Tektronix PSM3000 Series, User Manual

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Pulse Pro fi ling Application
Fall Time (FT).
Returns the time required for the signal to decrease in amplitude
from 90% to 10% of the amplitude as de fi ned by the placement of the left-most
gate. The right gate de fi nes the end of data for this measurement.
Pulse Width (PW).
Returns the pulse width in μ s. The width of the pulse is the
time for a signal to rise to within 3 dB of the top of the pulse, and then fall 3 dB
below the top of the pulse. The left-most gate de
fi nes the start of data and must
precede a positive going edge. The right-most gate de fi nes the end of data and
must follow one or more subsequent falling edges.
Pulse Repetition Time (PRT). Returns the PRT in μ s. The PRT is the time between
the fi rst rising edge and the second rising edge. The gates for this measurement
must include at least one complete, uninterrupted cycle. The left-most gate must
follow a positive going edge and the right-most gate must precede one or more
subsequent falling edges and at least one rising edge.
Pulse Repetition Frequency (PRF).
Returns the PRF in Hz or kHz. The PRF is the
inverse of the time (1/PRT) between the rising edges of two successive pulses.
The pulse edges are de
fi ned by the pulse peak criteria. This measurement can be
limited by the threshold value. The gates for this type of measurement must be
positioned with the same restrictions as the PRT measurement.
Duty Cycle (DC).
Returns the percentage of on time during a selected cycle. The
gates for a duty cycle measurement must be positioned with the same restrictions
as the PRT and PRF measurements. The measurement then proceeds to sort all
samples into one of two bins. One bin is the “ON” bin and the other bin is the
“OFF” bin. All points within 3 dB of the pulse top are placed in the “ON” bin. All
other samples are placed in the “OFF” bin. Then a simple calculation is done:
DC (Duty Cycle) = #ON samples / (#ON s #OFF samples)
Pulse Power (Pls).
Returns the average power between the rising and falling
edges of the fi rst complete pulses in dBm. The gate must be positioned exactly
like PW measurements. The average of all samples between the rising and falling
edges is reported. The pulse edges are de
fi ned by the pulse peak criteria. This
measurement can be limited by the threshold value.
Peak Power (Pk).
Returns the highest power level between two gates. There is
no requirement for a rising or falling edge anywhere within the measurement
window as de
fi ned by the gates.
Average Power (Avg).
Returns the average power between two gates. There is
no requirement for a rising or falling edge anywhere within the measurement
window as de
fi ned by the gates.
Crest Factor (CF or CrF). Returns the difference between the peak power and
average power in dB. There is no requirement for a rising or falling edge anywhere
within the measurement window as de
fi ned by the gates.
RF and Microwave Power Sensors/Meters 43