User's Manual

page 45/64
Note d’étude / Technical document : URD1– OTL
5665.3 – 003 / 72238 Edition 01
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7.3 LAYOUT
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Isolate RF line and antenna from others bus or signals
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No signals on 50 ohms area and if that is not possible, add ground shielding using different layers.
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Do not add any ground layer under the antenna contact area.
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Varnish must be present on all the grey area of the customer's board (expect solder pads) to isolate
HiLoNC V2 module from the customer’s board
Figure 45: Mandatory area for varnish
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This recommendation is due to the presence of signals (below varnish) and fiducials and golden tests
points and UL PCB marking (without varnish area in Yellow on the picture above) on the back side of the
module. If customer’s board has layout or via without varnish below the HiLoNC V2 module, short-circuits
could occur between them.
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Free CAD software can be used to compute the stack-up parameter that leads to a compliant 50Ω RF
track.
Connection between two RF tracks of different widths or of a FR line with a smaller pad component must be
smoothed to keep a correct RF adaptation.
Figure 46: Connection of RF lines with different width
Not correct
conn
ection
Correct
co
nnection