7705
C7706
R7707 R7712
C7516
L7500
C7505
C7506
R7500
R7503
C7702
Z7601
L7602
J7500
RXI
J7508
TXC J7501
RXQ
J7509
TXQP J7512
TXIP
J7511
TXIM
J7510
TXQM
J7509
TXQP J7512
TXIP
J7511
TXIM
J7510
TXQM
J7503
RFBusClk
J7504
RFBusEna1
J7502
RFBusData
J7503
RFBusClk
J7504
RFBusEna1
J7502
RFBusData
J7506
TXA J7505
Reset
J7506
TXA J7505
Reset
Z7603
Z7600
G7500
G7501
L7603
L7604
Z7602
L7601
R7601
R7602
R7705 R7710
C7721
C7705
C7706
R7707 R7712
C7516
L7500
C7505
C7506
R7500
R7503
C7702

Issue 1 11/05 COMPANY CONFIDENTIAL 7
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
Figure 2: Bottom view
■ Test points
Table 1: Rx test points
Signal name: Ref:
LNAB_P Z7603
LNA_P Z7603
RXI J7500
RXQ J7501
J7507
TXP
RF test
connection

RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
8 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
Table 2: Antenna switch test points
Table 3: Honi serial interface test points
Table 4: Synthesizer test points
Table 5: GSM900 Rx Honi input 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
Signal name: Ref:
RFBusClk J7503
RFBusEna1 J7504
RFBusData J7502
Reset J7505
Signal name: Ref:
VCO_out G7500
VCTCXO_out G7501
Ref:
RX filter Z7601
Inductor L7603
Inductor L7604

Issue 1 11/05 COMPANY CONFIDENTIAL 9
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RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
Table 6: GSM1800 Rx Honi input test points
Table 7: GSM1900 Rx Honi input test points
Table 8: Tx PA input test points
Table 9: Tx filter/balun input test points
Ref:
Filter Z7602
Inductor L7601
Inductor L7602
Ref:
BAW-LNA Z7603 pin 7
Resistor R7601
Resistor R7602
Signal name: Ref:
Rfin_900 R7705
Rfin_1800/190 R7710
Signal name: Ref:
RfinP_900 C7721
RfinM_900 C7721
RfinP_1800_1900 C7705
RfinM_1800_1900 C7706

RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
10 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
Table 10: PA control signal test points
Table 11: Rx 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
Signal name: Ref:
VR1
VR2 C7516
VR3 L7500
VR4
VR5 C7505
VR6 C7506
VR7 R7500
VrefRF01 R7503
VBAT C7702

Issue 1 11/05 COMPANY CONFIDENTIAL 11
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
■ RF implementation in RA-8
Frequency plan
The RF frequency plan is shownbelow. The VCO operates at the channel frequency 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

RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
12 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
RF block diagram
VCOIN
MODPLL
RX-MIX
SYNT_MIX
2
1
3
5
4
OUTAFC
VCTCXO
IN OUT
f/2
f
INOUT
INOUT
AGC
INOUT
AGC
INOUT
INOUT
AGC
INOUT
AGC
DtoS
12 dB
42 dB / 6dB step
INOUT IN
OUT PLL
REF LE1 CLK DATA
IN
OUT2
OUT1
IN OUT2
OUT1
IN OUT
IN
OUT
f/2
f
IN
OUT2
OUT1
RF
LO
IF
RF
LO
IF
IN OUT
AGC
IN
OUT
f/2
f
RF
LO
IF
RF
LO
IF
IN OUT
AGC
IN
OUT
f/4
f
IN OUT
f/4
f
RF
LO
IF
RF
LO
IF
INOUT
INOUT
AGC
INOUT
AGC
RF
LO
IF
RF
LO
IF
RF
LO
IF
RF
LO
IF
IN OUT
AGC
IN OUT
AGC
IN OUT
TXP
TXC
IN OUT
TXP
TXC
IN OUT
CNTR
EGSM900
RXI
RXQ
26 Mhz
AFC
Sys.clock
Data
Clock
Enable
Reset
TXIP
TXIM
TXQP
TXQM
TXA TXP
TXC
15 dB
15 dB
DCS1800/PCS1900
3420 - 3980 MHz
HONI INOUT
AGC
2
1
3
5 4
PCS1900
2
1
3
5
4
IN OUT
IN OUT
AGC
IN OUT
AGC
INOUT
BIAS
IN OUT
IN OUT
AGC
IN OUT
AGC
INOUT
BIAS
Pwr det
Power amplifier
IN
IN
OUT2
OUT1
IN
OUT2
OUT1
IN
OUT2
OUT1
IPA2
IPA1
Mode (GSM/EDGE)
DCS1800
SAW
Front end
module
Antenna
INOUT
INOUT
INOUT INOUT
INOUT
IN OUT
IN OUT IN OUT
IN OUT
INOUT
INOUT
INOUT
SAW
EGSM 900
BAW-LNA
HONI

