What Is a Reverberation Chamber?
A reverberation chamber is a specialized testing device comprising an electromagnetic shielding room (shield room) and an electromagnetic stirring device (Stala). It’s designed to create multiple reflections of electromagnetic waves within its metal walls and varies these reflections through the rotation of the Stala’s blades. This chamber effectively simulates an electromagnetic environment akin to urban areas, making it ideal for electromagnetic compatibility (EMC) testing of modern systems like 4G, 5G, autonomous driving, and connected technologies.
Uses of Reverberation Chamber
Reverberation chambers are primarily used for EMC testing. This includes radiated emission tests, which assess the interference waves emitted by electronic devices and systems, and radiated immunity tests, which evaluate a device’s resistance to external electromagnetic interference. They are essential for ensuring the reliability of vehicle network systems and communication technologies.
Principles and Advantages of Reverberation Chambers
The shield room in a reverberation chamber generates multiple modes or resonance phenomena, significantly influencing the electric field distribution. This setup, akin to acoustic properties in a music room, shows that the materials of the shield room walls are crucial for the internal electric field. The Stala’s role is to create a statistically uniform electromagnetic field, beneficial for radiated immunity tests, as it uniformly irradiates the device under test (DUT) with an electric field, regardless of its position or orientation. In radiated emission tests, especially at higher frequencies, the chamber’s resonance phenomena and the Stala’s rotation efficiently capture maximum radiated noise, reducing measurement time significantly compared to traditional methods.
Other Information on Reverberation Chambers
1. Stirring Methods in Reverberation Chambers
Stirring methods in reverberation chambers include rotating blades, moving wall surfaces, and vibrating flexible mesh-like tent structures on the walls. These methods are vital for generating a uniform electromagnetic field.
2. Metal Walls in Reverberation Chambers
The walls of the shield room in a reverberation chamber are typically made from materials with high conductivity, like copper (Cu) and aluminum (Al). In some cases, steel plates coated with zinc or aluminum are used, particularly effective in the MHz range due to their permeability.
3. On Electromagnetic Fields
The electromagnetic field’s statistical uniformity improves with more rotation steps of the Stala and increased measurement points within the working volume. Understanding this concept is crucial for maximizing the reverberation chamber’s benefits, which differs from deterministic concepts of uniform electromagnetic fields found in open sites or anechoic chambers.