Antenna Cabling; Platform Noise Mitigation; Antenna Material Choices; Zigbee System Integration Considerations - Intel Quark SoC X1000 Design Manual

22.2.7

Antenna Cabling

The antenna cable is a lossy structure and hence needs to be as short as possible.
Design choices can help reduce the cable length to the absolute minimum
achievable.Studies have shown that acceptable performance metrics (loss/VSWR) can
been achieved with1.37mm diameter/double shielded cables.
22.2.8

Platform Noise Mitigation

Straddle mounted/Mid-mounted connectors help in reducing the EMI from the platform
by reducing the lengths of connector pins which act as radiating elements. This is an
additional benefit over and above the z-height saving that straddle-mounted
connectors provide.
EMI sources on the platform (eg. right-angle connectors, large inductors etc.) will need
to be identified by probing and may require to be shielded to cut down on EMI and
improve antenna performance.
System designers must be aware of noise impact from several high speed digital
interfaces there is the possibility of leakage from the connector.
22.2.9

Antenna Material Choices

• FPC (Flex Printed Circuit): This methodology has the advantage of printing
antennas on flexible strips of film or plastic. The antennas will be extremely thin
and can be accommodated easily into narrow spaces and can also be bent around
corners. Prototyping and testing is also easier than other options. However care
should be taken to ensure that the antenna is assembled in the exact same shape
and orientation that it was validated in.
• Stamped Metal: Stamped metal antennas are low cost but will require an initial
tooling cost, which may increase with the number of prototypes in the process of
fine-tuning the antenna.
• LDS (Laser Direct Structuring): LDS is a process of antenna design and
manufacturing that allows for low-cost, rapid prototyping. With the LDS technique
the antenna can be etched onto almost any surface, thus providing many options
for antenna integration.
• Chip Antennas on high Dielectric material: Another technique involves utilizing
antennas built on high dielectric materials such as ceramic chip antennas. While the
over the air coupling mechanism in such antennas is identical to antenna built with
air core or low dielectric, the surface waves in the dielectric are tightly confined to
the respective antennas providing enhancement in port to port antenna isolation.
Chip antennas have the added benefit of smaller size, though there could be trade-
offs associated with providing adequate keep out zones to maximize performance.
22.3

ZigBee System Integration Considerations

SoC based platforms supporting ZigBee (802.15.4)
22.3.1

ZigBee Antenna Placement

Similarly to module based WiFi solutions Zigbee solutions shall be based on daughter
card/modules. The antenna placement guideline for such a module should be extracted
from the relevant Zigbee device datasheet.
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Intel Quark™ SoC X1000
PDG
170
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Intel Quark™ SoC X1000—Wireless Modules and Antenna Design Guidelines
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June 2014
Order Number: 330258-002US