Radiated EMC test in Tekbox Open TEM Cells

Radiated EMC test in Tekbox Open TEM Cells Door: AR Benelux
Identify
Localize (Near Field)
Validate (Far Field)
Control & Document

 

 

Open TEM Cells &
Shielded Tents & Bags
Near Field Probes &
Amplifiers
Antennas
Spectrum Analyzers &
EMC Software

 

Pre-compliance EMC testing made easy

AR Benelux offers affordable EMC test tools from Rigol and Tekbox that allow anyone to perform in house EMC debugging during the initial product design and pre-certification tests on small EUT or subassemblies before submitting to an official EMC testlab. Following a simple and logic test approach as described below will give you early insight in the EMC performance of you product and helpyou prepare to succesfully pas the official test at the official EMC lab and  avoid costly and time consuming redesigns en re-testing.

Identify

Tekbox offers simple and affordable test tools for precompliant EMC testing. One of these tools are the Tekbox Open TEM cells available in 4 sizes. Radiated Immunity test in the TEM are made possible under EMCview control using the tracking generator of the Rigol Spectrum Analyzers. The tracking generator output is connected by the TBMDA series Modulated Driver Amplifiers that can also apply 1 KHz 80% AM or pulse modulation. The output drives the TEM cell in which Uniform Fields up to tenth’s or even hundred’s Volts per meter can be generated, depending on cell size and amplifier model.

Although TEM cells originally have been designed for radiated immunity they also can be used for (Near Field) Radiated Emission measurements on small DUT’s or subassemblies up to frequenties of over 6 GHz. The Open TEM cell can be placed in a matching Tekbox Shielded Tent or Bag to attenuate ambient noise by up to 50-70 dB. This way emissions produced by the DUT can easily be identified.

Localize

Once immunity sensitive frequencies and/or emission peaks have been identified Near Field Probes can be used to hunt down and localize the source of interference on the DUT down to component or circuit level.  After debugging and applying design improvement the emission can be remeasured and overlayed with the initial scan. This way it is easy to compare before and after results and check if emission peaks lowered indeed and also important if the problem did not move to other frequency (this happens often!).

Validate

Finally quantative emissions measurements in the far field using an antenna can be performer and be validated against limit lines.These final far field measurements provide optimum correlation with with the official measurement methode in an anechoic chamber as performed by  EMC labs.

CISPR 25 and CISPR 14 (for battery powered equipment)  specify radiated emission levels for TEM-cells that can directly can be evaluatie against limit lines as an alternative to far field limits.

Alternatively it is possible to use the EMWware correlation feature as specified in IEC 61000-4-2 to convert measurements in the TEM cell to 3 meter FAR field values.  This requires measurement scans on all 3 axis which are converter by EMCview to Far field values using the algoritm described in the Standard.

 

Informative TekBox FAQ

Download the Tekbox FAQ and read how to perform pre-compliant radiated immunity and emission test in a Open TEM Cell.

  • Which input power do I need to apply to create a certain field strength inside the TEM cell?
  • What is the useful frequency range of a TEM-Cell?
  • How do TEM-cells compare to near-field probes or antennas
  • Open TEM-cells versus closed TEM-cells
  • TEM-cells versus GTEM-cells
  • How to correlate TEM-cell measurements with far field limits
  • How to carry out pre-compliance radiated emission testing with open TEM cells?
  • How to carry out pre-compliance radiated immunity testing with open TEM cells?
  • What is the usable volume of Tekbox TEM Cells?
  • Field distribution in a TEM-cell

QA Tekbox OpenTEM Cells

 

More information

Please visit the Tekbox and Rigol sections our website for more information/