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Nokia NPM-10 Series Troubleshooting Instructions Download Page 8

NPM-10

Troubleshooting Instructions RF

CCS Technical Documentation

Page 8

 

Nokia Corporation          Confidential

Issue 1 03/2003

Figure 2: Transmitter signal path

PLL

The PLL supplies Local Oscillator (LO) signals for the RX and TX mixers. In order to be able 
to generate LO frequencies for the required GSM and PCS channels, a regular Synthesizer 
circuit is used. All PLL blocks except for the VCO, reference X-tal, and loop filter are 
located in the Mjoelner IC.

The reference frequency is generated by a 26MHz Voltage Controlled X-tal Oscillator 
(VCXO), which is located in Mjoelner. Only the X-tal is external. 26MHz is supplied to BB 
where a divide-by-2 circuit (located in the UPP IC) generates the BB clock at 13MHz. The 
reference frequency is supplied to the reference divider (RDIV) where the frequency is 
divided by 65. The output of RDIV (400kHz) is used as reference clock for the Phase 
Detector (

ϕ

).

The PLL is a feedback control system controlling the phase and frequency of the LO sig-
nal. Building blocks for the PLL are: Phase detector, Charge Pump, Voltage Controlled 
Oscillator (VCO), N-divider, and loop filter. As mentioned earlier only the VCO, reference 
X-tal, and loop filter are external to the Mjoelner IC. 

The VCO (G600) is the component that actually generates the LO frequency. Based on the 
control voltage input, the VCO generates a differential RF output. This signal is fed to the 
Prescaler and N-divider in Mjoelner, these two blocks will together divide the frequency 

1/2

1/4

OUTHP

OUTHM

OUTLP

OUTLM

PWC

DET

VB_DET

VANTL / VANTM

PA

N700

Dir.

coupler

TXC

TXP

VBATTRF

PCS

V701

GSM

V702

VTXLOL

TXI

P

/

TXI

M

TXQP/

TXQM

2

2

2

2

2

2

2

PLFB1

PLFB2

VPCH/VPCL

2

SAW  Z603

VTX

VTX

TXC

TXP

V

DDT

X

Supply

filter

VR2

VTXBH

VTXBL

VANTH

VDDDIG

VTXLOH

VDDRXBB

DET

RF

Controls

RF

Controls

Buffer

Balun

Loop

filter

Ant.

switch

Z700

RX

RX

TX

TX

PCN

GSM

2

Mjoelner

N600

L709

L704

Buffer

Summary of Contents for NPM-10 Series

Page 1: ...CCS Technical Documentation NPM 10 Series Transceivers Issue 1 03 2003 Confidential Nokia Corporation Troubleshooting Instructions RF ...

Page 2: ...NPM 10 Troubleshooting Instructions RF CCS Technical Documentation Page 2 Nokia Corporation Confidential Issue 1 03 2003 ...

Page 3: ...eshooting Chart for PCS Receiver 18 Measurement Points in the Receiver 20 Transmitter 22 Measurement Points for the Transmitter 22 General Instructions for GSM TX Troubleshooting 23 Troubleshooting Chart for GSM850 Transmitter 24 General instructions for PCS TX troubleshooting 26 Synthesizer 29 General Instructions for Synthesizer Troubleshooting 29 26 MHz Reference Oscillator VCXO 30 VCO 30 Troub...

Page 4: ...NPM 10 Troubleshooting Instructions RF CCS Technical Documentation Page 4 Nokia Corporation Confidential Issue 1 03 2003 ...

Page 5: ...tter UHF Ultra High Frequency VCO Voltage Controlled Oscillator Introduction Two types of measurements are used in the following It will be specified if the measure ment type is RF or LF RF measurements should be done with a Spectrum Analyzer with a high impedance probe Note Signal levels can vary depending on measurement setup therefore it is recommended that a known good phone is used as a bench...

Page 6: ...checked for short circuiting and resistors for value by means of an ohmmeter but be aware that in circuit measurements should be evaluated carefully In the following both the name GSM and GSM850 will be used for the lower band and both PCS and GSM1900 will be used for the upper band General Description of the RF Circuits In the following general descriptions different colors are used in the block ...

