V1.4 – Mar-11
User’s Manual
Page 29 of 39
8.2.2 Passive Antennas
A passive antenna connected to
ANT_INT
should be placed as close as possible to
the GPS receiver. The signal power lost by the antenna cable or lost by the strip line
on the PCB can not be recovered by the LNA (Low Noise Amplifier) integrated in the
GPS receiver.
A suitable Ground-Plane design should be considered depending on the antenna
type connected to ANT_INT.
8.2.3 Active Antennas on ANT_INT
If an active antenna needs to be used on the passive antenna input (ANT_INT), the
supply voltages needs to be fed separately.
Figure 14: External power supply for active antenna
8.2.4 Hints
Unused antenna inputs should be terminated with 50
Ω
±
20%. Do not feed antenna
supply voltage into terminated antenna inputs.