Technical data

5-5
Operating Concepts
Sweep Time
• port coupling
By uncoupling the channel powers, you effectively have two separate sources. Uncoupling the test ports
allows you to have different power levels on each port.
Channel coupling
CH PWR [COUPLED], toggles between coupled and uncoupled channel power. With the channel power
coupled, the power levels are the same on each channel. With the channel power uncoupled, you can set
different power levels for each channel. For the channel power to be uncoupled, the other channel
stimulus functions must also be uncoupled (COUPLED CH OFF,).
Test port coupling
PORT PWR [COUPLED], toggles between coupled and uncoupled test ports. With the test ports coupled,
the power level is the same at each port. With the ports uncoupled, you can set a different power level at
each port. This can be useful, for example, if you want to simultaneously perform a gain and reverse
isolation measurement on a high-gain amplifier using the dual channel mode to display the results. In this
case, you would want the power in the forward direction (S
21
) much lower than the power in the reverse
direction (S
12
).
Sweep Time
The SWEEP TIME [ ], softkey selects sweep time as the active entry and shows whether the automatic or
manual mode is active. The following explains the difference between automatic and manual sweep time:
• Manual sweep time. As long as the selected sweep speed is within the capability of the instrument, it
will remain fixed, regardless of changes to other measurement parameters. If you change measurement
parameters such that the instrument can no longer maintain the selected sweep time, the analyzer will
change to the fastest sweep time possible.
• Auto sweep time. Auto sweep time continuously maintains the fastest sweep speed possible with the
selected measurement parameters.
Sweep time refers only to the time that the instrument is sweeping and taking data, and does not include
the time required for internal processing of the data, retrace time, or band switching time. A sweep speed
indicator
↑ is displayed on the trace for sweep times longer than 1.0 second. For sweep times equal to or
faster than 1.0 second, the
↑ indicator appears in the status notations area at the left of the analyzer's
display.
Manual Sweep Time Mode
When this mode is active, the softkey label reads SWEEP TIME [MANUAL]. This mode is engaged
whenever you enter a sweep time greater than zero. This mode allows you to select a fixed sweep time. If
you change the measurement parameters such that the current sweep time is no longer possible, the
analyzer will automatically increase to the next fastest sweep time possible. If the measurement
parameters are changed such that a faster sweep time is possible, the analyzer will not alter the sweep time
while in this mode.
Auto Sweep Time Mode
When this mode is active, the softkey label reads SWEEP TIME [AUTO]. This mode is engaged whenever
you enter 0, x1, as a sweep time. Auto sweep time continuously maintains the fastest sweep time possible
with the selected measurement parameters.