Page 7: ...tion The GSM1900 signal chain is similar to GSM850 the SAW filter numbered Z601 Transmitter Signal Path The I Q signal from the BB is routed to the modulators for both 850 MHz and 1900 MHz The output of the modulators is either terminated in a SAW filter Z603 for GSM850 or a balun T602 for GSM1900 Both signals are amplified in buffers which are operated in a soft compression region to suppress som...

Page 8: ...V 400kHz is used as reference clock for the Phase Detector ϕ The PLL is a feedback control system controlling the phase and frequency of the LO sig nal Building blocks for the PLL are Phase detector Charge Pump Voltage Controlled Oscillator VCO N divider and loop filter As mentioned earlier only the VCO reference X tal and loop filter are external to the Mjoelner IC The VCO G600 is the component t...

Page 9: ...z VCXO frequency The loop filter consists of the following components C639 C641 and R618 R619 The PLL is operating at twice the channel center frequency when transmitting or receiv ing in the PCS band For the GSM band the PLL is operating at four times the channel frequency Therefore divide by 2 and divide by 4 circuits are inserted between the PLL output and LO inputs to the PCS and GSM mixers Th...

Page 10: ... 26MHz RBEXT VXO RF_EN RF_CLK RF_DATA RESETX_Mjoel 1 2 Buffer VBEXT LOCNT REFCNT Lock Detect 2 XTALM XTALP REFOUT REFOUT 26MHz VPLL VDDCP VDDPRE VDDLO VDDPLL VDDXO VREF1 VDDDL VDDDIG VDDBBB VBB 1 8V Digital Control 2 7k Vcp supply filter SENSE RESETX INPLO INMLO VVCO VCO G600 Rpa Ref filter 3 RFBUSX RFBUSDA RFBUSCLK Synth supply filter Ref clk set VCXO supply filter VR5 VR3 VR7 RFCONV_0 9 VIO VCOS...

Page 11: ...igure 4 Key Component Locations Power Supply Configuration All power supplies for the RF Unit are generated in the UEM IC D200 All power outputs from this IC have a decoupling capacitor at which the supply voltage can be checked The power supply configuration used in the 3595 phone is shown in the block diagram that follows ...

Page 12: ...lowing graphic for measuring points at the UEM D200 Table 3 Power Supply Details Supply name RF Supply name UEM Min Typ Max Unit VTX VR2 2 64 2 78 2 86 V VXO VR3 2 64 2 78 2 86 V VCP VR1A 4 75 V VPLL VR5 2 64 2 78 2 86 V VRX VR6 2 64 2 78 2 86 V VVCO VR7 2 64 2 78 2 86 V VBB VIO 1 72 1 8 1 88 V VREF2 VrelRF01 1 334 1 35 1 366 V VBATT BATTERY 3 1 3 6 5 2 V VR2 VR3 VR5 VR6 VR7 VIO Vref01 Battery UEM...

Page 13: ...points at the UEM D200 Figure 7 Supply point at the Mjoelner N600 Receiver General Instructions for GSM850 RX Troubleshooting Connect the phone to a PC with the module test jig Start Phoenix and establish connection to the phone Select File VR2 Vtx C643 VR5 Vpll C226 VR3 Vvcxo C227 VR6 Vrx C225 Vref01 Vref2 C231 VR7 Vvco C224 Vio Vbb C621 ...

Page 14: ...l Documentation Page 14 Nokia Corporation Confidential Issue 1 03 2003 Scan for Product Ctrl R Select Maintenance Testing RF Controls Select The setup should now look like this Band GSM850 Active Unit RX Operation Mode Continuous Rx Tx Channel 190 AGC 9 ...

Page 15: ... 881 6 MHz offset 67 71 kHz from generator to antenna connector Oscilloscope at RX I Q signal 704 mVpp DC offset 1 38 V freq 67 64 kHz GSM chain functional Check Antenna switch at RX 850 Z700 56 dBm Oscilloscope check VANT1 and VANT2 at Z700 signal 0V Spectrum analyzer GSM SAW filter Z602 output 59 dBm Spectrum analyzer Check signal after inductors L603 and L602 59 dBm Check SAW filter Z602 Oscill...

