Antenna Interface - Fibocom G610 Hardware User Manual

6 Antenna Interface

The RF interface of the G610 Module has an impedance of 50Ω. The module is capable of
sustaining a total mismatch at the antenna connector or pad without any damage, even when
transmitting at maximum RF power.
The external antenna must be matched properly to achieve best performance regarding radiated
power, DC-power consumption, modulation accuracy and harmonic suppression. Antenna matching
networks are not included on the G610 Module PCB and should be placed in the host application.
Regarding the return loss, the Module provides the following values in the active band:
State of Module
Receive
Transmit
The connection of the antenna or other equipment must be de coupled from DC voltage. This is
necessary because the antenna connector is DC coupled to ground via an inductor for ESD protection.
6.1 Antenna Installation
The G610 Module has no antenna connector, so antenna will be installed on the customer
application board.
6.2 Antenna Subsystem
The antenna sub-system and its design is a major part of the final product integration. Special
attention and care should be taken in adhering to the following guidelines.
6.2.1 Antenna Specifications
Choice of the antenna cable (type, length, performance, RF loss, etc) and antenna connector (type
+ losses) can have a major impact on the success of the design.
6.2.2 Cable Loss
All cables have RF losses. Minimizing the length of the cable between the antenna and the RF
connectors on the module will help obtain superior performance. High Quality/Low loss co-axial cables
should be used to connect the antenna to the RF connectors. Contact the antenna vendor for the
G610 GPRS Module Hardware User Manual
Table 6-1 Return Loss in the Active Band
Return Loss of
Module
≥ 8dB
not applicable
Recommended Return
Loss of
Application
≥ 12dB
≥ 12dB
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