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LANGER
DE-01728 Bannewitz
mail@langer-emv.de
EMV-Technik
www.langer-emv.com
1 Usage
1.1 Measurement under interference conditions
Measurement of analog electrical signals under extreme electromagnetic stress such as:
- Coupling of radiated or conducted RF emissions
- Fast transients burst / ESD
- High potential (high voltage)
1.2 EMC tests as the main field of application
- Radiated RF emissions EN 61000-4-3:
80 MHz-1 GHz, 80 % AM (1 kHz), anechoic chambers TEM cells stripline,
- Conducted RF emissions EN 61000-4-6:
40 V
, 150 kHz-230 MHz, 80 % AM (1 kHz)
eff
- Burst EN 61000-4-4
- ESD EN 61000-4-2
1.3 Measured signals
- Supply voltages (switching controllers, linear controllers),
- Reference voltages,
- Digital signals (optical couplers, optical receivers),
- Analog signals (operational amplifiers, ADC, DAC).
1.4 Specific measurement technology
To measure analog signals under extreme interference conditions, measurement technology is
needed that
a) itself is not affected by disturbance fields and thus does not simulate any disturbance in the
equipment under test (DUT),
b) can be connected to the DUT in a decoupled way, i.e. connecting the probe head does not
result in the development of additional disturbance current paths through which disturbances
can penetrate or be discharged.
The A100 / A200 / A300 optical fibre measurement systems meet these demands.
1.5 Specific measuring task
Analog electronic modules are generally influenced in EMC tests when RF, modulated by 1 kHz, is
applied to the DUT. This influence is due to the fact that the infiltrated RF disturbance is demodu-
lated at PN junctions of the electronic circuit. This generates signal level fluctuations or 1 kHz
disturbance signals. The 1 kHz disturbance signal is produced through modulation of the RF
disturbance by 1 kHz.
Relatively slow disturbance signals with a fundamental wave of 1 kHz, which mostly interfere with
analog circuits, are characteristic for RF disturbance coupling.
Figure 1 to Figure 6 on the following pages shows examples of useful signals that were subjected
to disturbances. The deviation of the signal form from the sine wave varies, i.e. the disturbance
signal also contains a harmonic component as well as the fundamental one. The task is to correctly
measure these relatively slow disturbance signals under extreme RF interference conditions.
The A100 / A200 / A300 measurement systems are ideal for these conditions because of their high
disturbance immunity.
A100 / A200 / A300
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