Furuno GN-86F User Manual page 6

Figure 2-2 shows an overview of the RF section PCB design for using the passive antenna.
There is no need to bias the antenna, so 39nH inductor and 33pF capacitor are removed from Figure 2-1.
But λ/4 short stub is placed to keep the higher robustness against ESD noise.
The routing between the passive antenna and RF_IN should be designed as 50Ω microstrip line, and there
is no need to place any matching network externally as same as the active antenna case.
: 1.5GHz / 1.6GHz 50Ω Micro Strip Line
: Ground
:λ/4 Short Stub
Passive Antenna
(Patch Antenna)
Figure 2-2 RF Section PCB Layout Design Overview for Passive Antenna
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FURUNO GPS/GNSS Receiver 86/87 Series User's Design Guide
50Ω Microstrip Line
2
SE13-900-001-06
86/87 Series
Module
#10 GND
#11 RF_IN
#12 GND
λ/4 Short Stub