Keysight 90000 X Series Service Manual page 39

11 Change the generator frequency to the maximum value for the model being tested as
shown in the table below. It is not necessary to adjust the signal amplitude at this
point in the procedure.
Setting
MSO/DSO/DSAX
91304A
Maximum 13 GHz
Frequency
Scope Time 50 ps/div
Base Setting
MSO/DSO/DSAX
92804A
Maximum 28 GHz
Frequency
Scope Time 50 ps/div
Base Setting
12 Change the scope time base to the value for the model under test in the table above.
Click here and enter time
base value from table
13 Measure the input power to the scope channel at the maximum frequency and convert
this measurement to Volts RMS using the expression:
V = P
in meas
For example, if the power meter reading is 4.0 μW, then Vin = (4.0*10
14.1 mVrms.
Record the RMS voltage in the Analog Bandwidth - Maximum Frequency Check section
of the Performance Test Record (Vin @ Max Freq).
14 Press [Clear Display] on the scope and record the scope V rms reading in the Analog
Bandwidth - Maximum Frequency Check section of the Performance Test Record (Vout
@ Max Freq).
15 Calculate the gain at the maximum frequency using the expression:
Gain
Max Freq
For example, if (Vout @ Max Frequency) = 13.825 mV, (Vin @ Max Frequency) = 13.461
mV and Gain @ 50MHz = 1.0023, then:
Gain
Max Freq
Record this value in the Calculated Gain @Max Freq column in the Analog Bandwidth
- Maximum Frequency Check section of the Performance Test Record. To pass this test,
this value must be greater than - 3.0 dB.
MSO/DSO/DSAX
91604A
16 GHz
50 ps/div
DSO/DSA 93004L
30 GHz
50 ps/div
×
50Ω
(
V
out Max Freq
------------------------------------------------------------------------------
= 20 log
10
13.825 mV 13.461 mV
-------------------------------------------------------------
= 20 log
10
Chapter 3: Testing Performance
Analog Bandwidth -- Maximum Frequency Test
Model
MSO/DSO/DSAX
92004A
20 GHz
50 ps/div
Model
MSO/DSO/DSAX
93204A
32 GHz
50 ps/div
) ⁄ (
V
in Max Freq
Gain
50 MHz
⁄
= 0.212 dB
1.0023
MSO/DSO/DSAX
92504A
25 GHz
50 ps/div
- 6 1/2
* 50Ω) =
)
39