u-blox NORA-W2 Series, Hardware Integration Manual

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NORA-W2 series - Hardware integration manual
UBX-22005177 - R01 Design-in Page 19 of 61
C1 – Public
• Proper placement of the antenna and its surroundings is also critical for antenna performance.
Avoid placing the antenna close to conductive or RF-absorbing parts such as metal objects, ferrite
sheets and so on as they may absorb part of the radiated power or shift the resonant frequency of
the antenna or affect the antenna radiation pattern.
• It is highly recommended to strictly follow the detailed and specific guidelines provided by the
antenna manufacturer regarding correct installation and deployment of the antenna system,
including PCB layout and matching circuitry.
• Further to the custom PCB and product restrictions, antennas may require tuning/matching to
comply with all the applicable required certification schemes. It is recommended that you plan
measurement and validation activities with the antenna manufacturer before releasing the end-
product to manufacturing.
• RF section may be affected by noise sources like hi-speed digital buses. Avoid placing the antenna
close to buses such as DDR or consider taking specific countermeasures like metal shields or
ferrite sheets to reduce the interference.
⚠
Take care of the interaction between co-located RF systems like LTE sidebands on 2.4 GHz band.
Transmitted power may interact or disturb the performance of NORA-W2 series modules.
3.2.4 NORA-W256AWS
If a plastic enclosure is used, it is possible to use NORA-W256AWS with the embedded antenna. To
reach optimum operating performance, follow the instructions in this section.
3.2.4.1 Internal or PCB trace antenna
• The module shall be placed in the center of an edge of the host PCB.
• A large ground plane on the host PCB is a prerequisite for good antenna performance. It is
recommended to have the ground plane extending at least 10 mm on the three non-edge sides of
the module. See also
Figure 6 .
• The host PCB shall include a full GND plane underneath the entire module, with a ground cut out
under the PCB trace antenna according to the description in
Figure 7 .
•
The NORA-W256AWS has six extra GND pads under the antenna that need to be connected for a
good antenna performance. Detailed measurements of the footprint including this extra GND
pads can be found in the NORA-W2 series data sheet
[2] .
• High / large parts including metal shall not be placed closer than 10 mm to the module’s antenna.
• At least 10 mm clearance between the antenna and the casing is recommended. If the clearance
is less than 10 mm, the antenna performance can be adversely affected.
• The module shall be placed such that the antenna faces outwards from the product and is not
obstructed by any external items in close vicinity of the products intended use case.