SAM-M10Q - Integration manual
detuned and the radiation efficiency significantly reduced. Placing the ground plane between the
body and the antenna minimizes the body effects on antenna performance.
3.3.2 RF front-end
GNSS receivers operate with very low signal levels, ranging from -130 dBm to approximately -167
dBm. This alone is a challenge for the GNSS application design. Out-of-band sources of interference
such as GSM, CDMA, WCDMA, LTE, Wi-Fi, or Bluetooth wireless systems with a much higher signal
level require additional specific measures. The goal of the RF front-end design is to receive the in-
band signal with minimum loss and added noise while suppressing the out-of-band interference.
The SAM-M10Q RF front-end is designed for high immunity against RF interference. The integrated
RF circuit between the antenna input terminal and the receiver RF input includes a pass-band SAW
filter followed by a low-noise amplifier (LNA). The SAW filter rejects out-of-band blocking signals
and the LNA amplifies the GNSS signal enhancing the sensitivity of the receiver. Refer to the
for an overview of the RF front-end. The SAM-M10Q offers high GNSS performance for
designs with moderate or high RF interference levels.
3.3.2.1 Out-of-band blocking immunity
Out-of-band RF interference may degrade the quality and availability of the navigation solution.
Out-of-band immunity limit describes the maximum power allowed at the receiver RF input with no
degradation in performance. Minor violation of the immunity limit may reduce C/N0 of the received
signals but does not necessarily affect the overall receiver performance. However, a significant
violation may reduce receiver sensitivity or cause a complete loss of signal reception. The severity of
the interference depends on the repetition rate, frequency, signal level, modulation, and bandwidth
of the signal.
A typical out-of-band immunity limit at SAM-M10Q antenna feed point is 0 dBm at 400 - 1460 MHz
and 1710 - 3300 MHz. The immunity decreases closer to the GNSS in-band. The limit is defined at
room temperature using a test signal with 64QAM modulation and 10 MHz bandwidth similar to an
LTE signal.
If the out-of-band immunity limit is exceeded, it is recommended to verify that the receiver
performance is not affected or is at an acceptable level in the presence of interference.
3.4 Layout
When integrating a GNSS receiver into a PCB, the placement of the components, as well as
grounding, shielding, and interference from other digital devices are crucial issues that need to be
considered very carefully.
SAM-M10Q GNSS patch antenna module is intended to be placed in the middle of a 50 x 50 mm
GND size board. A larger or a smaller ground plane can also be used. Note that when using a smaller
ground plane than 40 x 40 mm, the performance may decrease significantly. It is recommended not
to place anything closer than 10 mm to each edge of SAM-M10Q.
For applications using cellular antennas, increase the distance between both antennas as
much as possible.
shows an example of a PCB design. The yellow area represents the solid ground plane in the
top layer. The module is placed in the middle of the board and no signal traces are allowed below. If
necessary, keep at least 20 mm distance from the module edge when swapping any signal from the
top to other layers. The supply and digital lines of the module are short on the top layer and routed
to other layers.
UBX-22020019 - R01
3 Hardware integration
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