User's Manual

DE910 Series Hardware User Guide
1vv0300951 Rev.9 – 2015-05-11
Reproduction forbidden without written authorization from Telit Communications S.p.A. - All Rights
Reserved. Page 44 of 77
6.3.4. GNSS Antenna – PCB Line Guidelines
 Ensure that the antenna line impedance is 50ohm.
 Keep line on the PCB as short as possible to reduce the loss.
 Antenna line must have uniform characteristics, constant cross section, avoid meanders
and abrupt curves.
 Keep one layer of the PCB used only for the Ground plane; if possible.
 Surround (on the sides, over and under) the antenna line on PCB with Ground. Avoid
having other signal tracks directly facing the antenna line track.
 The Ground around the antenna line on PCB has to be strictly connected to the main
Ground plane by placing vias once per 2mm at least.
 Place EM noisy devices as far as possible from DE910 antenna line.
 Keep the antenna line far away from the DE910 power supply lines.
 If EM noisy devices are around the PCB hosting the DE910, such as fast switching ICs,
take care of shielding of antenna line by burying it inside the layers of PCB and
surround it with Ground planes; or shield it with a metal frame cover.
 If you do not have EM noisy devices around the PCB of DE910, use a strip line on the
superficial copper layer for the antenna line. The line attenuation will be lower than a
buried one.
6.3.5. GNSS Antenna – Installation Guidelines
 The DE910, due to its sensitivity characteristics, is capable of performing a fix inside
buildings. However, the sensitivity could be affected by the building characteristics i.e.
shielding.
 The Antenna must not be co-located or operating in conjunction with any other antenna
or transmitter.
 Antenna shall not be installed inside metal cases.
 Antenna shall be installed also according antenna manufacture instructions.
WARNING:
Consider a mechanical design and a low-capacitance ESD protection device to protect DE910
or customer specific requirements from ESD event to GPS port (R9).