the anechoic chamber is mainly composed of shielding chamber and microwave absorbing material. the shielding room is composed of shielding shell, shielding door, ventilation waveguide window and various power filters. according to user requirements, the shielding shell can be welded or assembled. the absorbing material is composed of a single-layer ferrite sheet with a working frequency range of 30mhz ~ 1000mhz and a conical carbon sponge absorbing material. the conical carbon sponge absorbing material is made of polyurethane foam infiltrated in carbon glue solution and has good flame retardant characteristics.