Nokia Customer Care 2255 (RM-97) Mobile Terminal Antenna Description and Troubleshooting ISSUE 1 10/2005 Company Confidential ©2005 Nokia Corporation
255 (RM-97) Antenna Description and Troubleshooting Contents Page Introduction ..................................................................................................................................................... 3 Stub Antenna ................................................................................................................................................ 3 Failures and Corrective Measures ....................................................................................
2255 (RM-97) Antenna Description and Troubleshooting Nokia Customer Care Introduction This troubleshooting guide addresses potential failures that affect antenna performance of the 2255, and discusses methods for correction of these failures. Stub Antenna The 2255 uses a single band stub antenna for CDMA CELL band. The antenna radiator is a flex meander that is wrapped around a plastic connector and overmolded.
2255 (RM-97) Antenna Description and Troubleshooting Failures and Corrective Measures Installing the stub antenna Figure 2 shows the assembly of the stub antenna into the D-cover. Figure 2: Installing a stub antenna If no stub antenna is installed, the antenna gain will be degraded by more than 25 dB. The stub has a hook on the antenna anchor which locks the antenna into the D-cover when installed. See Figure 3.
Nokia Customer Care 2255 (RM-97) Antenna Description and Troubleshooting Whip/Stub antenna Figure 4: Antenna locked into D-cover and plastic loop in C-cover Uninstalling the stub antenna During disassembly of the mobile terminal, the antenna needs to be uninstalled first. To uninstall an antenna, a special extraction tool is needed. The antenna should never be extracted by force as the antenna and/or the D/C-covers may brake or be damaged.
2255 (RM-97) Antenna Description and Troubleshooting 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 Figure 2. • 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. • If the RF feed pin of the stub antenna does not touch the PWB, the antenna gain will degrade by more than 25 dB.
