A fully anechoic chamber has all surfaces covered with anechoic pyramidal material, walkway absorbers allow access.
The object of a fully anechoic chamber is to mimic free space.
The quietness or anechoic performance is known as the ‘Quiet Zone’ or QZ, the QZ is volumetric and can be a cylinder or a sphere.
The performance is relative to the frequency because pyramidal absorber works better where the wave is shorter at the higher frequencies. At lower frequencies (below 1GHz) the absorbers have to be long to address the longer wavelengths.
If a Quiet zone is designed to be, say, -50dB then the absorbers need to be at least 3x the wavelength, to calculate the wavelength: 300/frequency (MHz) = wavelength (mm)
It follows that larger absorber require a larger chamber.
Not all fully anechoic chambers are shielded.
Global EMC Product
Global EMC have done many free space microwave chambers, all have met performance targets.
Global EMC use only the highest performing anechoic absorbers, our GDS system achieves 50dB of return loss at c2.5x wave in normal incidence.
VSWR independent calibration to National standards is available.
Radar cross section
Microwave communication testing (WLAN/mobile phones etc)
About Global EMC
Global EMC UK Ltd has 30 years experience in RFI / EMI / EMC and are specialists in shielding / RF / Microwave absorber applications. Continual development of shielded
rooms (Faraday cages) and anechoic chambers has bought us to the forefront of shielded chamber and anechoic test chamber technology. Read More >