MAX-7 / NEO-7 - Hardware Integration Manual
UBX-13003704
-
R09
Production Information
Design
Page
25 of 52
3.4.2.1
Active antenna design, VCC_RF used to supply active antenna
Figure 19 shows an active antenna design supplied by VCC_RF.
Figure 19: Active antenna design, external supply from VCC_RF
3.4.2.2
Active antenna design powered from external supply
Figure 20 shows a design with direct externally powered active antenna.
This circuit works with all u-blox 7 modules, also with modules without VCC_RF output.
Figure 20: Active antenna design, direct external supply
For recomended parts, see section 3.5.
In case VCC_RF voltage does not match with the antenna supply voltage, use a filtered external supply as
shown in Figure 20.
3.4.3
Antenna design with active antenna using antenna supervisor
(MAX-7W)
An active antenna supervisor provides the means to check the antenna for open and short circuits and to shut
off the antenna supply if a short circuit is detected. The Antenna Supervisor is configured using serial port UBX
binary protocol message. Once enabled, the active antenna supervisor produces status messages, reporting in
NMEA and/or UBX binary protocol (see section 3.4.3.1). These indicate the particular state of the antenna
supervisor shown in the state diagram below (Figure 21).
The current active antenna status can be determined by polling the UBX-MON-HW monitor command. If an
antenna is connected, the initial state after power-up is “Active Antenna OK.”
