LE910Cx HW User Guide
1VV0301298 Rev. 33
Page 61 of 128
2021-06-29
Not Subject to NDA
Furthermore, if the device is developed for the US and/or Canadian market, it must
comply with FCC and/or IC approval requirements:
This device is to be used only for mobile and fixed application. The antenna(s) used for
this transmitter must be installed to provide a separation distance of at least 20 cm from
all people and must not be co-located or operating in conjunction with any other antennas
or transmitter. End-Users must be provided with transmitter operation conditions for
satisfying RF exposure compliance. OEM integrators must ensure that the end user has
no manual instructions to remove or install the LE910Cx module. Antennas used for this
OEM module must not exceed 3dBi gain for mobile and fixed operating configurations.
GSM/WCDMA/TD-SCDMA/LTE Antenna – PCB Line
Guidelines
•
Make sure that the transmission line’s characteristic impedance is 50 Ohm.
•
Keep the line on the PCB as short as possible since the antenna line loss should
be less than around 0.3 dB.
•
Line geometry should have uniform characteristics, constant cross sections, and
avoid meanders and abrupt curves.
•
Any suitable geometry/structure can be used to implement the printed
transmission line affecting the antenna.
•
If a ground plane is required in the line geometry, this plane must be continuous
and sufficiently extended so the geometry can be as similar as possible to the
related canonical model.
•
Keep, if possible, at least one layer of the PCB used only for the Ground plane. If
possible, use this layer as reference Ground plane for the transmission line.
•
Surround the PCB transmission line with ground (on both sides). Avoid that other
signal tracks face directly the antenna line track.
•
Avoid crossing any un-shielded transmission line footprint with other tracks on
different layers.
•
The ground surrounding the antenna line on the PCB must be strictly connected
to the main Ground plane by means of via-holes (once per 2 mm at least) placed
close to the ground edges facing the line track.
•
Place EM-noisy devices as far as possible from LE910Cx antenna line.
•
Keep the antenna line far away from the LE910Cx power supply lines.