User Manual

Confidential and Proprietary SEQUANS Communications 11
4. HW integration guidelines
RF connections
When attaching antennas to the module:
Note: To disconnect the antenna, make sure you use the specific RF connector to prevent damage to the module or
coaxial cable assembly.
•Use the specific RF connector to attach antennas to the module’s connection points.
•Match coaxial connections between the module and the antenna to 50 Ohm.
•Minimize RF cable losses to the antenna; the recommended maximum cable loss for antenna cabling is
0.5 dB.
•To ensure best thermal performance, if possible use the mounting holes to attach (ground) the device to
the main PCB ground or a metal chassis.
Note: If the antenna connection is shorted or open, the modem will not sustain permanent damage.
Shielding
The module is fully shielded to protect against EMI and must not be removed.
Antenna and cabling
When selecting the antenna and cable, it is critical to RF performance to match antenna gain and cable loss.
Choosing the correct antenna and cabling
When matching antennas and cabling:
•The antenna (and associated circuitry) should have a nominal impedance of 50 Ohms with a return loss
of better than 10 dB across each frequency band of operation.
•The system gain value affects both radiated power and regulatory (FCC, IC, etc.) test results.
Designing custom antennas
Consider the following points when designing custom antennas
•A skilled RF engineer should do the development to ensure that the RF performance is maintained.
Determining the antenna’s location
When deciding where to put the antennas: