TFG2900A Series Function/Arbitrary Waveform Generator Users’ Guide
Suin Instruments Co., Ltd
49
3.14 Frequency Sweep
3.14.1 Function Selection:
Press
【
Sweep
】
to enter the frequency sweep function, at the same
time waveform diagram of frequency sweep and it’s menu are display.
3.14.2 To set Sweep signal:
Most built - in waveforms could be used as frequency sweep, but
some are not suitable. Press
【
CH1
】
to enter sweep signal’s parameter interface to set it’s
parameter. Please note that frequency and period cannot be set. During frequency sweep process,
the output frequency varies from the start frequency to the end frequency, the phase of output
signal is continuous, the sweep could be carried out during whole frequency range.
3.14.3 Sweep Mode
:
Press
〖
Type
〗
to select Linear or Log for sweeping.
In Linear mode, frequency step is fixed. For wide sweep range, fixed step has negative influence,
which leads to high sweep resolution, slow sweep speed and precise sweeping at high frequency,
but low sweep resolution, fast sweep speed and coarse sweeping at low frequency. Therefore,
linear is much applicable for narrow sweep range.
Linear sweep is similar as FM with modulating waveform ramp, the difference between which is
that no modulating wave needed for sweep, just output discrete points in interval continuously.
In Log mode, frequency step is not fixed but changes with log relationship. At high frequency, the
step is large and at low frequency step is less. For wide sweep range, the variation is relative
well-proportioned, so log sweep is applicable for wide sweep range.
3.14.4 Start Frequency and Stop Frequency:
Press the
〖
Start Freq
〗
or
〖
Stop Freq
〗
soft key.
Then use the knob or numeric keypad to enter the desired frequency.
To sweep up in frequency, set the start frequency less than the stop frequency.
To sweep down in frequency, set the start frequency be greater than the stop frequency.
3.14.5 Marker frequency:
Press
〖
Marker Freq
〗
soft key, then use the knob or numeric keypad to
enter the desired marker frequency. When sweeping cross the marker frequency point, the sync
output hop at the same time. The marker frequency must be set between the specified start
frequency and stop frequency.
3.14.6 Sweep Time:
Press
〖
Sweep Time
〗
soft key and use the knob or numeric keypad to enter
the desired sweep time. Sweep time represents the time required to sweep from the start frequency
to the stop frequency. The time interval to sweep from one frequency to next one is constant, so