Atec Rohde-Schwarz-UPL - Manual (Page 21)

Audio Analyzer UPL 21
FFT analyzer
Frequency range
Digital 48/96 kHz DC to 21.9/43.8 kHz
ANLG 22/110 kHz DC to 21.9/110 kHz
Dynamic range
Digital > 135 dB
ANLG 22 kHz 120 dB/105 dB 1)
ANLG 110 kHz 115 dB/85 dB 1)
Noise floor
Digital –160 dB
ANLG 22 kHz –140 dB/110 dB 1)
ANLG 110 kHz –120 dB/90 dB 1)
FFT size 256, 512, 1k, 2k, 4k, 8k points
(16k with zoom factor 2)
Window functions rectangular, Hann, Blackman-Harris,
Rife-Vincent 1-3, Hamming, flat top,
Kaiser (ß = 1 to 20)
Resolution from 0.05 Hz with zoom, from 5.86 Hz
without zoom
Zoom 2 to 128 (2 to 16 mit ANLG 110)
Averaging 1 to 256, exponential or normal
Typical noise floor of FFT analysis at analog inputs
Filter
For all analog and digital analyzers. Up to 3 filters can be combined as re-
quired. All filters are digital filters with a coefficient accuracy of 32 bit floating
point (exception: analog notch filter).
Weighting filters – A weighting
– C message
– CCITT
– CCIR weighted, unweighted
– CCIR ARM
– deemphasis 50/15, 50, 75, J.17
– rumble weighted, unweighted
– DC noise highpass
– IEC tuner
– jitter weighted
1) With/without analog notch filter.
User-definable filters
8th order elliptical, type C (for highpass and lowpass filters also 4th order),
passband ripple +0/–0.1 dB, stopband attenuation approx. 20 dB to 120 dB
selectable in steps of approx. 10 dB (highpass and lowpass filters: stopband
attenuation 40 to 120 dB).
Highpass, lowpass filters limit frequencies (–0.1 dB) selectable,
stopband indicated
Bandpass, bandstop filters passband (–0.1 dB) selectable,
stopband indicated
Notch filter center frequency and width (–0.1 dB)
selectable, stopband indicated
Third octave and octave filters center frequency selectable,
bandwidth (–0.1 dB) indicated
File-defined filters any 8th order filter cascaded from
4 biquads, defined in the z plane by
poles/zeroes or coefficients
Analog notch filter
For measurements on signals with high S/N ratio, this filter improves the dynamic
range of the analyzer by up to 30 dB to 140 dB for analyzer 22 kHz, or 120 dB
for analyzer 110 kHz (typical noise floor of FFT). The filter is also used for mea-
suring THD, THD+N and MOD DIST with dynamic mode precision.
Characteristics available in analog analyzers
with measurement functions:
– rms, wideband
– rms, selective
– quasi-peak
– FFT analysis
Frequency range 10 Hz to 22.5 kHz center frequency (f
c
)
Frequency tuning – automatic to input signal
– coupled to generator
– fixed through entered value
Stopband typ. > 30 dB, f
c
± 0.5%
Passband typ. –3 dB at 0.77 x f
c
and 1.3 x f
c
,
typ. +0/–1 dB outside 0.5 x f
c
to 2 x f
c
Sweep
Generator sweep
Parameters
frequency, level,
with bursts also interval and duration,
one- or two-dimensional
Sweep linear, logarithmic, tabular,
single, continuous, manual
Stepping – automatic after end of measurement
– time delay (fixed or loaded table)
Analyzer sweep
Parameters
frequency or level of input signal
Sweep single, continuous
Trigger – delayed (0 to 10 s) after input level or
input frequency variation, settling
function selectable
– time-controlled
Settling for level, frequency, phase, distortion
measurements,
settling function: exponential, flat or
averaging
Sweep speed
Two-channel rms measurement 20 Hz to 20 kHz, 30-point generator sweep
logarithmic (frequency measurement switched off, Low Dist off).
with GEN TRACK 0.5 s
AUTO FAST 1 s
AUTO 2.5 s