User Manual 59
Different sweep waveform corresponds to different center frequency and frequency span range
and center frequency and frequency span are inter-related. Define the minimum frequency of the
waveform currently selected as
F
min, the maximum frequency as
F
max and
Fm =
(F
min
+F
max)
/
2.
The range of center frequency is from
F
min to
F
max and the parameters for different waveforms
are as follows:
Sine: 1μHz to 100MHz
Square: 1μHz to 30MHz
Ramp: 1μHz to 4MHz
Pluse: 1μHz to 15MHz
Arb: 1μHz to 20MHz
The range of the frequency span is influenced by the center frequency:
Center frequency <
F
m: frequency span range is ±2 × (center frequency -
F
min);
Center frequency ≥
F
m: frequency span range is ±2 × (
F
max- center frequency).
Take sine as an example.
F
min is 1μHz,
F
max is 100MHz and
F
m is about 500MHz.
If the center frequency is 550Hz, the range of the frequency span is:
±2 × (550Hz
– 1μHz) = ±1.099999998kHz;
if the center frequency is 90MHz, the range of the frequency span range is:
±2 × (100MHz
– 90MHz) = ±20MHz.
The generator will renewedly sweep from the specified "Start Frequency" after "Center
Frequency" or "Frequency Span" is changed.
Note: In large-scale sweep, the amplitude characteristic of the output signal might change.
6.4 Linear sweep
HDG2000B provides Linear sweep type.
The output frequency of the instrument varies linearly in the way of "several Hertz per second".
The variation is controlled by "Start Frequency", "End Frequency" and "Sweep Time".
6.5 Sweep Time
Sweep time specifies the number of seconds required to sweep from the start frequency to the
stop frequency. The instrument calculates the number of points in the sweep based on the sweep
time.
When
Sweep
is enabled, press
Sweep Time
and use the numeric keyboard or knob to change
