ZOE-M8 series - Hardware Integration Manual
UBX-16030136 - R07 Production Information Design-in
Page 23 of 32
Figure 17: In-band interference sources
Measures against in-band interference include:
• Maintaining a good grounding concept in the design
• Shielding
• Layout optimization
• Filtering e.g. resistors and ferrite beads
• Placement of the GNSS antenna
• Adding a CDMA, GSM, WCDMA band-pass filter before handset antenna
2.13.6.4 Out-band interference
Out-band interference is caused by signal frequencies that are different from the GNSS carrier (see Figure 18). The
main sources are wireless communication systems such as GSM, CDMA, WCDMA, Wi-Fi, BT, etc.
Figure 18: Out-band interference signals
Measures against out-band interference include maintaining a good grounding concept in the design and adding
a SAW or band-pass ceramic filter (as recommend in section 2.13.6) into the antenna input line to the GNSS
receiver (see Figure 19).
Figure 19: Measures against out-band interference