u-blox ZED-F9P Integration Manual page 76

Figure 51: ZED-F9P Antenna Supervisor
The bias-t inductor must be chosen for multi-band operation: a value of 120 nH 5% is
recommended
L1: MURATA LQW15A 0402 120N 5% 0.11A -55/+125C
C2: MURATA GRM033R71C103KE14 CER X7R 0402 10N 10% 16V
ESD protection diode on RF trace TYCO, 0.25PF, PESD0402-140 -55/+125C
5.3.10.1 Antenna voltage control - ANT_OFF
Antenna status (as reported in UBX-MON-RF and UBX-INF-NOTICE messages) is not
reported unless the antenna voltage control, ANT_OFF, has been enabled.
Set antenna voltage ON:
CFG-HW-ANT_CFG_VOLTCTRL = 1
Result:
• MON-RF in u-center: Antenna status = OK. Antenna power status = ON
• ANT_OFF pin = active high to turn antenna off therefore the pin is low to enable an external
antenna.
Start up message at power up if configuration stored:
$GNTXT,01,01,02,ANTSUPERV=AC *00
$GNTXT,01,01,02,ANTSTATUS=INIT*3B
$GNTXT,01,01,02,ANTSTATUS=OK*25
ANTSUPERV=AC indicates antenna control is activated
5.3.10.2 Antenna short detection - ANT_SHORT_N
Then to set Short circuit detect ON:
CFG-HW-ANT_CFG_SHORTDET = 1
UBX-18010802 - R02
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5 Hardware description
ZED-F9P - Integration Manual
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