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Acquisition and Waveform Setup
R&S
®
RTM20xx
30
User Manual 1317.4726.02 ─ 01
Coupling
Selects the connection of the input signal. The current coupling of each channel is shown
in the waveform labels above the grid.
"AC"
A 2 Hz high-pass filter is placed into the signal path that removes the
DC offset voltage from the input signal. AC coupling is labeled with
≈
.
"DC"
DC coupling passes the input signal unchanged. It is labeled with
≅
.
"GND"
Connects the input virtually to the ground. All channel data is set to a
constant ground value. Ground connection is labeled with .
Remote command:
Termination
Adjusts the input impedance of the instrument to the impedance of the DUT. By default,
the oscilloscope has an input impedance of 1
MΩ || 13
pF. If an active probe is used, the
termination is read out from the probe - usually it is 50
Ω
.
"50
Ω
"
In measurement systems that are dimensioned for a characteristic
impedance of 50
Ω
, reflections along the signal path are minimized by
setting the input resistor of the oscilloscope also to 50
Ω
. This increases
the accuracy of measurement results. 50
Ω
termination is identified for
each channel by the icon
Ω
in the waveform label.
"1
M
Ω
"
The high input resistor minimizes the loading effect on the device under
test. This value is set automatically if a passive probe is connected and
cannot be changed.
Remote command:
Bandwidth
Selects the bandwidth limit. The specified full bandwidth indicates the range of frequen-
cies that the instrument can acquire and display accurately with less than 3dB attenua-
tion. The probe has also a limited bandwidth and thus affects the resulting system band-
width.
See also:
"Full"
At full bandwidth, all frequencies in the specified range are acquired
and displayed. Full bandwidth is used for most applications.
Reference for Waveform Setup