Page 16: ...RX850 I Q signal waveform General Instructions for GSM1900 RX Troubleshooting Connect the phone to a PC with the module test jig Start Phoenix and establish connection to the phone Select File Scan for Product Ctrl R Select Maintenance Testing RF Controls Band GSM1900 Active Unit RX Operation Mode Continuous Rx Tx Channel 661 AGC 9 ...

Page 17: ...CCS Technical Documentation Troubleshooting Instructions RF NPM 10 Issue 1 03 2003 Nokia Corporation Confidential Page 17 The setup should now look like this ...

Page 18: ... 1960 MHz offset 67 71 kHz from generator to antenna connector Oscilloscope at RX I Q signal 416 mVpp DC offset 1 35 V freq 67 68 kHz PCS chain functional Check Antenna switch at RX 1900 Z700 58 dBm Oscilloscope check VANT1 and VANT2 at Z700 signal 0V Spectrum analyzer PCS SAW filter Z601 output 66 dBm Spectrum analyzer Check signal after inductors L611 and L601 66 dBm Check SAW filter Z601 Oscill...

Page 19: ...CCS Technical Documentation Troubleshooting Instructions RF NPM 10 Issue 1 03 2003 Nokia Corporation Confidential Page 19 Figure 11 RX1900 I Q signal waveform ...

Page 20: ...chnical Documentation Page 20 Nokia Corporation Confidential Issue 1 03 2003 Measurement Points in the Receiver Figure 12 RX measurements point at the Antenna switch Z700 Figure 13 Measurements points at the RX filters Z601 Z602 RX850 output Z700 ...

Page 21: ...CCS Technical Documentation Troubleshooting Instructions RF NPM 10 Issue 1 03 2003 Nokia Corporation Confidential Page 21 Figure 14 RX I Q Signals Base Band shielding can ...

Page 22: ...ooting Instructions RF CCS Technical Documentation Page 22 Nokia Corporation Confidential Issue 1 03 2003 Transmitter Measurement Points for the Transmitter Figure 15 TX measurement points in the PA N700 shielding can ...

Page 23: ...eneral Instructions for GSM TX Troubleshooting Apply a RF cable to the test jig s RF connector to allow the transmitted signal to act as normal The RF cable should be connected to measurement equipment with at least a 10 dB attenuator or the test equipment may be damaged Start Phoenix Service Software and Establish a connection to the phone e g FBUS or MBUS Select File Choose Product ...

Page 24: ...Data Type All 1 Your screen should look like Measure the output power of the phone it should be around 32 0 dBm Remember the loss along the end launch connector in the test jig which is around 0 3 dB Troubleshooting Chart for GSM850 Transmitter Troubleshooting the Output Power Use a high impedance probe for the spectrum analyzer measurements in the following chart Since the signal is bursted set t...

Page 25: ... 33 dBm Measure Pin at pin 7 of PA 0 dBm Measure OUT_G_TX Buffer input 1 dBm Measure BAL input to Z603 0 dBm With Scope check VTX 2 8 V discretes around No No No No No No Yes With Scope check on Ant switch Vant1 2 4 to 2 8V Vant2 0 V Yes Check R759 L702 Check Z700 Antenna switch Yes Check L709 Coupler Yes With Scope check VPCTRL_G at pin 8 of N700 See figure 18 Yes Check N700 PA Yes With Scope che...

Page 26: ...e is no significant difference between TXIP and TXIM The same is valid for TXQP and TXQM General instructions for PCS TX troubleshooting Apply an RF cable to the RF connector to allow the transmitted signal act as normal The RF cable should be connected to measurement equipment or to at least a 10 dB attenu ator otherwise the PA may be damaged Start Phoenix Service Software and Establish a connect...

Page 27: ...tion Confidential Page 27 Choose Product Excelsior Select Maintenance Testing RF Controls Band GSM1900 Active Unit TX Tx Power Level 0 Tx Data Type All 1 Your screen should look like Measure the output power of the phone it should be around 29 5 dBm Remember the loss in the test jig around 0 7 dB ...

