ZED-F9T - Integration Manual
Figure 11: ZED-F9T antenna supervisor
The bias-t inductor must be chosen for multi-band operation; a value of 120 nH 5% is
required for our recommended Murata part if current is limited below its 110 mA rating. See
antenna bias
section for additional information.
Circuit shows buffer [U4]. Buffer is not strictly necessary when supplied from VCC. It is only
required when supplying antenna voltage that is not obtained from or controlled by module
VCC or VCC_RF .
L1: 300 mA and >500 Ω at L-band frequencies
C2: MURATA GRM033R71C103KE14 CER X7R 0402 10N 10% 16V
ESD protection diode on RF trace TYCO, 0.25PF, PESD0402-140 -55/+125C
3.3.9.1 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 has been enabled.
Enable the antenna voltage control by setting the configuration item CFG-HW-
ANT_CFG_VOLTCTRL to true (1).
Result:
• UBX-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
UBX-19005590 - R01
3 Receiver functionality
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