MIA-M10Q - Integration manual
Figure 28: Spectrum analyzer view in u-center with the option view/hold selected
By changing the number of constellations enabled, the span widens or narrows. This has
a direct impact on the spectrum resolution, as the number of frequencies measured is
fixed and equals to 256. For further details about this message and how to calculate each
frequency, see the interface description [
A big spur may be visible in the center frequency. The signal comes internally from the
receiver and it does not cause any degradation in the performance.
3.4 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 MIA-M10Q RF front-end is designed for the highest sensitivity. The integrated RF circuit is
matched to 50 Ω and includes a built-in DC block, an LTE Band 13 notch filter, an LNA, and an SAW
filter. Refer to the
for an overview of the RF front-end. The MIA-M10Q offers the best
GNSS performance for designs with low or moderate RF interference levels.
For designs with other radio systems, an external SAW filter may be required to improve the
immunity against RF interference. The external SAW filter converts the MIA-M10Q RF front-end
into an SAW - Band 13 notch - LNA - SAW circuit for the highest immunity, complete with built-in
LTE Band 13 protection. The external SAW filter can be selected for an optimal trade-off between
sensitivity and immunity.
3.4.1 Internal LNA modes
The internal LNA in MIA-M10Q has three operating modes: normal gain, low gain and bypass mode.
• By default, the internal LNA is configured for the low-gain mode for optimized sensitivity and
immunity against RF interference.
• For RF front-end designs with 10 - 15 dB or higher total external gain, bypass mode is
recommended to improve immunity. The power consumption is also slightly reduced in bypass
mode.
UBX-21028173 - R01
3 Hardware integration
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