Reverberation Chamber Test

What is Reverberation Test Chamber?

The reverberation room, sometimes known as a mode-set or mode-shuffle chamber, is surrounded by a shielded enclosure and resonant for RF testing, and this compartment is statistically isotropic, also randomly polarized and has RF homogeneity within the specified limits. Typically, a reverberation chamber has a receiver that mixes the area and randomly separates boundary conditions.

There are two types of Echo Test methods. “Regulated mode” means that the paddle wheel has been brought into position and that RF has been applied for a sufficient waiting time to operate the equipment. This tuner can be driven by a computer-controlled stepper motor that also operates RF generation and monitoring equipment.

The second type, "Shuffle mode", is the time when the racket is constantly cycled by RF energy for a complete motion. The paddle speed has been changed to meet the specific requirements of the device under test.

In both methods, the single and full rotation of the racket applies RF energy to each side of the device in one pass. This greatly simplifies the process compared to the direct lighting test.

What are the benefits of Reverberation Test?

The reverberation test has many benefits. RF is applied to all exposed sides of the device (DUT) tested during full 360 ° rotation of the paddle instead of one side. For direct lighting testing, many standards require that all openings of the DUT are illuminated. With complex items, this can be difficult - even impossible. The window effects test required when applying direct illumination is not necessary during the reverb test as the field density changes constantly. Test repeatability is much easier to achieve in an echo chamber with appropriate operations, and running the test is much less complicated than a single aspect angle test. Antenna distance, aim (focus), 3 dB beam width, location of the field probe, EUT layout, and the location of the EUT in the working volume affect the repeatability of the test less.

When is the Reverberation Room used?

Echo chambers are useful for radiation sensitivity, radiation emissions (total radiation power), shielding effectiveness, and many other troubleshooting scenarios for equipment used in the Aviation, Defense and Automotive industries. The echo test method is called the preferred method in SAE ARP 5583, which says it is the recommended and preferred method to demonstrate suitability for large or complex Level A (flight critical) systems.

FAA, AEROCAE, RTCA and large body manufacturers (Boeing, Airbus, etc.) prefer due to time and cost savings and the robustness of the reverberation test method.

Reverb chambers are polarly random and challenging to determine the directivity of RF energy. Multiple field levels can be difficult to test on a system, such as outside the pressure vessel level and inside the pressure vessel level; All equipment in the chamber is exposed to the same area. There are limitations in pulse width due to a high Q (efficient) chamber with a large amount of stored energy. If you have small, simple equipment, single aspect angle tests can be faster and sufficient for test coverage. There are ways to make up for each.

Both direct illumination and reverberation test methods are acceptable ways for certification. Both have their benefits and disadvantages as the test method. EUROLAB has an expert team for both methods.