User's Manual
Table Of Contents
CDMA and GSM / UMTS Mini Card Hardware Integration Guide
24 Proprietary and Confidential 2130114
In the event of a discrepancy in values between this guide and the Product Specification Document (PSD), the PSD takes precedence.
Theseverityofthisinterferencedependsontheclosenessof
theotherantennastothemodule’santenna.Todetermine
suitablelocationsforeachwirelessdevice’santenna,
thoroughlyevaluateyourhostdevice’sdesign.
Device-generated RF
Note: The module can cause
interference with other devices
such as hearing aids and on-
board speakers.
Wireless devices such as the
Mini Card transmit in bursts
(pulse transients) for set
durations (RF burst frequencies).
Hearing aids and speakers
convert these burst frequencies
into audible frequencies,
resulting in audible noise.
AllelectroniccomputingdevicesgenerateRFinterferencethat
cannegativelyaffectthereceivesensitivityofthemodule.
Theproximityofhostelectronicstotheantennainwireless
devicescancontributetodecreasedRxperformance.Compo‐
nentsthataremostlikelytocausethisinclude:
• Microprocessorandmemory
• Displaypanelanddisplaydrivers
• Switching‐modepowersupplies
Theseandotherhigh‐speeddevices(inparticular,the
processor)candecreaseRxperformancebecausetheyrunat
frequenciesoftensofMHz.Therapidriseandfallofthese
clocksignalsgenerateshigher‐orderharmonicsthatoftenfall
withintheoperatingfrequencybandofthemodule,affecting
themodule’sreceive
sensitivity.
Example
Onasub‐systemrunningat40MHz,the22ndharmonicfalls
at880MHz,whichiswithinthecellularreceivefrequency
band.
Note: In practice, there are usually numerous interfering frequencies
and harmonics. The net effect can be a series of desensitized receive
channels.