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EMI/RFI Shielded Honeycomb cut-off Ventilation
Honeycomb cut-off Ventilation is the main channels of air exchanging for Microwave anechoic chamber, EMC Anechoic Chamber, Antenna Far-field / Near-field Measurement Anechoic Chamber and etc. It can effectively cut-off the access of electromagnetic waves. Honeycomb cut-off Ventilation is composed of many small waveguide beam, with hexagonal cross-sectional shape.
Selection principles: insertion loss should be matched with shielding effectiveness of anechoic chamber; it should meet ventilation requirements of anechoic chamber. Honeycomb Ventilation adopts our standard size 300×300 (mm), in the frequency of 40GHz, the distance between two parallel waveguide planes is 3.2mm, and waveguide depth is 40mm. This proposal adopts 3.2mm hexagonal waveguide hole. Hexagonal waveguide cut-off frequency: fc = 6.92×25.4/w = 55.0GHz >40GHz, it can meet the requirements of cut-off frequency. ("w" is circumscribed circle diameter of small hexagonal waveguide hole) Hexagonal waveguide Ventilation, when waveguide depth is 40mm, and frequency is 40GHz, shielding effectiveness is as follow: AE=0.182×f×L×[(fc/f)2-1]0.5= 0.182×40×40[(55.0/40)2-1]0.5 =180(dB) It can meet the requirements of shielding effectiveness.
The waveguide film of Honeycomb Ventilation is produced through vacuum brazing welding technology. When waveguide Ventilation welded with shielding body, it should keep good electrical connections, avoiding missing & false welding. According to the size of wind pipe, waveguide ventilation can be combined as the specification of 600mm×300mm (Size can be customized).
EMI/RFI Shielded Honeycomb cut-off Ventilation