CWS500C

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CWS500C
RF Conducted Immunity Testing
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E-fields and/or H-fields
Radiated Fields
Conducted
Power Mains
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POTENTIAL DISTURBANCES

• Electromagnetic disturbances coming from intended
  radio-frequency (RF) transmitters (E and H
  fields)such as

• Transmitters fixed-station radio and
  television transmitters small hand-held
  (portable) radio transceivers (walkie-talkies)
  vehicle radio transmitters and broad cast
  transmitters

• Traffic rail, aircraft and road vehicle
  ignition systems

• Industry various industrial electromagnetic
  sources like welders, thyristors fluorescent
  lights, switches operating inductive loads etc.

• Power distribution power line currents and
  return leakage currents in the earthling/
  grounding system and corona discharges

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RF Conducted Immunity Test Application

• Relevant Standards
• IEC/EN 61000-4-6
• EN 50082-1/2
• EN 61000-6-2
• MIL-STD-461E CS114
• DO 160D, BCI
• ISO 11452-1,3,4,5

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PURPOSE AND DEFINITION

• Injection of a controlled level of radio
  frequency (RF) voltage on to interconnecting
  cables

• The voltage is derived from a voltage source
  with 150 ? source impedance

• The voltage generator shall provide both
  continuous wave (CW) and modulated signals

• The RF disturbance is feed into a load (EUT)
  along cable with a common-mode impedance of
  150 ?. The common- mode impedance is the
  combined parallel impedance of all conductors
  of that cable with respect to ground

• The RF disturbance is fed into the EUT by a
  coupling device such as coupling/decoupling
  network (CDN) or injection clamp (EM clamp or
  current injection clamp)

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RF Conducted Immunity Test Application
IEC 61000-4-6 Test Requirements
Level Test voltage Frequency range
Amp. modulation V
1 1.0 2
3.0 150kHz - 80MHz 80 AM
with 1kHz 3 10 x
special
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RF Conducted Immunity Test Application
Injection Methods

• CDN
• Direct Coupling
• Clamp injection
• EM clamp
• Current clamp
• Observe clamp injection guidance in para. 7.2
  7.3

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Conducted Immunity Test Application
Injection methods
Is a CDN suitable for particular cable?
then a CDN should be used
yes
no
then use the EM clamp and make provisions to
ensure repeatability
Is the EM clampsuitable for use?
yes
no
otherwise use current injection clamp (BCI) and
make provisions to ensure repeatability
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Coupling/decoupling networks
CDNs come in several formats depending on the
kinds ofcable they are used with. Particular
types include

• Supply These are normally designed M1, M2, M3,
  M5 depending on the number of connectors that
  are usually bundled together in the supply cable.

• Audio frequency These are unscreened
  non-balanced lines and the CDNs are
  designated AF2, AF4 depending on the numbers of
  connectors.

• Twisted Pair These are unscreened balanced pair
  cables and the CDNs are designated T2, T4
  depending on the number of connectors. The
  coupling and decoupling circuits can be more
  complex for these kinds of CDN because of the
  differential signal on the balanced lines.

• Screened cables Where the cable to be tested is
  not a screened cable, the interfering RF signal
  is injected equally to each conductor in the
  cable. For special case of screened cables the
  RF is injected directly on the screen via 100 ?
  resistor, leaving the other (screened) conductors
  alone.Special types of CDN, denoted S1, S2 are
  used for screened cables.

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Application Information
According to the standard there are two parts to
performing the RF Conducted Immunity test

• The calibration phase to level the voltage
  across the 150 ohm common mode impedance for all
  tested frequencies

• The test phase where the leveled voltage is
  applied to the EUT via the coupling method chosen

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CW and amplitude modulated injection signals
Unmodulated CW signal for Test
signal 80 AM superimposed calibration
purposes (consistency) on the RF carrier
Ucc 2.8V, Urms 1.0V Ucc
5.1V , Urms 1.15V
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Sweep rate
According to the standard there are two kind of
sweep possibilities

• Smoothing sweep of which the rate must not
  exceed 0.0015 decades per second. At this rate,
  it takes 30 minutes to sweep from 150
  kHz to 80 MHz.

• Discrete frequency sweep with 1 steps. This
  will result in 232 steps per decade or a total
  of 633 frequencies. A dwell time of 2.9 seconds
  at each frequency will comply with the standard,
  also taking 30 minutes.

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Conducted Immunity Test Equipment
CWS 500C 9kHz - 250MHz with internal Signal
Generator and Calibration/Monitor Power
Meters Tests using CDNs EM
Clamp Current Clamp ICD Software with
Vector feature for control, measurement and
reporting
IEC 61000-4-6 IEC 61000-6-1 2 IEC 60601-1-2 EN
50082
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Conducted Immunity Test Equipment
CWS 500D 9kHz - 400MHz with internal Signal
Generator, Amplifier, Directional Coupler Tests
using CDNs EM Clamp Current
Clamp ICD Software with Vector feature
for control, measurement and reporting
ISO 11452-3 TEM CELL ISO 11452-4,5 BCI SAE
J1113-4 MIL-STD-461E CS114 DO 160D, BCI
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CWS500C Block Diagram
Cal In
Monitor In
Calibration
Monitor
Control
Generator
Attenuator
75 W Amplifier
RS232
IEEE 488
RF Out
Fail 1/2
Display
Keyboard
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CWS500D Block Diagram
Cal In
Directional Coupler
Forward Power
Calibration
Control
Generator
Attenuator
75 W Amplifier 10KHz-400MHz
RS232
IEEE 488
Fail 1/2
Display
Keyboard
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Calibration set up when using CDNs
Determining the RF voltage transfer
characteristic-voltage leveling over the swept
frequency range
Cal-Input
Insulating Material
)
(50
W
W
W
150
to 50
Adapter
30mm
T2
CWS500
CDN
100
W
AE
6dB
30mm
Ground reference plane
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CDN Transfer characteristic example
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The recommended test set up when using CDNs.
Non-Tested Cable
Cable under test
EUT
50
W
CWS 500
AE
100mm
T2
CDN
CDN
AE
6dB
30mm
Ground reference plane
Insulating support
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Calibration set up when using EM clamp
Determining the RF voltage transfer
characteristic-voltage leveling over the swept
frequency range
T2
HF OUT
(CWS500)
6dB
30mm
W
100
100
W
CAL INPUT
W
(150
to
(150
W
to
W
50
(CWS500)
W
50
50
W
30mm
Adapter)
Adapter)
Ground reference plane
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Calibration set up when using current clamp
Determining the RF voltage transfer
characteristic-voltage leveling over the swept
frequency range
T2
HF OUT
(CWS500)
6dB
Current injection clamp
30mm
W
100
100
W
CAL INPUT
W
(150
to
(150
W
to
W
50
(CWS500)
W
50
50
W
30mm
Adapter)
Adapter)
Jig
Ground reference plane
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CWS500C Application
BCI calibration setup with internal power meter
IEEE 488
6dB
CWS cal Input
100R
100R
50R
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CWS500C set up when using current injection clamp
Non-tested Cable
Cable under test
EUT
Measuringclamp
50
W
CWS 500
100mm
T2
CDN
AE
6dB
AE
30mm
Injection clamp
Insulating support
Ground reference plane
Measuring equipment
Imax Uo/150?