User's Manual

LTE Module Series
EC21 Hardware Design
EC21_Hardware_Design Confidential / Released 59 / 94
Hot start
@open sky
Autonomous 2.5 s
XTRA enabled 1.8 s
Accuracy
(GNSS)
CEP-50
Autonomous
@open sky
<1.5 m
1. Tracking sensitivity: the lowest GNSS signal value at the antenna port on which the module can keep
on positioning for 3 minutes.
2. Reacquisition sensitivity: the lowest GNSS signal value at the antenna port on which the module can
fix position again within 3 minutes after loss of lock.
3. Cold start sensitivity: the lowest GNSS signal value at the antenna port on which the module fixes
position within 3 minutes after executing cold start command.
4.3. Layout Guidelines
The following layout guidelines should be taken into account in your design.
 Maximize the distance among GNSS antenna, main antenna and the Rx-diversity antenna.
 Digital circuits such as USIM card, USB interface, camera module, display connector and SD card
should be kept away from the antennas.
 Use ground vias around the GNSS trace and sensitive analog signal traces to provide coplanar
isolation and protection.
 Keep 50ohm characteristic impedance forthe ANT_GNSS trace.
Please refer to Chapter 5 for GNSS antenna reference design and antenna consideration.
NOTES