User's Manual

Note d‘étude / Technical document :
URD1– OTL 5696.1– 003 / 72361 Edition 02
HILO 3G Application Note
17 January 2011 - Page 31 / 38
6.1.3 Antenna Notice
Antenna for HiLo3G should be resonated in the operating bands (GSM 850, 900, 1800, 1900 + UMTS band 1, 2, 5,8)
depending on HiLo3G reference.
Pay attention to the RF-impedance of the HiLo3G (50Ω)
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 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 will have a good ground
contact with the customer board.
Figure 31: Ground HiLo3G to customer board