Study of the Influence of Several Nonmetal Sheets to 100GHz Millimeter Wave Active Imaging

摘要

A 100GHz millimeter high speed linear camera and a 100GHz radiation source has been combined with a transmission band which running at a uniform speed to form a set of initiative terahertz imaging system. According to the characteristic of initiative terahertz imaging system, an iron circle was used to be as a target, and the imaging effect has been tested when the target was covered by some silk, black insulation rubber, white silicon rubber, paperboard, expandable polyethylene, polystyrene cystosepiment, leather cloth or carbon fiber cloth. The change law of the brightness has been studied and an equation has been built to indicate the brightness of the target varies with the thickness of the covered sheets. As a result, 100GHz millimeter wave can penetrate many objects to detect metal target except carbon fiber cloth, rubbers and other special objects. When the imaging system is used to be a set of security check, the power of the radiation source must be enough great to catch the weak signal coming from the metal target covered by opaque materials to millimeter wave. When an unknown or black object appears in watching screen, the security check must be done by hand to confirm whether there is a piece of metal or other special object.