Issue 1 11/05 COMPANY CONFIDENTIAL 13
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
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 anda 4.8 V switching regulator.All
the regulators can be controlled individually by the 2.78 V logic directly or through a control reg-
ister. Normally, direct control is needed because of switching speed requirement: the regula-
tors 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 presented 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 Ho-
ni.
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.

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Nokia Customer Care 7 - RF Description and Troubleshooting
14 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
DC supply currents
Figure 5: DC power supplies
Typical current consumption
The table shows the typical current consumption in different operation modes.
Operation mode Current
consumption Notes
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 1000 mA, peak

Issue 1 11/05 COMPANY CONFIDENTIAL 15
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
Power distribution diagram
Figure 6: Power distribution diagram
Honi
LNA
GSM1900

RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
16 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
■ RF characteristics
Channel numbers and frequencies
System Channel number TX frequency RX frequency Unit
EGSM 0 <= n <=124 F = 890 + 0.2 * n F = 935 + 0.2 * n MHz
975 <= n <= 1023 F= 890+0.2* (n -1024) F= 935+0.2* (n -1024) MHz
DCS1800 512 <= n <= 885 F=1710.2+0.2*(n-512) F=1805.2+0.2*(n-512) MHz
PCS1900 512 <= n <=810 F=1850.2+0.2*(n-512) F=1930.2+0.2*(n-512) MHz

Issue 1 11/05 COMPANY CONFIDENTIAL 17
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
RF Troubleshooting
All measurements should be done using a spectrum analyzer with a high-frequency high-im-
pedance passive probe (LO-/reference frequencies and RF power levels) and an oscilloscope
with a 10:1 probe (DC-voltages and low frequency signals).
The RF section is build around one RF ASIC (Honi N7500). For easier troubleshooting, this RF
troubleshooting document is divided into sections.
Before changing Honi, please check that both supply voltages and serial communication com-
ing from baseband to Honi are OK. Please note that the grounding of the PA module is directly
below the PA module, so it is difficult to check or change.
Most RF semiconductors are static discharge sensitive! Therefore ESD protection must be tak-
en care of during repair (ground straps and ESD soldering irons). Honi and PA are moisture
sensitive and thus must be handled as described in the Special Component Handling Docu-
ment.
Apart from key components described in this document there are a lot of discrete components
(resistors, inductors and capacitors) of which troubleshooting is done by checking if the solder-
ing of the component is done properly (for factory repairs checking if it is missing from the
PWB). You can check capacitors for shortening and resistors for value by means of an ohm-
meter, but be aware in-circuit measurements should be evaluated carefully.
Please be aware that all measured voltages or RF levels in this document are rough figures.
Especially RF levels vary due to different measuring equipment or different grounding of the
probe used. When using an RF probe use a pair of metallic tweezers to connect the probe
ground to the PWB ground as close to the measurement point as possible.
■ Receiver description and troubleshooting
Each receiver path is a direct conversion linear receiver. From the antenna, the received RF-
signal is fed to a front end module where a diplexer first divides the signal into two separate
paths according to the band of operation: either lower, EGSM900 or upper, GSM1800/
GSM1900 path.
Most of the receiver circuitry is included in Honi.
Rx front end
The front end features include:
• Antenna 50 ohm input
• RXs single outputs
• TXs single 50 ohm inputs
• 3 control lines from Honi
Antenna
The RA-8 EGSM900/GSM1800/GSM1900 transceiver features an internal antenna.

RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
18 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
Receiver characteristics
Item Values (GSM900/1800/1900)
Type Direct conversion, Linear, FDMA/TDMA
LO frequencies 3700...3840 MHz / 3610...3760 MHz /
3860…3980 MHz
Typical 3 dB bandwidth +/- 91 kHz
Sensitivity min. - 102 dBm
Total typical receiver voltage gain (from
antenna
to RX ADC )
86 dB
Receiver output level (RF level -95 dBm ) 230 mVpp, single-ended I/Q signals to RX
ADCs
Typical AGC dynamic range 83 dB
Accurate AGC control range 60 dB
Typical AGC step in LNA 30 dB GSM1800/GSM1900, 25 dB GSM900
Usable input dynamic range -102 ... -10 dBm
RSSI dynamic range -110 ... -48 dBm
Compensated gain variation in receiving
band +/- 1.0 dB

Issue 1 11/05 COMPANY CONFIDENTIAL 19
Copyright © 2005 Nokia. All Rights Reserved.
RA-8
7 - RF Description and Troubleshooting Nokia Customer Care
General instructions for Rx troubleshooting
To start Rx troubleshooting:
1. Connect test jig to a computer with a DAU-9S cable or to a FPS-8 flash prom-
mer with an XCS-4 modular cable.
Make sure that you have PKD-1 dongle connected to the computer’s parallel port.
2. Connect a DC power supply to the module test jig with an FLC-2 cable.
3. Set the DC supply voltage to 6 V.
4. Connect an RF cable to the RF connector of the module test jig (MJ-83) and to
RF signal generator.
5. Set the phone module to test jig and start Phoenix service software.
6. Initialize connection to the phone. (Use FBUS driver when using DAU-9S and
COMBOX driver when using FPS-8).
7. From the File menu, choose “Choose Product”.
8. From the list, select RA-8.
9. From the toolbar, set operating mode to "Local".
10.From the Testing menu, choose “RF Controls”.
11.In the “RF Controls” window:
- Select band “GSM 900", "GSM 1800" or “GSM1900” (Default = "GSM900")
- Set Active unit to "Rx" (Default = "Rx")
- Set Operation mode to "Burst" (Default = "Burst")
For continuous mode:
- Set Operation mode to "Continuous"
- Set AGC to "12: FEG_ON + DTOS_ON + BB_30=Vgain60” (maximum gain set-
ting used in normal mode) (Default = "14: FEG_ON + DTOS_ON +
BB_42=Vgain72")
- Set Rx/Tx channel to 37 on GSM900 band, 700 on GSM1800 band or 661on
GSM1900 (Defaults)
12.Apply
942.46771 MHz (channel 37 + 67.710 kHz offset),
1842.86771 MHz (channel 700 + 67.710 kHz offset) or
1960.06771 MHz (channel 661 + 67.71 kHz) –90 dBm signal
to the RF connector (remember to compensate for cable attenuation).
When measuring with an oscilloscope on "RXI" or "RXQ", you should see the fol-
lowing screens on a working GSM900, GSM1800 or GSM1900 receiver:

RA-8
Nokia Customer Care 7 - RF Description and Troubleshooting
20 COMPANY CONFIDENTIAL Issue 1 11/05
Copyright © 2005 Nokia. All Rights Reserved.
Figure 7: Rx I/Q signal, burst mode, input level –90dBm
• Receiver I or Q burst mode signal (channel 37) measured from test point RXI
or RXQ with 942.46771 MHz signal, input level –90dBm at RF-connector.
Correct signal amplitudes approximately:
GSM900~170mVpp
GSM1800~140mVpp
GSM1900~160mVpp
Signal part frequency 67.7kHz sine.
DC level of signal part is 1.35V. DC level can vary about +/-100mV between I