Gnss Receiver; Gnss Specification; Gnss Observes Protocol; Antenna Design - Fibocom NL668-LA Hardware User Manual

7.4 GNSS Receiver

7.4.1 GNSS specification

NL668-LA series module support GNSS function and adopts Qualcomm Gen8 technology, its
specification show as follows:
Description
Power
（AT+CFUN=0）
TTFF
Sensitivity
Positional accuracy

7.4.2 GNSS observes protocol

NL668-LA series module adopt NMEA-0183 protocol.

7.5 Antenna design

7.5.1 Antenna index

1) Antenna efficiency
Antenna efficiency is the ratio of antenna input power to radiated power. Due to the antenna return loss,
material loss, and coupling loss, the radiated power is always lower than the input power. Recommend>
40% (-4dB).
2) S11 or VSWR
S11 shows that the matching degree of the antenna's 50 ohm impedance, to a certain extent, affects the
antenna efficiency. VSWR test methods can be used to measure this parameter. Recommend S11
<-10dB.
3) Polarization
Polarization is the rotation direction of the electric field in the maximum radiation direction of the antenna.
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FIBOCOM NL668-LA Series Hardware User Manual
GNSS tracking
Cold start<58s
GNSS Warm start<70s
Acquisition
Tracking
CN0 GNSS Signal@-130dBm
CEP GNSS Signal@-130dBm
Table 7- 5 GNSS Specification
Condition
GNSS
fixing
Standby
Hot Start<8s
Typ.
70mA
70mA
34mA
58s
50s
7.5s
-144dbm
-155dbm
38.5 dB-Hz
<3.5m
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