Patent Number: 
Section: abstract

A THz system has a housing configured to minimize both external noise and internal stray THz waves. The housing material is selected according to the frequency range of THz waves to be propagated though the space enclosed by the housing. In general, the housing is made of foam material, such as low relative dielectric constant foam material, especially foam with conductive additives. The relative dielectric constant of foam material is usually approach to 1.0, which may minimize the reflection of THz waves propagating into the housing. The conductive additives may increase the absorption of the THz waves, even other electromagnetic waves, inside the housing. Clearly, by using proper material, such as Expanded Polypropylene (EPP) and/or Styrofoam, with proper conductive additives, such as graphite, carbon, sliver, absorptive particles/dyes, the housing may minimize the interference of undesired stray terahertz-gigahertz waves, even other noise.