Posted by Jean-Marc

REVERBERATION CHAMBER – STRONG FIELDS TESTS

02 July 2015

 Brasseur CRBM

Automotive qualifications

  • B217110 indice C and B217110 indice D_test EQ/IR06 until 600V/m
  • GMW3097 Reverberation Chamber Test, Mode Tuning, 3.4.3 until 600V/m
  • Ford CS 2009.1 RI114 band 4, 5, 6, and 7 until 600V/m

 

International standards

  • EN61000-4-21, IEC61000-4-21 and ISO 11452-11  

 

Military, aeronautic and space specifications

  • RCTA DO-160-D and RCTA DO-160-E
  • MILSTD, …
 
 

About the reverberation chamber

 

The reverberation chambers are composed with a shielded enclosure in which the properties of cavities oversized apply. 
The conditions provided by the reverberation chambers provide the equipment under test a statistically isotropic character that avoids redirecting. Moreover, to the extent that the cavity resonance modes are operated, the generation of high fields is provided by injecting relatively low power.

The mode stirrer is composed with metallic pale fixed on a pivoting axis. By changing the angle of the stirrer, a change is applied on the limit conditions that are used to shift the appearance of resonance frequency modes. Thus, since the mode density is high enough, the reverberation chamber can resonate some or the excitation frequency. A second property of the stirring patterns is that it renders the statistically isotropic and homogeneous field on brewer's revolution. This means that a stirrer revolution, the maximum value of the electromagnetic field is almost identical in every room and in all directions.

 

Stirring mode step by step or​ "stirring" 

This stirring mode is realized by a sequential rotation of the stirring on 360°. The interest of this method is the “control” of a fixed configuration at a given time; the inconvenience is its non-compressible duration.

 

Continuous stirring mode or​ "tuning"

The stirring turns continuously at a defined speed (in function of the equipment reaction time). This mode permits a gain of time but generates important field variations that can disturb some sensitive equipment.