High resolution reflection measurements of dielectrics in W-band (92–100 GHz)

High resolution high power W-band (92-100 GHz) spectroscopic system was design, constructed and experimentally tested. The system is based upon two parabolic mirrors and two diagonal mirrors, high power high resolution continuous wave tunable THz source and unique THz detector. The spectrometer is fully computerized. The quasi-optical system was design to transfer maximum beam power with minimum aberrations and minimum system internal reflections. Stray refractions were eliminated by placing absorber blocks around the system. Spectral resolution in the order of tens of kHz is achievable. The system was designed to measure transmission function, reflection function, back scattering and forward scattering of samples using wide collimated beam of 75 mm diameter in order to simulate THz imaging situation. A special particle cell was constructed in order to investigate the transmission function and reflection function of turbulent particles in the atmosphere. Reflection measurements with different incidence angles of various materials are given in this study. The experimental results prove that w-band imaging of dielectric materials is feasible. Furthermore, the illumination of the objects can be done with different angles on incident beam.