ZOE-M8B - System Integration Manual
UBX-17045131 - R04
Contents
Page 29 of 42
Production Information
Figure 22: 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 bandpass filter before handset antenna
2.14.6.4
Out-band interference
Out-band interference is caused by signal frequencies that are different from the GNSS carrier (see
Figure 23). The main sources are wireless communication systems such as GSM, CDMA, HSPA, Wi-
Fi, Bluetooth, etc.
Figure 23: 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 2.14.6) into the antenna input
line to the GNSS receiver (see Figure 24).
Figure 24: Measures against out-band interference
