Anritsu ME7840A, Operation And Maintenance Manual, Page: 43 / 126

Chapter 4
Operations, Calibration
4-1
INTRODUCTION
Measurements always include a degree of uncertainty due to imperfec-
tions in the measurement system. The measured value is always a combi-
nation of the actual value plus the systematic measurement errors. Cali-
bration, as it applies to network analysis, characterizes the systematic
measurement errors and subtracts them from the measured value to ob-
tain the actual value. Each of the ME7840A measurements requires a cal-
ibration to account for measurement uncertainties. This chapter de-
scribes the measurement calibration operations of the Model ME7840A
Power Amplifier Test System software.
4-2
OPERATION,
GENERAL
Refer to Chapter 3 for general operation and setup of the ME7840A.
4-3
PROGRAM FILES
The PATS software sets up the MS462XC DRA Scorpion according to in-
structions in the “Calibration Specification” files, which are accessed from
the “Tools,” “Run Calibration Procedure” function that is described later
in this chapter. These are user-editable text files that establish the condi-
tions during calibration and measurement. How to edit these files is de-
scribed in Appendix A.
The calibration data and Scorpion switch settings that result from follow-
ing a “Run Calibration Procedure” specification file are saved as a *.cal
file. These *.cal files are accessed using the “Tools,” “Calibration File Op-
tion” function that was described in paragraph 3-6, page 3-8. When one
of these files is recalled using the “Calibration File Option,” the Scorpion
is ready to acquire correct (calibrated) measurements.
Examples of instrument settings / conditions that reside in the Calibra-
tion Specification files include:
q Sweep start and stop frequencies
q Number of data points
q Source 1 and 2 power levels
q Scorpion IF bandwidth
q Averaging
q Scorpion display settings
Some of these parameters can also be specified / modified by the User In-
put window before each actual measurement so long as such modification
is consistent with the calibration to be applied.
ME7840A POM 4-1