MAX-7 / NEO-7 - Hardware Integration Manual
UBX-13003704
-
R09
Production Information
Design
Page
20 of 52
3.3.2
Placement
A very important factor in achieving maximum performance is the placement of the receiver on the PCB. The
connection to the antenna must be as short as possible to avoid jamming into the very sensitive RF section.
Make sure that the RF critical circuits are separated from any other digital circuits on the system board. To
achieve this, position the module’s digital part towards the digital section on the system PCB. Exercise care if
placing the receiver in proximity to heat emitting circuitry. The RF part of the receiver is very sensitive to
temperature and sudden changes can have an adverse impact on performance.
The RF part of the receiver is a temperature sensitive component. Avoid high temperature drift
and air vents near the receiver.
Non 'emitting'
circuits
PCB
Digital & Analog circuits
Non
'emitting'
circuits
A
n
ten
n
a
Digital Part
RF Part
1
2
3
4
5
6
7
8
9
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11
12
13
14
28
27
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25
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15
RF & heat
'emitting'
circuits
PCB
Digital & Analog circuits
RF& heat
'emitting'
circuits
A
n
ten
n
a
1
2
3
4
5
6
7
8
9
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28
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Figure 11: Placement
3.3.3
Antenna connection and ground plane design
u-blox 7 modules can be connected to passive or active antennas. The RF connection is on the PCB and connects
the
RF_IN
pin with the antenna feed point or the signal pin of the connector, respectively. Figure 12 illustrates
connection to a typical five-pin RF connector. One can see the improved shielding for digital lines as discussed in
the
GPS Antenna Application Note
[6]. Depending on the actual size of the ground area, if possible place
additional vias in the outer region. In particular, terminate the edges of the ground area with a dense line of vias.
