User`s guide

60 N9320A Spectrum Analyzer
3 Functions and Measurements
Making a Reflection Calibration Measurement
The following procedure makes a reflection measurement
using a coupler or directional bridge to measure the return
loss of a filter. This example uses a 370 MHz lowpass filter
as the DUT.
The calibration standard for reflection measurements is
usually a short circuit connected at the reference plane (the
point at which the device under test (DUT) is connected.)
See Figure 22, a short circuit has a reflection coefficient of
1 (0 dB return loss). It reflects all incident power and
provides a convenient 0 dB reference.
1 Connect the DUT to the directional bridge or coupler as
shown in Figure 22. Terminate the unconnected port of the
DUT.
Figure 22 Reflection Measurement Short Calibration Test Setup
Remote
Standby
On
TG SOURCE CAL OUT
50MHz
10dBm
7
·
4
1
0
2
5
89
6
3
Back
Ent er
Marker
Peak
Search
Marker
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Tune
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N9320A SPECTRUM ANALYZER 9 kHz - 3.0 GHz
PROBE PO WER
RF IN 50
50VDC MAX
30dBm 1W MA X
CAT Ⅱ
Short
Circuit
DUT
Directional
Bridge/Coupler
Coupled Port
Reference Plane
or