User's Manual

CE910 Family Hardware User Guide

1vv0301010 Rev.11 – 2015-10-27

Page 39 of 75

must not be co-located or operating in conjunction with any other antenna 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 CE910

module. Antennas used for this OEM module must not exceed 5dBi gain for mobile and fixed

operating configurations.

6.2. CDMA antenna – PCB line Guidelines

 Make sure that the transmission line’s characteristic impedance is 50ohm.

 Keep line on the PCB as short as possible since the antenna line loss shall be less than around

0.3dB.

 Line geometry should have uniform characteristics, constant cross section, avoid meanders and

abrupt curves.

 Any kind of suitable geometry/structure can be used for implementing the printed transmission

line afferent the antenna.

 If a Ground plane is required in line geometry, that plane has to 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.

 It is wise to surround (on both sides) the PCB transmission line with Ground. Avoid having

other signal tracks facing 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 PCB has to 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 line track.

 Place EM noisy devices as far as possible from CE910 antenna line.

 Keep the antenna line far away from the CE910 power supply lines.

 If EM noisy devices are present on the PCB hosting the CE910, such as fast switching ICs, take

care of shielding them with a metal frame cover.

 If EM noisy devices are not present around the line use of geometries like Micro strip or

Grounded Coplanar Waveguide are preferred since they typically ensure less attenuation when

compared to a Strip line having same length.

6.3. CDMA Antenna installation Guidelines

 Install the antenna in a place covered by the CDMA signal.

 If the device antenna in the application is located greater then 20cm from the human body and

there are no co-located transmitters then the Telit FCC/IC approvals can be re-used by the end

product.

 Antenna shall not be installed inside metal cases.

 Antenna shall be installed also according to antenna manufacture instructions.

WARNING:

Consider a mechanical design and a low-capacitance ESD protection device to protect CE910 or

customer specific requirements from ESD event to Antenna port (K1).