Sunsea AIoT SimCom SIM7090G User Manual page 51

SIM7090G User Manual V1.01
4.3.2. GNSS Application Guide
Users can adopt an active antenna or a passive antenna to SIM7090G. The following figures are the
reference circuits.
Figure 26: Active antenna circuit
Figure 27: Passive antenna circuit (Default)
In the above figures, components C1, L1 and L2 are used for antenna matching. Usually, the value of the
component can only be obtained after the antenna is tuned, and is usually provided by the antenna supplier.
C2 is used for DC blocking. The active antenna's VDD requires an external power supply and should be
considered according to the characteristics of the active antenna. It is recommended to use LDO/DCDC to
turn off the active antenna when GNSS is not working to reduce current consumption.
GNSS can be tested through the NMEA port. NMEA sentences can be obtained automatically via UART or
USB. NMEA sentences include GSV, GGA, RMC, GSA and VTG. Before using GNSS, users should
configure SIM7090G to the correct working mode through AT commands. For more information, please
refer to the relevant documentation. SIM7090G can also obtain location information directly through AT.
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