EM TEST (Switzerland) GmbH
CWS500 N1.3 / N1.4
User manual
V 1.01
41 / 47
9.7.
6dB Attenuator
The 6dB attenuator is connected directly to the RF-output of the
CWS 500N1.x The attenuator matches the output to a 50
system.
The attenuator must be connected as close as possible to the
coupling/decoupling network (CDN, EM clamp or current injection
clamp), using a 50cm (20 inch) coaxial cable.
Fig 8.5 : ATT 6/80
The attenuator has an N-connector at the CWS 500N1.x side and a BNC connector at the CDN output.
The attenuator is required in the actual standard. However, the included amplifier will work correctly with any
load.
9.8.
CDN Coupling/ Decoupling Network
The CDN’s are connecting externally to the output of the 6dB-
attenuator. The coupling network is use to couple the interference to
the lines of the equipment under test. The coupling accomplished
with capacitors or resistors having a sufficient bandwidth according
to IEC 61000-4-6.
The components, the common mode impedance and the coupling
factor specified within the standard.
Fig 8.6 : CDN M5
Fig 8.7 : Typical Impedance Zce of a CDN
Fig 8.8. : Typical insertion loss of a CDN
Impedande values as per IED 61000-4-6 Ed. 4
0.15 MHz
– 24 MHz
150 Ohm +/- 20 Ohm
24 MHz
– 80 MHz
150 Ohm +60/- 45 Ohm
80 MHz
– 230MHz
150 Ohm +/- 60 Ohm (informative according Annex B for tests >80MHz)
Examples of a single shielded line (S1) and a 3-line power supply (M3) are shown below.
Fig 8.9 : CDN S1
Fig 8.10 : CDN M3
