7-19
Operating Concepts
Sweep Types
Setting Segment IF Bandwidth
To enable the function, you must first select in
the edit subsweep menu. List IF bandwidth is off by default and the asterisks that appear
in the "IFBW" column of the list table indicate that the IF bandwidth for the sweep is
being set by the normal analyzer controls.
Narrow IF bandwidths require more data samples per point and thus slow down the
measurement time. Selectable IF bandwidths can increase the throughput of the
measurement by allowing you to specify narrow bandwidths only where needed.
Power Sweep (dBm)
The softkey turns on a power sweep mode that is used to characterize
power-sensitive circuits. In this mode, power is swept at a single frequency, from a start
power value to a stop power value, selected using the and keys and the
entry block. This feature is convenient for such measurements as gain compression or AGC
(automatic gain control) slope. To set the frequency of the power sweep, use in
the stimulus menu.
The span of the swept power is limited to being equal to or within one of the eight
pre-defined power ranges. The attenuator will not switch to a different power range while
in the power sweep mode. Therefore, when performing a power sweep, power range
selection will automatically switch to the manual mode.
In power sweep, the entered sweep time may be automatically changed if it is less than the
minimum required for the current configuration (number of points, IF bandwidth,
averaging, etc.).
CW Time Sweep (Seconds)
The softkey turns on a sweep mode similar to an oscilloscope. The analyzer is
set to a single frequency, and the data is displayed versus time. The frequency of the CW
time sweep is set with in the stimulus menu. In this sweep mode, the data is
continuously sampled at precise, uniform time intervals determined by the sweep time and
the number of points minus 1. The entered sweep time may be automatically changed if it
is less than the minimum required for the current instrument configuration.
In time domain using Option 010, the CW time mode data is translated to frequency
domain, and the x-axis becomes frequency. In this mode, the instrument can be used as a
spectrum analyzer to measure signal purity, or for low frequency (<1 kHz) analysis of
amplitude or pulse modulation signals.
Selecting Sweep Modes
In addition to the previous sweep types, there are also two different sweep modes. These
can be accessed through the correction menu by pressing
or .
SEGMENT IF BW
LIST IF BW ON off
POWER SWEEP
Start Stop
CW FREQ
CW TIME
CW FREQ
Cal
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ALTERNATE A and B