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Figure 7: SIM68R passive antenna design for best performance
4.7.2.2
Active Antennas
Active antennas have an integrated Low-Noise Amplifier (LNA). They can be directly connected to
RF_IN
. If an
active antenna is connected to
RF_IN
, the LNA of the antenna needs to be supplied with the correct voltage
through pin
V_ANT
. Usually, the supply voltage is fed to the antenna through the coaxial RF cable shown as
Figure 8. The output voltage of PIN 18 is 2.8V. If the supply voltage of active antenna is 2.8V,
VCC_RF
can
supply the voltage through the pin
V_ANT
.
Figure 8: SIM68R Active antenna design
SIM68R_Hardware Design_V1.02
22
2013-01-22