User Guide

ME910G1 HW Design Guide
1VV0301593 Rev.7 Page 58 of 98 2021-02-02
PCB Design guidelines
When using the ME910G1, since there's no antenna connector on the module, the antenna
must be connected to the ME910G1 antenna pad (K1) by means of a transmission line
implemented on the PCB.
This transmission line shall fulfil the following requirements:
Item
Value
Characteristic Impedance
50 ohm (+-10%)
Max Attenuation
0,3 dB
Coupling
Coupling with other signals shall be avoided
Ground Plane
Cold End (Ground Plane) of antenna shall be equipotential to the ME910G1
ground pins
Table 27: ME910G1 Antenna pad requirements
The transmission line should be designed according to the following guidelines:
• make sure that the transmission line’s characteristic impedance is 50 ohm;
• keep line on the PCB as short as possible, since the antenna line loss shall be less
than about 0,3 dB;
• line geometry should have uniform characteristics, constant cross section, avoid
meanders and abrupt curves;
• any kind of suitable geometry / structure (Microstrip, Stripline, Coplanar,
Grounded Coplanar Waveguide...) can be used to implement the printed
transmission line afferent the antenna;
• if a Ground plane is required in line geometry, that plane shall be continuous and
sufficiently extended, so that 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;
• it is advisable to surround (on both sides) the PCB transmission line with Ground,
avoiding that other signal tracks face directly the antenna line track.
• avoid crossing any un-shielded transmission line footprint with other signal tracks
on different layers;
• the ground surrounding the antenna line on PCB shall be strictly connected to the
main Ground Plane by means of via holes (once per 2mm at least), placed close to
the ground edges facing the line track;