RIGOL DG4000 Series - Manual (Page 137)

Chapter 6 Sweep RIGOL
DG4000 Series User’s Guide 6-3
Center Frequency and Frequency Span
You can also set the frequency boundaries of frequency sweep through center
frequency and frequency span.
 Center Frequency = (|Start Frequency + End Frequency|) / 2
 Frequency Span = End Frequency – Start Frequency
When frequency sweep is enabled, press Start/Center to highlight “Center”.
Notice that, “Span” in End/Span will also be highlighted. Use the numeric
keyboard or direction keys and knob to enter the desired frequency values. By
default, the center frequency is 550Hz and the frequency span is 900Hz.
Different sweep waveform corresponds to different center frequency and
frequency span range and center frequency and frequency span are interrelative.
Define the minimum frequency of the waveform currently selected as
min
F
, the
maximum frequency as
max
F
and
2 / ) (
max min
F F F
m
+ = .
 The range of center frequency is from
min
F
to
max
F
and the parameters for
different waveforms are as follows:
Sine: 1μHz to 160MHz
Square: 1μHz to 50MHz
Ramp: 1μHz to 4MHz
Arb: 1μHz to 40MHz
 Frequency span range is influenced by the center frequency:
Center frequency <
m
F
: frequency span range is ±2× (center frequency
–
min
F
);
Center frequency ≥
m
F
: frequency span range is ±2× (
max
F
– center
frequency).
Take sine as an example.
min
F
is 1μHz,
max
F
is 160MHz and
m
F
is about
80MHz.