Boonton 52000 Series USB CW Power Sensor - Manual (Page 31)

Boonton 52000 Series 1
pulse period
on time
time
pulse power
average
power
duty cycle =
on time
pulse period
100%
1
p.r.f. = pulse period
average power =
on time
pulse power x
x
pulse period
Watts
Figure 2 Typical RF burst
Measuring GSM mobile signals
GSM mobile signals are usually present for a single time-slot per
frame, that is, for approximately one eighth of the time, since there
are eight time slots per frame.
The mobile transmitter is active for slightly less than this time because
the transmitter has around three ‘tail’ bits to ramp up and down in
power, and 8.25 guard bits where the transmitter is silent. This means
that the transmitter is inactive for 11.25 bits out of 156.25.
That is for roughly (156.25 - 11.25) / 156.25 = 0.928 of a time slot.
The duty cycle of the transmitter is then 12.5% * 0.928 = 11.6%.
Refer to Figure 27 on page 32.
Note This measurement example is based on the 51012 sensor.