EMC measurement chain checks & uncertainties

Goals

formation-objectifs-seointro EMC measurement chain checks & uncertainties :

- Propose, implement and monitor measurement chains for EMC validation and investigation tests, mastering all links in the chain, including antennas, amplifiers, measurement sites and device settings in accordance with standards or specific requirements

The aim of this training course is to:
- Know how to measure/verify the characteristics of antennas used in EMC
- Know how to measure/verify the characteristics of transducers used in EMC
- Know how to identify and resolve frequency and time-related difficulties, noise effects, non-linearities and all sources of error that determine measurement uncertainties
- Design protocols for validating measurement chains and measurement software in EMC
- Master the evaluation of measurement uncertainties in EMC tests in order to draft the documents required by standards

Program

1/ Reminder of measurement chain parameters

Document references: CISPR 16 XXX standards

Spectrum analysers: Noise factor, dynamics, detectors, RBW filters, etc. Measurement receiver: Noise factor, dynamics, detectors, RBW filters Preamplifiers: Bandwidth, noise factor, noise temperature, non-linearities

Matching parameters: ROS, RL, S11, S22

Transmission parameters: Gain/loss, S21, S12

Reminder on RF & EMC non-linearities Harmonics, intermodulations

Antennas: Gain, antenna factor, impedance, radiation pattern…

Cables: Attenuation, impedance, transfer impedance Signal synthesizers: Frequency, level, phase noise, modulation Power amplifiers: Bandwidth, harmonic distortion, intermodulation

Faraday cage: Standardised site attenuation, shielding effectiveness

Free space measurement site: Standardised site attenuation



2/ Measurement chain verification equipment

Frequency standards

Standard attenuators / coaxial loads

Synthesised signal generators

Spectrum analysers

Measurement receivers

Spectrum analyser tracking generators

Network or vector analysers

Diode wattmeters, bolometers.

Free space measurement sites.

Tunable dipole antennas

Field calibrators

Sources for inter-laboratory comparisons

3/ Measurement chain verification procedures

Document references ; Standardisation

Validation of EMC measurement and test software

Verification of conducted disturbance sensors

Verification of R.S.I.L

Verification of coupling/decoupling networks

Verification of current probes

Calculation of a current sensor with a cut-off torus

Verification of voltage probes

Distinguo: Transfer function and insertion loss

Verification of filters and decoupling networks

Verification of directional couplers

Verification of preamplifiers

Points ofof the 2nd and 3rd order

Distortion product amplitudes

3rd order intermodulation products

Practical measurement of PI2 and PI3

2-tone method

Calculation ofVerification of broadband power amplifiers Verification of cables and connectors Verification/calibration of antennas Verification ofnormalised attenuation of measurement sites

Verification of Faraday cages

Verification of mode-mixing Faraday cages

Measurement of cable reduction effect; transfer impedance, shielding effectiveness

4/ Measurement uncertainties

Terminology reminders

Guide for expressing uncertainty GUM

Reminders of statistics and probabilities

Analysis of sources of uncertainty in EMC

Uncertainties related to ROS

Maximum measurement error

ROS and reflection coefficient (RL)

Power loss due to ROS / RL

Uncertainties of a calibration

Law of propagation of uncertainty

Standard/composite/extended uncertainty

Evaluation of measurement uncertainties in conducted disturbances

Evaluation of measurement uncertainties in radiated disturbances

&Evaluation of measurement uncertainties in conducted immunity

Evaluation of measurement uncertainties in radiated immunity

Interlaboratory comparison tests

Judgement criteria: the 4 cases

5/ Accessories, auxiliary equipment, tips

Free software for impedance matching

Free software for filtering

Use of LTspice: MC/Mdiff conversion

Measurement problems with RSIL

Single-phase MC/MD separator

Measuring ground noise

Practical measurement of line impedance

Choosing coaxial connectors

Building a current probe with a cut-off toroid

Building directional couplers

Building very wideband 1/10 probes

Building surge arresters

Building an active E-field antenna

Building a power attenuator

Transfer impedance / measurement

Pair imbalance measurement

Directional coupler / Verification

Vector analyser (network)

Insertion loss / S parameters

ROS improvement using an attenuator

Shielding attenuation measurement with a radio receiver on a USB stick

Shielding attenuation measurement with a harmonic generator

Shielding attenuation measurement with a smartphone

Quick modulation verification with the AdalmPluto tool

Other IEC coupling networks

RSIL 5μH aeronautical

Smartphone applications for RF & EMC

6/ Precautions for human exposure

Human exposure to LF induced currents

Human exposure to LF electric fields

Exposure to LF magnetic induction

Summary of action levels

Biological effect of a brief pulse

7/ Conclusions

Summary of relevant websites

Summary of useful software

Bibliography