User's Manual

Chapter 6 – Application Considerations
Wireless ModemModule MTMMC-C Developer's Guide 18
Chapter 6 – Application Considerations
General Guidelines for the Use of the ModemModule
Hardware and RF
· Ground plane: Multi-Tech recommends having a common ground plane for analog, digital and RF grounds.
· Bias of the Microphone inputs must be properly adjusted when using audio connectors (mic + speaker) 1.
· EMC protection on audio input/output (filters against 900 MHz)
· ESD protection on serial link
· Possible spurious emission radiated by the application to the RF receiver in the receiver band
The Antenna
The antenna sub-system and integration in the application is a major issue. It is a major issue in the choice of the
antenna cable (type, length, performances, thermal resistance, etc.)
These elements could affect CDMA performances such as sensitivity and emitted power.
The antenna should be isolated as much as possible from the digital circuitry including the interface signals.
Multi-Tech recommends shielding the terminal. On terminals including the antenna, a poor shielding could
dramatically affect the sensitivity of the terminal. Subsequently, the power emitted through the antenna could
affect the application.
Firmware Upgrade
The ModemModule firmware is stored in flash memory, and it can easily be upgraded. Contact the factory for
details.
Initial Configuration Using Mobile PhoneTools
For Initial configuration of your wireless device, Multi-Tech offers a Windows-based mobile PhoneTools
application.
To load Mobile PhoneTools, click on the Mobile PhoneTools icon on the system CD and follow the on-screen
prompts.