Layout Guidelines; Layout Underneath The Module - Sierra Wireless AirPrime XS1110 Product Technical Specification

Rev 4.0 Jul.20

Layout Guidelines

The following layout guidelines should be followed during the design process.

Layout Underneath the Module

The XS1110 modules have high receiving sensitivity at around -161 dBm. During
hardware integration, try to avoid noise or harmonics in the following bands to
prevent unnecessary reception degradation:
• GPS — 2.046 MHz BW NB GPS (centered on 1575.42 MHz)
• Glonass (GLO) — ~8.3 MHz BW (1597–1606 MHz), 14 channels (-7 to +6)
• BeiDouSystems (BDS) — 4.092 MHz BW (1559.05 –1563.14 MHz)
• Galileo (GAL) — 4.092 MHz BW (centered on 1575.42 MHz)
Modern GNSS positioning products integrate many components such as an LCD
screen, MCU, high speed digital signal (access memory card) and RF system (i.e.
cellular module, BT, Wi-Fi, DVB-T). These may cause poor GNSS RF reception;
keep these components away from the module to avoid noise interference.
Do not leave any trace or mark underneath the XS1110 as indicated by the red
area in the following figure:
Figure 5-6: Module with a Clean GND Plane
Also, do not place any trace such as I2C (SCL/SDA), USB (DP/DN) or UART (TX/
RX) underneath the XS1110 as this will cause a decrease in sensitivity.
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General Rules for Circuit Design
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