DE910 Series Hardware User Guide
1vv0300951 Rev.9 – 2015-05-11
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Reserved. Page 36 of 77
This transmission line shall fulfill the following requirements:
Antenna Line on PCB Requirements
Characteristic Impedance
50Ohm
Max Attenuation
0.3dB
Coupling with other signals shall be avoided
Cold End (Ground Plane) of antenna shall be equipotential to the DE910 ground pads
Furthermore if the device is developed for the US and/or Canada market, it must comply with
the 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
persons and 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 DE910 module. Antennas used for this OEM module
must not exceed 5dBi gain for mobile and fixed operating configurations.
6.1.1.
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 ( Microstrip, Stripline, Coplanar, Grounded
Coplanar Waveguide … ) 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) of 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 DE910 antenna line.
Keep the antenna line far away from the DE910 power supply lines.
