User Manual

Smart Machine Smart Decision
SIM7100_Hardware_Design_V1.02 2015-06-16
Note: If the antenna is active type, the power should be given by main board, because there is no
power supply on GPS antenna pad. If the antenna is passive, it is suggested that the external
LNA should be used.
4.3.2 GNSS Application Guide
Users can adopt an active antenna or a passive antenna as GNSS signal transceiver. In this
document, all GNSS specification mentioned is from passive antenna. The following is the
reference circuit.
Figure 35: Active antenna circuit
Figure 36: Passive antenna circuit (Default)
In above figures, the components C1 and L1, L2 are used for antenna matching, the values of the
components can only be obtained after the antenna tuning usually, and they are provided by
antenna vendor.C2 in Figure 35 is used for DC isolation. In active antenna circuit, users must use
an external LDO/DCDC to provide VDD voltage whose value should be taken according active