User's Manual

SIM7075G User Manual V1.00
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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
SIM7075G in proper operating mode by AT command. Please refer to related documents for details.
SIM7075G can also get position location information through AT directly.
1. GNSS is closed by default and can be started by “AT+CGNSPWR=1”. The AT command has two
parameters, the first is on/off, and the second is GNSS mode. Default mode is standalone mode.
AGPS mode needs more support from the mobile telecommunication network. Please refer to
document [21] for more details.
2. If the passive antenna is used, put the LNA close to the antenna.
3. Make sure there are no noise signals around GNSS antenna.
4.4 RF traces note
4.4.1 RF traces layout

Keep the RF trace from module ant pin to antenna as short as possible
 RF trace should be 50 Ω either on the top layer or in the inner layer
 RF trace should be avoided right angle and sharp angle.
 Put enough GND vias around RF traces.
 RF trace should be far away from other high speed signal lines.
NOTE