Sony Ericsson GR64 Manuel D’Utilisation

Page de 91
 
LZT 123 1834 
79
 
 
 
 
 
It is recommended that you use a cable with a maximum resistance of 
5  milliohm for the ground connection. 
AREFand GND are connected at a single point inside the wireless 
modem.  They must not be joined together in your application. 
7.4.2.3 Audio 
Use a coupling capacitor in AUXI line if the application does not use the wireless 
modem’s bias voltage. See also Figure 5.9-1  Microphone connections to the wireless 
modem, page 52. 
7.4.2.4 Software Upgrade 
There are two ways of updating the firmware in the GR64.  There is a web-based tool 
that can access a Sony Ericsson server from where SW can be downloaded. There also 
is an Updater, which is a local application that downloads an image provided by 
SEMC. 
7.5  Antenna 
7.5.1  General 
The antenna is the component in the users system that maintains the radio link 
between the network and the wireless modem. Since the antenna transmits and 
receives electromagnetic energy, its efficient function will depend on: 
• 
Type of antenna (for example, circular or directional) 
• 
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, users should contact their local antenna manufacturer for additional 
information concerning antenna type, cables, connectors, antenna placement, and 
the surrounding area. Users should also determine whether the antenna needs to be 
grounded or not.  Usually, a local antenna manufacturer should be able to design a 
special antenna suitable for the integrators application and environment. 
7.5.2  Antenna Type 
Users should ensure that they choose the right type of antenna for the wireless 
modem.   
NOTE