B+K precision RFM3000 Series, Руководство пользователя, Страница: 51 / 58

Application Notes 51
Item dBm mW
Mesial value 10.0 10.0
Sample n 8.0 6.3
Sample n+1 11.0 12.6
Table 5.4 Interpolation Crossing
The interpolated crossing time,
𝑡
𝑥
, is calculated from:
𝑡
𝑥
= 𝑡
𝑛
+
𝑃
𝑚𝑒𝑠
− 𝑃
𝑛
𝑃
𝑛+1
− 𝑃
𝑛
where
𝑃
is in watts and n is the number of the sampling interval, referenced to the trigger event.
For this example:
𝑡
𝑥
= 𝑡
𝑛
+
10.0 − 6.3
12.6 − 6.3
𝑡
𝑥
= 𝑡
𝑛
+ 0.6
11. The processor computes the rise and/or fall times of waveforms that meet the following conditions:
• The waveform must have at least one usable edge (Types 2 through 7).
• The signal peak must be at least 13 dB greater than the minimum sample value.
The rise time is defined as the time between the proximal and distal crossings (– +).
The fall time is defined as the time between the distal and proximal crossings (+ –).
If no samples lie between the proximal and distal values for either edge (rise or fall), the risetime for that edge is set
to 0 seconds.
12. The processor calculates the output values according to the following definitions:
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
k)
l)
m)
n)
Pulse Width
Rise time
Fall time
Period Cycle
Pulse Repetition
Duty Cycle Pulse
Off-time
Peak Power
Pulse Power
Overshoot
Average Power
Top Amplitude
Bottom Amplitude
Skew
Interval between mesial points
See Step 11
See Step 11
time between mesial points
Reciprocal of Period Frequency
Pulse Width/Period
(Period) - (Pulse Width)
Maximum sample value (See Step 1)
Average power in the pulse (between the mesial points)
(Peak Power) - (Top Amplitude)
See Step 13
See Step 8
See Step 7
See Step 14