Page 28: ... Measure Pout_DCS 29 dBm Measure Pin_PCS 2 dBm Measure OUT_D_TX Buffer input 3 dBm Measure BAL input to T600 4 dBm With Scope check VTX 2 7V discretes around No No No No No No Yes With Scope check Ant switch Vcon2_DCS 2 7 V Vcon1_GSM 2 7 V Check R759 L702 Check Z700 Ant switch Yes Check L709 Coupler Yes With Scope check VPCTRL_P See figure 21 Yes Check N700 PA Yes With Scope check VTX_B_P 2 7 V Ye...

Page 29: ...vided by two for PCS operation or by four for GSM operation inside the Mjoelner IC General Instructions for Synthesizer Troubleshooting Start the Phoenix Service Software and Select Product NPM 10 Select Maintenance Testing RF Controls Band GSM1900 Active Unit RX Operation Mode Continuous RX TX Channel 661 It is not possible to measure the output of the VCO G600 directly as this component is place...

Page 30: ...to C420 The level at this point is approx 700mVpp Frequency of this oscillator is adjusted by changing the AFC register inside the Mjoelner IC This is done via the Mjoelner serial interface Example Signal Measured at VCXO output R420 Figure 22 VCXO 26 MHz waveform VCO The VCO is generating frequencies in the range of 3296 8 MHz 3979 6 MHz when the PLL is running The output frequency from the VCO i...

Page 31: ...om Phoenix chose File Choose Product NPM 10 Mainenance Testing RF Controls GSM1900 RX continuous Ch 661 Spectrum Analyzer VCO frequency R656 3920 0 MHz No Yes PLL block functional Oscilloscope VCXO Power Supply C620 2 7 V Oscilloscope VCXO output R420 26 MHz approx 700mVpp Oscilloscope VCO Power Supply R656 2 7 V Check UEM Software Phone not in function Check UEM Software Phone not in function Spe...

Page 32: ...tructions RF CCS Technical Documentation Page 32 Nokia Corporation Confidential Issue 1 03 2003 Measurement Points for the PLL Figure 24 Measurement point for VCXO supply Figure 25 Measurement point for VCXO output VCXO Vcc C620 ...

Page 33: ...nical Documentation Troubleshooting Instructions RF NPM 10 Issue 1 03 2003 Nokia Corporation Confidential Page 33 Measurement Points at the PLL VCO Figure 26 Measurement points for PLL PLL Vcc C634 PLL Vcc C665 ...

Page 34: ...491 2 188 836 2 881 2 3344 8 3524 8 228 844 2 889 2 3376 8 3556 8 147 828 873 3312 3492 189 836 4 881 4 3345 6 3525 6 229 844 4 889 4 3377 6 3557 6 148 828 2 873 2 3312 8 3492 8 190 836 6 881 6 3346 4 3526 4 230 844 6 889 6 3378 4 3558 4 149 828 4 873 4 3313 6 3493 6 191 836 8 881 8 3347 2 3527 2 231 844 8 889 8 3379 2 3559 2 150 828 6 873 6 3314 4 3494 4 192 837 882 3348 3528 232 845 890 3380 356...

Page 35: ... 734 1894 6 1974 6 3789 2 3949 2 535 1854 8 1934 8 3709 6 3869 6 635 1874 8 1954 8 3749 6 3909 6 735 1894 8 1974 8 3789 6 3949 6 536 1855 1935 3710 3870 636 1875 1955 3750 3910 736 1895 1975 3790 3950 537 1855 2 1935 2 3710 4 3870 4 637 1875 2 1955 2 3750 4 3910 4 737 1895 2 1975 2 3790 4 3950 4 538 1855 4 1935 4 3710 8 3870 8 638 1875 4 1955 4 3750 8 3910 8 738 1895 4 1975 4 3790 8 3950 8 539 185...

Page 36: ...1 1904 1984 3808 3968 582 1864 2 1944 2 3728 4 3888 4 682 1884 2 1964 2 3768 4 3928 4 782 1904 2 1984 2 3808 4 3968 4 583 1864 4 1944 4 3728 8 3888 8 683 1884 4 1964 4 3768 8 3928 8 783 1904 4 1984 4 3808 8 3968 8 584 1864 6 1944 6 3729 2 3889 2 684 1884 6 1964 6 3769 2 3929 2 784 1904 6 1984 6 3809 2 3969 2 585 1864 8 1944 8 3729 6 3889 6 685 1884 8 1964 8 3769 6 3929 6 785 1904 8 1984 8 3809 6 3...

