Two-port measurements with the tracking generator R&S FSH
1145.5973.12 4.96 E-11
In the third step of calibration, terminate the
measurement port into a 50 termination.
Terminate the measurement input of the bridge or
the end of the measurement cable into a
50 termination.
Start termination calibration by pressing the first or
the second softkey (CONTINUE). During
calibration, the R&S FSH outputs the message
"Calibrating LOAD, please wait...".
When calibration is over, the R&S FSH outputs the
message "Reflect. calibrated" for three seconds.
Refl (vect) is displayed in the top right-hand corner of
the diagram to indicate that the R&S FSH is vector-
calibrated for reflection measurements. The softkey
label REFLECT CAL is highlighted in green.
The reflection calibration remains valid until the center frequency or the span is changed on the
R&S FSH. Track Gen Uncal is displayed in the top right-hand corner of the screen when calibration is
no longer valid.
If the reference level is changed (AMPT key, REF softkey) after calibration, greater measurement
uncertainty must be anticipated. The R&S FSH retains the calibration data but displays a red dot before
the • Refl (vect) display in the top right-hand corner of the screen to indicate a possible increase in
measurement uncertainty.
A change in sweep time does not affect reflection measurement.
The R&S FSH internally monitors the temperature. If temperature changes cause an increase in
measurement error, the R&S FSH shows a red dot to the left of the measurement mode display
( • Refl (vect) ).
Display of reflection in vector measurement
Since the R&S FSH also evaluates the magnitude and phase during measurements following vector
calibration, additional display capabilities are available as compared to scalar measurement. Owing to
the larger dynamic range, the display ranges for the standing wave ratio (VSWR) and VSWR 1 –1.5 and
VSWR 1 –1.1 are expanded. Thus, well matched DUTS can be measured with greater precision and
higher display resolution.
However, one of the main advantages of vector measurement is also being able to display the complex
measurement results in a Smith chart. This provides a much more in-depth look at the characteristics of
the DUT than by displaying the reflection magnitude as return loss or VSWR.
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