Rohde & Schwarz 1336.5401.02, Руководство пользователя, Страница: 42 / 123

Operating the R&S QAR
R&S
®
QAR
42 User Manual 1178.7200.02 ─ 09
remove those deviations from the actual measurement results, which in turn improves
the accuracy of the measurement.
Normalizing reflection measurements
Normalizing the reflection measurement requires a clean, smooth and flat metallic
plate for a high reflection, for example aluminum. The recommended size is between
100
mm x 100 mm and 200 mm x 200 mm.
If you have the verification objects, and it fits your setup, you can use the plate labeled
E to normalize the reflection.
1. Place the plate at the same location where you are going to mount the DUT for the
actual measurement.
Make sure that the plate is parallel to the R&S
QAR. We recommend using the
same fixture for the metal plate as for the DUT.
2. Select the "Normalize Reflection" button to initiate the measurement.
When the normalization measurement is done, the R&S QAR saves the correction
data. All subsequent measurements are corrected accordingly.
A valid normalization results in an image with high reflection. The mean reflection
should be approximately 0
dB and should not exceed a certain deviation from that
value - refer to the datasheet for exact values.
3. Optional: Scan the metal plate with the "Measure" button to verify the normaliza-
tion.
If the results do not meet the expectations, repeat the normalization.
If the second normalization still yields unexpected results, verify the test setup. For
details about the verification procedure, see
Chapter 5.1.5, "Verification" ,
on page 50.
Normalizing the transmission measurement
Normalizing the transmission measurement is done by a free-space measurement and
requires no additional devices. However, make sure that the line of sight between
R&S
QAR and transmitter module is free of obstacles.
1. Select the "Normalize Transmission" button to initiate the measurement.
When the normalization measurement is done, the R&S QAR saves the correction
data. All subsequent measurements are corrected accordingly.
2. Optional: scan the free space with the "Measure" button to verify the normalization.
A valid normalization results in a straight trace at approximately 0 dB attenuation.
The trace should not exceed a certain deviation from that value - refer to the data-
sheet for exact values.
If the results do not meet the expectations, repeat the normalization.
If the second normalization still yields unexpected results, verify the test setup. For
details about the verification procedure, see
Chapter 5.1.5, "Verification" ,
on page 50.
Radome Measurements