User's Manual

Note d‘étude / Technical document :
URD1– OTL 5696.1– 003 / 72361 Edition 02
HILO 3G Application Note
17 January 2011 - Page 30 / 38
6. Radio Integration
HiLo3G incorporates the technology for RF transceiver that converts received signals directly from RF-to-baseband and
transmits signals directly from baseband-to-RF (known as direct conversion or zero intermediate frequency (ZIF)
processing). This technique eliminates the need for large IF surface acoustic wave (SAW) filters and supporting IF and LO
circuits.
6.1 Antenna Connection
HiLo3G provides two methods to connect an antenna, one is spring contact and the other is UFL RF connector.
Definition of the reference antenna connector:
• Strictly 50 Ohms matched impedance PCB tracks
• Straight PCB tracks
Antenna gain:
• Radiation pattern: depending on antenna position and size of the device
• Gain averaged in space in all frequencies: > -3dBi
• Maximum VSWR: < 1.5:1 with 50 Ohms reference impedance
In order to get the best sensitivity and output power, it is recommended to implement a matching circuit between the
module and the antenna:
Figure 29: Antenna connection reference
6.1.1 Antenna Connector
A 50-Ohm RF connector on the HiLo3G PCB is available for antenna (RF cable) connection.
Reference
HIROSE U.FL-R-SMT-1 (10)
6.1.2 Spring Contact
50 Ω line matching
Recommends to solder the spring contact on the whole surface instead of only 2 points
Figure 30: Spring contact