Nokia 2255 Manual Do Serviço
2255 (RM-97)
Antenna Description and Troubleshooting
Page 6
©2005 Nokia Corporation Company Confidential
ISSUE 1 10/2005
Damaged RF Feed Pin
The stub antenna has a spring clip feed contact that should properly touch the PWB.
Positioning of this pin is shown in
Positioning of this pin is shown in
• If the RF feed pin is broken or bent the pin will not touch the PWB and the stub
antenna must be replaced. If the spring for the RF feed pin damaged, replace the
stub antenna.
stub antenna.
• If the RF feed pin of the stub antenna does not touch the PWB, the antenna gain
will degrade by more than 25 dB.
Obstructed RF feed pad or missing matching circuit
If the RF feed pin is obstructed, removed or covered, the RF pin will not touch the PWB
and then the antenna performance will degrade.
and then the antenna performance will degrade.
• If corrosion is present or the pad is missing, replace the PWB and the mobile
terminal.
• If either pad is obstructed or covered, clean and/or clear the pad.
The antenna matching circuit is positioned next to the RF feed pad. If the matching
circuit is improperly installed or any of the components are missing, the antenna gain
will be degraded by about 25dB.
circuit is improperly installed or any of the components are missing, the antenna gain
will be degraded by about 25dB.
Figure 6: PWB layout of RF feed pad and matching circuit
Antenna pad
Matching circuit
3.9pF
4.7nH
4.7nH