R&S
FS-K30
Measurements & Settings
Graphic
Settings
Software Manual 1300.6637.42 - 03
86
correction ON
, a measuring error of 3 dB will be produced. The noise figure is
displayed 3 dB lower and the gain 3 dB higher. The following examples help to
configure the test setup such that the actual values can be measured.
Measurement on a single-sideband mixer
IF 100 MHz; LO-Freq. 500 MHz; RF 400 MHz;
freq.
LO
RF
IF
In general, a single-sideband mixer with a very high image rejection causes very few
problems. The measurement is analogous to an amplifier. In this case set the
Image
Rejection
parameter in the Frequency Settings view to a large value (e.g. 999.99dB).
Measurement on a mixer without sideband suppression
IF: 100 MHz; LO-Freq.: 500 MHz; RF: 400 MHz; Image-Freq.: 600 MHz
freq.
LO
RF
IF
Image
If the input and image frequencies are converted with the same application, an error of
3 dB occurs in the measurement results if the image rejection is not taken into account.
In this case set the
Image Rejection
parameter in the Frequency Settings view to a
small value (e.g. 0.0 dB)
Measurements on a mixer with an average sideband suppression
IF: 100 MHz; LO-Freq.: 500 MHz; RF: 400 MHz; Image-Freq.: 600 MHz
freq.
LO
RF
IF
Image
4dB
For measurements on a mixer with a low image-frequency rejection, a measuring error
of 0 to 3 dB will be obtained if the image-frequency rejection is not taken into account.
For the above example setting the
Image Rejection
parameter in the Frequency
Settings view to 4 dB will produce the correct results
