PMX40 RF Power Meter – INSTRUCTION MANUAL
5-10
11.
The processor computes the rise and/or fall times of waveforms that meet the following
conditions:
a)
The waveform must have at least one usable edge (Types 2 through 7).
b)
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)
Pulse Width
Interval between mesial points
b)
Rise time
See Step 11
c)
Fall time
See Step 11
d)
Period
Cycle time between mesial points
e)
Pulse Repetition Reciprocal of Period Frequency
f)
Duty Cycle
Pulse Width/Period
g)
Off-time
(Period) - (Pulse Width)
h)
Peak Power
Maximum sample value (See Step 1)
i)
Pulse Power
Average power in the pulse (between the mesial points)
j)
Overshoot
(Peak Power) - (Top Amplitude)
k)
Average Power See Step 13
l)
Top Amplitude
See Step 8
m)
Bottom Amplitude See Step 7
n)
Skew
See Step 14
5.3.4
Average Power Over an Interval
13.
The average power of the signal over a time interval is computed by:
a)
summing the sample powers in the interval
b)
dividing the sum by the number of samples
This process calculates Pulse Power, Average Power, and the average power between markers.
Since each sample represents the power in a finite time interval, the endpoints are handled separately
to avoid spreading the interval by one-half pixel at each end of the interval (see Figure 5-7). For the
interval in Figure 5-7, the average power is given by:
𝑃𝑃
𝑎𝑎𝛼𝛼𝑎𝑎
=
1
2
(
𝑃𝑃
0
+
𝑃𝑃
𝑛𝑛
) +
1
(
𝑛𝑛 −
1)
� 𝑃𝑃
𝑛𝑛
𝑛𝑛−1
𝑛𝑛=1
