Specifications

118 Chapter 13
Stimulus Response Measurements (ESA Options 1DN and 1DQ)
Making a Reflection Calibration Measurement
Stimulus Response Measurements
(ESA Options 1DN and 1DQ)
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 200 MHz bandpass 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 13-7. 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.
Step 1. Connect the DUT to the directional bridge or coupler as shown in
Figure 13-7. Terminate the unconnected port of the DUT.
Figure 13-7 Reflection Measurement Short Calibration Test Setup
NOTE If possible, use a coupler or bridge with the correct test port connector
for both calibrating and measuring. Any adapter between the test port
and DUT degrades coupler/bridge directivity and system source match.
Ideally, you should use the same adapter for the calibration and the
measurement. Be sure to terminate the second port of a two port device.
Step 2. Connect the tracking generator output of the analyzer to the directional
bridge or coupler.
Step 3. Connect the analyzer input to the coupled port of the directional bridge
or coupler.
Step 4. Perform a factory preset:
Press
Preset, Factory Preset (if present).