Contec VNA-300M-PCI, Руководство пользователя, Страница: 34 / 55

3. External Connection
VNA-300M-PCI
27
Reflection Measurement
This section provides an example of connecting to a passive part or circuit that has an I/O impedance of
50Ω.
To perform reflection measurements, a separate directional coupler is required in order to isolate the
reflected wave from the signal wire.
O
UT
IN
T
R
G
E
X
T
R
E
F
DUT
OUT
I N I N
CPL
Directinonal coupler
Figure 3.5. Connection to the DUT
CAUTION
- If you will perform reflection measurements, set the pi-circuit setting to OFF. Failing to do so may
prevent normal measurements from being performed. Use Device Manager to set the pi-circuit
setting to ON or OFF.
- Accurate measurements may not be possible if this product and the device under test are affected by
noise or if there is a large distance between this product and the device under test.
- The output from the OUT terminal is uncertain immediately after the computer starts (for a few
seconds after the power turns on).