R&S FSW Series, Руководство пользователя

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Common Measurement Settings
R&S
®
FSW
451 User Manual 1173.9411.02 ─ 43
For ideal sinusoidal signals, the displayed signal level is independent of the RF attenu-
ation.
Depending on the type of measurement you must find a compromise between a low
noise floor and high intermodulation levels, and protecting the instrument from high
input levels. You achieve this best by letting the R&S
FSW determine the optimum
level automatically (see "Attenuation Mode / Value" on page 454).
Electronic attenuation
If the optional electronic attenuation hardware is installed on the R&S FSW, you can
also activate an electronic attenuator. For details, see "Using Electronic Attenuation"
on page 454.
8.4.1.3 Scaling
In a linear display, the measurement values are distributed linearly throughout the grid.
That means the entire range of measured values is divided by the number of rows in
the grid (10) and each row corresponds to 1/10 of the total range. Linear scaling is use-
ful to determine precise levels for a small range of values. However, if large and small
values appear in the same display, it is difficult to determine individual values precisely
or to distinguish values that are close together.
In a logarithmic display, smaller values are distributed among a much larger area of the
display, while large values are condensed to a smaller area. Now it is much easier to
distinguish several lower values, as they are spread over a wider area. Logarithmic
scaling is useful when large ranges of values must be combined in one display. Loga-
rithmic scaling is best applied to measurement values in logarithmic units (dB, dBm
etc.).
In addition to linear or logarithmic scaling, the vertical axis can be set to display either
absolute or relative values. Absolute values show the measured levels, while relative
values show the difference between the measured level and the defined reference
level. Relative values are indicated in percent for linear scaling, and in dB for logarith-
mic scaling.
8.4.2 Amplitude Settings
Access : "Overview" > "Amplitude"
Amplitude settings determine how the R&S FSW must process or display the expected
input power levels.
The remote commands required to define these settings are described in Chap-
ter 14.7.3.1, "Amplitude Settings" , on page 1039.
Amplitude and Vertical Axis Configuration