Test Equipment; Path Of The Received Signal - Nokia RH-3 Series Troubleshooting - Gps

RH-3
Troubleshooting — GPS
Reference (See Figure 9).
Please note that before changing ASICs or filters, soldering and missing components
must be checked visually. There are no parameters in GPS RF, which should be tuned
externally. Accurate signal levels are not shown in the flowcharts below because of the
figures apply with specific measurement probes. It is useful to compare the results
against reference phones.

Test Equipment

1 Signal generator up to 2 GHz
2 Oscilloscope with 10:1 passive probe
3 High Frequency Probe for Spectrum Analyzer (Please note that the signal levels
mentioned in the RX troubleshooting have been measured with an active probe.)
4 Spectrum analyzer up to 6.7 GHz
5 PC with Phoenix SW and GPS option

Path of the Received Signal

1575.42 MHz
LNA
BPF SAW
16.368 MHz
TCXO
Page 14
4.092MHz
Image Reject
Mixer
LO=1571.328 MHz
÷ 2
Loop VCO
Filter Tank
÷ 2
÷ 8
÷12
fcomp=16.368MHz
Ph ase
Det
Oscillator
Figure 8: GPS RF Functional Diagram
Nokia Corporation
CCS Technical Documentation
AGC
4 Bit
ADC
IF out Tes t
Points
LO/8 Test Point
196.416 MHz
DATA
Pr ogramming
CLOCK
Interface
ENABLE
Confidential
ADCout
4
IFout
GPS Clock
LO/8 Test
SPI
Issue 1 06/2003