Bird Technologies SA-6000EX - Manual (Page 127)

Measure Power Mode
111
Peak Envelope Power
Peak power measurements detect amplitude changes as a signal mod-
ulates the carrier envelope. The WPS operates in an asynchronous
cycle: 300 ms of waveform sampling followed by a 50 ms reset period.
The peak power is then displayed and the cycle repeats. The display
therefore updates about three times per second.
Burst Average Power
Burst width (BW) is the duration of a pulse. Period (P) is the time
from the start of one pulse to the start of the next pulse. Duty cycle (D)
is the percentage of time that the transmitter is on. To calculate the
duty cycle simply divide the burst width by the period (D = BW / P).
Low duty cycles mean that the burst width is much less than the
period; a large amount of dead time surrounds each burst. For low
duty cycles, the burst average power will be much larger than the
average power.
After peak power is measured, a threshold of ½ the peak is set. The
sampled power crosses that threshold at the beginning and end of
each burst. The time between crossings is used to calculate the duty
cycle. Burst Average Power is calculated by dividing the Average
Power by the Duty Cycle.
Burst Average
Power
Average Power
Burst Average Power
Peak Envelope Power
0 W
100 W
50 W
Burst Width
Period