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Center frequency and frequency span, Center frequency and frequency span -58 – RIGOL DG1000Z Series User Manual

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RIGOL

Chapter 2 Front Panel Operations

2-58

DG1000Z User’s Guide

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 + Stop Frequency|) / 2
 Frequency Span = Stop Frequency – Start Frequency

When sweep mode is enabled, press Start/Center to highlight “Center”. Notice

that the “Span” in Stop/Span will also be highlighted at the same time. 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 the 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 60MHz

Square: 1μHz to 25MHz

Ramp: 1μHz to 1MHz

Arb: 1μHz to 20MHz

 The range of frequency span is influenced by the center frequency.

Center frequency <

m

F

: the range is ±2× (center frequency –

min

F

);

Center frequency ≥

m

F

: the range is ±2× (

max

F

– center frequency).


Take sine as an example.

min

F

is 1μHz,

max

F

is 60MHz and

m

F

is about 30MHz.

If the center frequency is 550Hz, the frequency span range is ±2×(550Hz–1μHz) =

±1.099999998kHz; if the center frequency is 55MHz, the frequency span range is

±2×(60MHz–55MHz) = ±10MHz.

The generator will renewedly sweep (according to the current new configuration)

from the specified “start frequency” after center frequency” or frequency span is

changed.

TIP:

In large-scale sweep, the amplitude characteristic of the output signal might

change.