Functions and Measurements 3
N9342C/43C/44C User’s Guide 53
Making a Reflection Calibration
The following procedure makes a reflection 
calibration using a coupler or directional bridge to 
measure the return loss of a filter. This example 
uses a 370 MHz low- pass filter as the DUT. The 
tracking generator (option TG7) is needed for this 
measurement. For N9342C handheld spectrum 
analyzer with option CA7 or CAU, please refer to 
the  “Measuring Cable Reflection" on page 77 to 
make a reflection measurement.
The calibration standard for reflection calibration 
is usually a short circuit connected at the reference 
plane (the point at which the DUT is connected). 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 below. Terminate the 
unconnected port of the DUT.
Figure 3-20 
Reflection Measurement Short Calibration Test Setup
N9340A  
HANDHELD SPECTRUM ANALYZER
 
 
 
100 kHz -  3.0  GHz
 
 PRESET
ENTER
 FREQ SPANAM PTD
BW/
SWP
SYS M ODE MEAS TRACE
ESC/CLR
2DEF 3 GHI1ABC
5MNO4JKL
6
PQR
8VWX7STU 9 YZ_
0SAV E
LIMIT
MARKER
 
Coupled Port
Short 
Circuit
DUT
or
2 Connect the tracking generator output of the 
analyzer to the directional bridge or coupler.
NOTE
If possible, use a coupler or bridge with the correct test port 
connector types for both calibrating and measuring. For the 
best results, use the same adapter for the calibration and the 
measurement. Terminate the second port of a two port device.