Anechoic chamber

Anechoic chamber is the place for radiation emission test and radiation immunity test. According to the test distance, it is divided into 3M method darkroom and 10m method darkroom. Ten meters and three meters refer to the distance between the object to be tested (hereinafter referred to as EUT) and the antenna. The ten meter anechoic chamber is generally a ten meter and a half anechoic chamber, which means that the other five sides except the ground are closed spaces paved with microwave absorbing materials, and the ground is metal ground, which can simulate an open space without reflection. The 10m method semi anechoic chamber can be used for radiation emission test, radiation immunity test, shielding efficiency test and other EMC tests. Combined with radiation disturbance and radiation immunity test system, the following requirements are met:

01

There are five main technical indexes of 10m method anechoic chamber: shielding efficiency, normalized site attenuation, site voltage standing wave ratio, field uniformity and environmental noise. 10m method anechoic chamber mainly includes: anechoic chamber body, shielding control room, shielding load room, shielding power amplifier room, hub working room, etc. The main facilities of 10m method anechoic chamber include: shielding body and steel structure, shielding door, absorbing material, turntable and hub, antenna tower, filter, etc.

02

3M method anechoic chamber is generally a semi / full conversion anechoic chamber. The so-called full anechoic chamber refers to the anechoic chamber with six surfaces laid with microwave absorbing materials, which can carry out radiation immunity test; The so-called semi anechoic chamber refers to the anechoic chamber in which the ground is metal and the other five surfaces are absorbing materials. The three meter method anechoic chamber can convert the semi / full anechoic chamber. Facilitate testing requirements.

03

Shielding room refers to a hexahedral metal room with splicing structure or welding structure. Taking the shielding room of electromagnetic compatibility laboratory of Chinese Academy of electrical sciences as an example, the shielding efficiency (SE) reaches more than 90dB in 10kHz ~ 150kHz frequency band and more than 110dB in 150kHz ~ 18GHz frequency band. Can meet the standard requirements. 24 electromagnetic compatibility tests of gb17626 series and gb17625 series can be carried out in the shielding room.