EVA-7M - Hardware Integration Manual
UBX-12003235 - R05
Production Information
Design-in
Page 24 of 42
2.12.6.4
Out-band interference
Out-band interference is caused by signal f
requencies that are different from the GNSS carrier (see
). The main
sources are wireless communication systems such as GSM, CDMA, WCDMA, WiFi, BT, etc.
0
500
1000
1500
2000
GPS input filter
characteristics
0
-110
0
500
1500
2000
Frequency [MHz]
GSM
900
GSM
1800
GSM
1900
Power [dBm]
GPS input filter
characteristics
GPS
1575
0
-110
GPS
signals
GSM
950
Figure 11: Out-band interference signals
Measures against out-band interference include maintaining a good grounding concept in the design and
adding a SAW or bandpass ceramic filter (as recommend in section 2.12.5) into the antenna input line to the
GNSS receiver (see Figure 10).
Figure 12: Measures against out-band interference
