ADInstruments DSA2016TG, Руководство пользователя, Страница: 23 / 69

Direction Key Step in 1, 2, 5 sequence
3.1.2 SPAN
Set the span of the analyzer. The change of this parameter will affect the frequency parameters
and restart the sweep.
Span
Set the frequency range of the current channel. Press this key to switch to center frequency/span
input mode and the center frequency and span are displayed at the lower left and right sides of
the grid respectively.
Key Points:
• The start and stop frequencies vary with the span automatically.
• In manual span mode, the span can be set down to 100 Hz (the only way into the zero-span
mode is pressing the
Zero Span menu option) and up to the full span described in
“ Specifications ”. When the span is set to the maximum, the analyzer enters full span mode.
• Modifying the span in non-zero span mode may cause an automatic change in both CF step
and RBW if they are in Auto mode, and the change of RBW may influence VBW (in Auto
VBW mode).
• Variation in the span, RBW or VBW would cause a change in the sweep time.
• You can modify this parameter using the numeric keys, knob, or direction keys. For more
details, please refer to “
Parameter Setting ”.
Span Parameter Explanation
Default 1.6GHz (1.6GHz)
Range* 0 Hz to 1.6GHz (1.6GHz)
Unit GHz, MHz, kHz, Hz
Knob Step Span/200, Min = 1 Hz
Direction Key Step in 1, 2, 5 sequence
*
Note: 0 Hz is available only in zero span.
Full Span
Set the span of the analyzer to the maximum.
Zero Span
Set the span of the analyzer to 0 Hz. Both the start and stop frequencies will equal the center
frequency and the horizontal axis will denote time. The analyzer measures the time domain
characteristics of the amplitude of the corresponding frequency point on the input signal.
Key
Points: As opposed to the Non-zero span, the screen shows the time domain characteristics of
the fixed frequency component in zero span mode.The following functions are invalid in Zero span
mode:
“Zoom In” and “Zoom Out” in SPAN
Zoom In
Set the span to half of its current value. At this point, the signal on the screen is zommed in on to
observe signal details.
Zoom Out
Set the span to twice the current value. At this point, the signal on the screen is zoomed out on to