Multi-Tech Systems 92U03G23720 ユーザーズマニュアル

Chapter 6 – Application Considerations

Wireless ModemModule MTMMC-G-F1 and MTMMC-G-F2 Developer’s Guide

    

·  Ground plane: MultiTech recommends having a common ground plane for analog, digital and RF grounds.

·  Length of the SIM interface lines (15 cm maximum)

·  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 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 GSM performances such as sensitivity and emitted power.

The antenna should be isolated as much as possible from the digital circuitry including the interface signals.

MultiTech 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.

The ModemModule firmware is stored in flash memory, and it can easily be upgraded. Contact the factory for
details.

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.