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INSTRUCTION MANUAL
SECT IO N 6
-
TEST LEVEL CALIBRATION
Rev050321
In the following procedures, instructions are included for both methods.
Instructions common for both
METHOD A
and
METHOD B
are shown in BLACK text.
Any instructions applicable only for
METHOD A are shown in GREEN text.
Any instructions
applicable only for METHOD B are shown in BLUE text.
For each method, as will be discussed later in this chapter, the test generator
equipment is used to inject the test signal via the RF port of the EM Clamp. The test
level is set by measuring the amplitude of the test signal
at the output of the 150Ω
to 50Ω Adapter connected to the EUT port of the
EM Clamp (through a power
attenuator). For each test frequency, the amplitude of the injected RF is adjusted
incrementally until the measured amplitude reaches the appropriate level
(U
mr
)
.
The primary difference between the two methods relates to:
a)
the method with which the test generator output is quantified at each
frequency during calibration when the appropriate test level is achieved;
and,
b)
the method by which the same test generator output level set during
calibration is reproduced at each frequency during actual EUT testing.
METHOD A:
For method A, once the appropriate amplitude is measured at any
given frequency during calibration process, the signal generator
output level is recorded, along with the frequency.
Then, during the test, the signal generator output level at any given
frequency will be set to the respective level that was recorded
during the calibration process.
METHOD B:
For method B, once the appropriate amplitude is measured at any
given test frequency during the calibration process, the forward
power of the test generator and frequency is recorded. The
forward power can be measured with an RF power meter/sensor,
or it can be measured with a spectrum analyzer/EMI receiver. The
measuring instrument is typically connected to the forward port of
a directional coupler installed in series with the drive line, between
the RF output of the power amplifier and the input port of the EM
Clamp.
During the test, the signal generator output level is adjusted so that
the forward power measured on the power meter or spectrum
analyzer/EMI receiver at any given test frequency is equal to the
respective forward power level recorded during the calibration
process.
Distributed by: Reliant EMC LLC, +1 408 916
‐
5750, [email protected], www.reliantemc.com
