Difference between revisions of "IEC 61000-4-20"
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* It is advised to not use EUT that are larger than 1/3 of the height of the usable height of the TEM. | * It is advised to not use EUT that are larger than 1/3 of the height of the usable height of the TEM. | ||
* For the [[Immunity]] testing, the standard describes that the Uniform Field Area in the TEM should be verified, using the procedures similar to as described in the [[EN 61000-4-3]]. | * For the [[Immunity]] testing, the standard describes that the Uniform Field Area in the TEM should be verified, using the procedures similar to as described in the [[EN 61000-4-3]]. | ||
+ | |||
+ | |||
+ | == Emission == | ||
+ | The TEM cell is a different and cost efficient method, compared to the [[OATS]], to measure the emission patron of the [[EUT]]. This method does have a down side, calculation is needed to correlate the measurements done in the TEM cell to the [[OATS]] | ||
+ | |||
+ | For the emission tests there are 2 ways to calculate a correlation to the OATS: | ||
+ | # multi pole model | ||
+ | # three voltage measurements | ||
+ | |||
+ | === Multi pole model === | ||
+ | The multi pole model is currently not supported by {{radimation}} | ||
+ | |||
+ | === Voltage measurements: 3-Positions === | ||
+ | Also known as the "To Radiated Power method". In this method the EUT is placed in 3 axis (x, y and z). | ||
+ | |||
+ | <math>S=\sqrt{ V_{x}^2 + V_{y}^2 + V_{z}^2 }</math> | ||
+ | |||
+ | <math>V_{x}</math>, <math>V_{y}</math> and <math>V_{z}</math> are the measurements done in Volt on the same frequency but in different directions. | ||
+ | |||
+ | <math>S</math> is the Root-sum-square of the measured voltages. | ||
+ | |||
+ | <math>E_{max}=G_{max} * \sqrt{ \frac{3\eta_0}{4\pi} P_0 } </math> | ||
+ | |||
+ | <math>E_{max}</math> is the maximum field in V/m | ||
+ | |||
+ | <math>\eta_0=\sqrt{ \frac{\mu_0}{\epsilon_0} } = 120\pi\Omega = 377 \Omega</math> | ||
+ | |||
+ | <math>G_{max}</math> is the geometry factor determined by the height scan of the receiving antenna. | ||
== Related standards == | == Related standards == |
Revision as of 13:16, 28 January 2022
The EN/IEC 61000-4-20 standard describes how Immunity and Emission measurements are performed in a transverse electromagnetic (TEM) waveguides.
The exact title of this standard is: "IEC 61000-4-20: Electromagnetic compatibility (EMC) - Part 4-20: Testing and measurement techniques - Emission and immunity testing in transverse electromagnetic (TEM) waveguides"
This review is based on the Edition 2.0 2010-08 version.
Some random remarks and notes:
- It is advised to not use EUT that are larger than 1/3 of the height of the usable height of the TEM.
- For the Immunity testing, the standard describes that the Uniform Field Area in the TEM should be verified, using the procedures similar to as described in the EN 61000-4-3.
Contents
Emission
The TEM cell is a different and cost efficient method, compared to the OATS, to measure the emission patron of the EUT. This method does have a down side, calculation is needed to correlate the measurements done in the TEM cell to the OATS
For the emission tests there are 2 ways to calculate a correlation to the OATS:
- multi pole model
- three voltage measurements
Multi pole model
The multi pole model is currently not supported by RadiMation®
Voltage measurements: 3-Positions
Also known as the "To Radiated Power method". In this method the EUT is placed in 3 axis (x, y and z).
, and are the measurements done in Volt on the same frequency but in different directions.
is the Root-sum-square of the measured voltages.
is the maximum field in V/m
is the geometry factor determined by the height scan of the receiving antenna.