2
Testing Performance
58
9 Change the signal generator output frequency according to
the maximum frequency for the oscilloscope using the
following:
•
1 GHz Models: 1 GHz
•
500 MHz Models: 500 MHz
•
300 MHz Models: 300 MHz
•
100 MHz Models: 100 MHz
10 Referencing the frequency from step 9, set the power meter
Cal Factor % to the frequency value on the calibration chart
on the power sensor.
11 Set the oscilloscope sweep speed according to the following:
•
1 GHz Models: 500 ps/div
•
500 MHz Models: 1 ns/div
•
300 MHz Models: 2 ns/div
•
100 MHz Models: 5 ns/div
12 Note the oscilloscope Std Dev(1) reading at the bottom of the
screen.
13 Note the reading on the power meter and covert to Vrms
using the expression:
Vin
max_freq
14 Calculate the response using the expression:
response(dB) = 20 log
Example
If:
Pmeas
1_MHz
Std Dev(n)
Pmeas
max_freq
Std Dev(n)
Then after converting the values from the power meter to Vrms:
response(dB) = 20 log
=
Pmeas
max freq
⎡
Vout
⎢
10
⎣
= 892 uW
= 210.4 mV
1MHz
= 687 uW
= 161.6 mV
max freq
⎡
161.6
⎢ ⎣
10
210.4
×
Ω
50
/
Vin
max
freq
max
Vout
/
Vin
1
MHz
1
MHz
⎤
mV
/
185.3
mV
= -1.16 dB
⎥ ⎦
mV/
211.2
mV
⎤
freq
⎥
⎦
Service Guide