User's Manual

SIM7600G User manual
www.simcom.com
57
/
75
4.3.2 GNSS Application Guide
Users can adopt an active antenna or a passive antenna to MODULE. If using a passive antenna, an
external LNA is a must to get better performance.
The following figures are the reference circuits.
Figure 37: Active antenna circuit
Figure 38: Passive antenna circuit (Default)
In above figures, the components C1, L1 and L2 are used for antenna matching. Usually, the values of the
components can only be achieved after antenna tuning and usually provided by antenna vendor. C2 is used
for DC blocking. L3 is the matching component of the external LNA, and the value of L3 is determined by
the LNA characteristic and PCB layout. Both VDD of active antenna and V_LNA need external power
supplies which should be considered according to active antenna and LNA characteristic. LDO/DCDC is
recommended to get lower current consuming by shutting down active antennas and LNA when GNSS is
not working.
GNSS can be tested by NMEA port. NMEA sentences can be obtained through UART or USB automatically.
NMEA sentences include GSV, GGA, RMC, GSA, and VTG. Before using GNSS, user should configure
MODULE in proper operating mode by AT command. Please refer to related documents for details.
MODULE can also get position location information through AT directly.
Note: GNSS is closed by default and can be started by AT+CGPS. The AT command has two parameters,