Sony Ericsson GM48, GM47 manual Antenna

GM47/GM48 INTEGRATOR’S MANUAL

Grounds

A ground connection is provided at the mounting hole next to the RF connector on the module (see Figure 2.1, page 41). Connect this ground point to the DGND pins of the module by the shortest, low-impedance path possible. The purpose of this connection is to allow any ESD picked up by the antenna to bypass the module’s internal ground path.

Note! It is recommended that you use a cable with a maximum resistance of 5mΩ for the ground connection.

Note! AGND and DGND are connected at a star point inside the module. They must not be joined together in your application.

Audio

Use a coupling capacitor in ATMS line if the application does not use the module’s bias voltage. See also “Figure 2.3 Microphone connections to the module”, page 50.

Software Upgrade

To upgrade the software, the system connector must be accessible in your application. The pins SERVICE, TD, RD and the power signals are used for this purpose. Please contact customer support for more details.

4.3 Antenna

4.3.1 General

The antenna is the component in your system that maintains the radio link between the network and the module. Since the antenna transmits and receives electromagnetic energy, its efficient function will depend on:

•the type of antenna (for example, circular or directional);

•the placement of the antenna;

•communication disturbances in the vicinity in which the antenna operates.

In the sections below, issues concerning antenna type, antenna placement, antenna cable, and possible communication disturbances are addressed.

In any event, you should contact your local antenna manufacturer for additional information concerning antenna type, cables, connectors, antenna placement, and the surrounding area. You should also

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