Tektronix PSM3000 Series, User Manual

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Power Meter Application
Burst Measurements The PSM4000 and PSM5000 series instruments allow you to make measurements
on RF bursts. To access this measurement, select
Burst Measurement... from the
Measurement drop down menu. From the window that appears, you can specify a
trigger, a delay relative to the trigger, and the sweep time over which the power
measurement is taken. The instrument will then display the peak power, average
power, and minimum power measured during the quali
fi ed duration.
Figure 2: Diagram of a burst time slot
Trigger. The measurement can be triggered by the incoming RF signal, or from
an external TTL source. When using the Internal Auto Level setting, the trigger
level is automatically set to approximately half the pulse amplitude.
Delay.
The delay time determines how long after the trigger the sweep time
begins.
Sweep Time. The sweep time de fi nes the duration of the measurement.
Resolution.
The power measurement data is taken at the real-time sample rate of
the instrument, which is 500 kS/s. This results in a fi xed resolution of 2 μ s.
Measure. The measurements consist of peak power, average power, and minimum
power observed during the speci fi ed sweep time. Measurements can be set to
update continuously by selecting the Continuous check box. Deselect the check
box to stop taking measurements. For a single set of measurements, click on the
Start button. The Copy button transfers the three measurements to the clipboard
so you can paste them into a document.
Data Logging.
Burst measurements can be logged to a text fi le. To do this, type in
or browse to a fi le, and then enable logging by selecting the Log Measurements
check box.
Meas Update Rate
The measurement update rate determines how quickly measurements are updated.
Options are Slowest, Slow, Medium, Fast, and Fastest.
This function is found in the Measurement drop down menu.
RF and Microwave Power Sensors/Meters 23