NI PXIe-5694 Calibration Procedure
|
© National Instruments
|
35
7.
Configure RF source 1 as follows:
•
Single frequency mode
•
Frequency: 193.6 MHz
•
Power level: -6 dBm
8.
Configure the power meter as follows:
•
Channel 1: Power sensor A
•
Trigger with settling delay
•
Sensor setting: 0.1%
9.
Configure the digitizer as follows:
•
Sampling rate: 585.9375 kS/s
•
Number of samples to acquire: 40,960
•
Reference source: PXI_Clk
•
Reference Clock rate: 100 MHz
•
DDC enabled: TRUE
•
Data processing mode: Complex
•
Frequency translation enabled: TRUE
•
DDC center frequency: 193.6 MHz
•
Dither enabled: FALSE
•
Bandpass filter enabled: TRUE
10. Set the NI 5694 IF filter to 20 MHz.
11. Read the power meter channel A power.
12. Calculate the NI 5694
IF input power
using the following equation:
IF Input Power
=
Channel A Power
+
Splitter Tracking at 193.6 MHz
13. Set IF Attenuation Table Index to 0.
14. Acquire a record of complex samples with the NI 5622 digitizer and compute the
digitizer
power
in dBm
using the following equation:
where:
N
= Number of samples to acquire
I
j
= Real part of the
j
th complex sample
Q
j
= Imaginary part of the
j
th complex sample
15. Query the NI 5622
digitizer frequency response
and retrieve the value at 193.6 MHz by
linear interpolation.
Digitizer Power
10
log
10
×
1
N
----
I
j
2
Q
j
2
+
(
)
j
0
=
N
1
–
10
+
=
