Directional Couplers - R&S N 8000 Series System Manual

1.6.2

Directional Couplers

Fig. 26 Directional couplers
The forward and reflected power is detected at the transmitter output by means of the fre-
quency-compensated directional couplers P14A (forward) and P14B (reflected). The fre-
quency-compensated directional couplers output a power-proportional DC voltage to the
R&S NetCCU800 transmitter control unit via the integrated rectifier circuit. The DC voltages
for forward and reflected power are displayed in the R&S NetCCU800 and also used as an
S measurement for VSWR monitoring (reflection on the antenna).
Directional coupler P14C is a free test point that can be used either as a forward or reflected
power test point.
The P14D rectifier is used in the digital TV transmitter only in combination with the ADE op-
tion.
The transmitter is switched off due to reflection if the reflected value exceeds 2% of the for-
Note
ward value after being checked three times.
2098.0188.72
Chapter 2
- 2.22 -
Design and Characteristics
E-1