Figure 31. Location of large components
6.8.4. Common Problems of Internal Antenna Overall Design
Factors that would affect transmitting performance
•
As the internal antenna is sensitive to the nearby medium, so the design of shell is
closely related to antenna performance.
•
Poor speaker layout will affect antenna performance.
•
Poor battery layout will affect antenna performance.
Factors that would affect receiving performance
•
If both the conductive performance of module and the radiated power of antenna
meet requirement, then low sensitivity may be caused by main board design issue.
•
Poor coupling sensitivity is caused by poor circuit design of LCD, LDO, and DC/DC.
•
Device receiving performance is affected by VCXO or TXVCO harmonic of 19.2MHZ,
26MHZ, and 38.4MHZ systems.
•
Poor coupling sensitivity is caused by SIM card clock.
•
Poor FPC layout affects the receiving performance of the device.
Factors that would affect electromagnetic compatibility (EMC)
•
Poor FPC layout affects EMC performance of the device.
6. Radio Frequency
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