Page 37: ... tuning procedures Always look at what is shown in the windows regarding these issues and act accordingly To vary a selected parameter you can use and key or in some cases directly type the new value and steps the value for every press Repeat function seems not to work In I Q you can use the side arrows RX Calibration Select Maintenance Tuning RX Calibration Select Band GSM850 Note that GSM850 mus...

Page 38: ...emory are shown Set sig gen settings to the freq and amplitude specified in the popup window Select OK 850 band will be calibrated and automatically stored in PM Phoenix will then prompt for 1900MHz calibration while displaying the current values in PM Again set up sig gen settings as shown and select OK New RSSI values will be calculated and stored in PM RX cal is now complete ...

Page 39: ...poration Confidential Page 39 RX Channel Select Filter Select Maintenance Tuning Rx Channel Select Filter Calibration Next select to load values from the phone or not Press AutoTune Press Stop and you can select to save values to the phone or not Note This calibration requires no input signal ...

Page 40: ...ter Response Select Maintenance Tuning Rx Band Filter Response Compensation Press Start Read from PM area and you can select to load values from the phone or not Press Manual Tuning Set the Signal generator according to the pop up windows When finished press Stop Write to PM area and you can select to save values to the phone or not ...

Page 41: ... frequency list option you can with advantage use Auto Tuning Dwell should be around 10 ms Tx Tuning Phoenix menu Select Maintenance Tuning Tx Power Level Tuning Settings and considerations for tuning with a spectrum analyzer A DC block and at least 10 dB attenuator should be used on the RF input port to protect the spectrum analyzer The burst power should be measured so a span of 0 Hertz is used ...

Page 42: ...ut levels The reference level must be reduced to say 0 dB level when tuning the base level Trigger Video Set the level to 0 dbm This must be lowered when you are setting the base level Base level target output power of 30 dBm If you don t lower the video trig ger level to below 30 dBm when tuning the base level the spectrum analyzer will not be triggered when you are tuning the base level Center F...

Page 43: ...ation 1 0 or random in Tx Data Type Select random if a GSM tester is used Then it can be synchronised to the burst Select Tx PA Mode High Note that Low PA Mode tuning is not to be used First power tuning should be setting base level to 30dBm Tune the highlighted values in BOLD to the target value highlighted in blue Use aver age burst power also Note PL5 target value is 32dBm not 32 5dBm After tun...

Page 44: ...els are tuned select OK Phoenix will then calculate the coefficients for the remaining power levels and save them to permanent memory Tx power level tuning is complete TX I Q Tuning Phoenix Menu Select Maintenance Tuning Tx IQ tuning Settings for spectrum analyzer for I Q tuning Same center frequencies are used for GSM 850 Ch190 836 6 MHz and 1900 Ch661 1880 MHz as in Tx output power tuning Span 2...

Page 45: ...Hz Sweeptime 5 seconds RF attenuation 20 dB Reference level 30 dBm Trigger free run Select where to get values Normally select Load From Product Push Start soft key Tune I and Q DC offset values to reduce the carrier frequency to a minimum Use Side arrows or Carrier must be at least 30 dBc Typically carrier supression is better than 40 dBc ...

Page 46: ...ration Confidential Issue 1 03 2003 Tune Amplitude and phase difference to reduce the lowest sideband frequency The side band must be reduced at least 35 dBc Typically sideband supression is better than 40 dBc Check the IQ tuning values meet the specifications for both 1 and 0 data types ...

Page 47: ... Remember to check the box Save to Product if you want to save the tuning values to the phone Push Stop softkey This ends tuning and saves the values to the phone if you have selected the save to product box Same procedure is used for PCS1900 as for GSM Channel will be 661 as pictured below with some typical tuning values ...

Page 48: ...ne at other channels than the default then you must select it first in RF control and then start the tuning Call Testing If all tunings are done and the phone TX and RX is working a call is the ultimate test of the phone Set the communications tester to manual test Switch the phone to normal if it was in local mode Remember to have a test simcard in the phone After the phone has registered to the ...

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