User's Manual

HiLo3G-850 User Manual
04 March 2011 - Page 30 / 36
Use low loss antenna cable (max. 0.5dB).
To avoid interference choose an antenna type radiating off the device.
Circular polarized antennas are preferred.
Verify the operation of the antenna by measurement of the total radiated power.
Avoid placing a transmit antenna close to sensitive areas (danger from interference).
Apply EMC-design rules and follow shielding concepts.
 Separate of EMC-sensitive and high-emission areas.
6.2 Ground Link Area
Good ground GND contact between the module and customer‘s board is required to have the best radio performances
(spurious, sensitivity…)
 All HiLo3G-850 GND pins must be connected to the GND of the customer‘s board.
 Solder the three pads of the shielding on the ground pads of customer board, then the HiLo3G-850 will have a good
ground contact with the customer board.
Figure 31: Ground HiLo3G-850 to customer board
6.3 Layout
Isolate RF line and antenna from other bus or signals
No signals on 50 ohms area and if that is not possible, add ground shielding using different layers.
Do not add any ground layer under the antenna contact area.