Tektronix PSM3000 Series, User Manual

Page: 47 / 76

Pulse Pro fi ling Application
5. Click the Zoom In or Zoom Out buttons. These buttons double or halve the
current viewing area. These buttons are available in the Results window and
in the Display Control toolbar.
6. Click the Reset button. This resets the Measurement Trace window to include
the entire Panoramic trace.
7. Use the scroll and nudge controls in the Results window. These controls allow
you to scroll the area of interest left or right. The nudge controls move the
area one small step at a time.
CDF, CCDF, and PDF
Display
You can select to print CDF (Cumulative Distribution Function), CCDF
(Complementary Cumulative Distribution Function), or PDF (Probability Density
Function) displays from the Print toolbar. All displays are printable in black and
white or color (depending on the capabilities of your printer). For all of these
displays, you can set the resolution, data source (trace or gates), minimum and
maximum power, and the number of data sets or runs with counter. (See page 16,
Pulse Pro fi ling .)
The CDF display shows the probability that a signal is below the average power
level.
The CCDF display shows how much time the signal spends at or above the
average power level (expressed in dB relative to the average power). The
percentage of time the signal spends at or above each line de
fi nes the probability
for that particular power level. A CCDF curve is a plot of relative power levels
versus probability.
Power (CCDF) curves provide critical information about the signals encountered
in 3G systems. These curves also provide the peak-to-average power (crest factor)
data needed by component designers.
The PDF shows the distribution of the average power level.
NOTE.
Read more about the Print toolbar. (See page 46, Print.)
RF and Microwave Power Sensors/Meters 33