Rohde & Schwarz R&S UPP, Руководство пользователя

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Instrument Functions
R&S
®
UPP
454 User Manual 1411.1055.32 ─ 10
"Fast" The frequency and (if applicable) phase measurement is optimized
with respect to speed. A 4
k FFT is used as the measurement basis
for high frequencies and the phase; low frequencies are determined
by means of an evaluation of period (with interpolation). This measur-
ing mode does not require any additional processing performance,
i.e. the total measurement time of all activated measurement func-
tions does not increase.
Recommended for pure frequency measurements on single-tone sig-
nals or for phase measurements on signals whose frequency is not
too low (higher than 2
% of the bandwidth and 1 % of the sampling
frequency).
Note: In the case of distortion measurements the frequency must be
very accurately determined. The accurate result of this frequency
measurement is then displayed. The frequency accuracy in fast mode
therefore depends on the measurement function selected.
"Prec" The frequency and (if applicable) phase measurement is optimized
with respect to precision. A precision FFT with up to 256
k points is
used as the measurement basis. The FFT length is automatically
adapted to the measured signal frequency so that measurement can
always be performed with the smallest possible FFT (and, therefore,
in the shortest possible time).
Depending on the activated measurement function, the total mea-
surement time can increase in this measuring mode since it may be
necessary to calculate an (additional) FFT.
Note: Digital or analog filters which are active in the activated func-
tion measurement are also used in the frequency measurement. If
only the unfiltered frequency or phase measurement result is
required, the function measurement should be deactivated.
Recommended for signals with a high noise component, multi-tone
signals and for measuring the phase of low frequencies.
Remote command:
SENSe3:FREQuency:APERture:MODE
on page 770
Format Phase
Used to select the phase display format; only available if phase measurement is activa-
ted.
or
Frequency, Phase and Group Delay Measurement