ABSTRACT
Low-loss materials are needed for MMW and subMMW guiding systems (dielectric and microstrip waveguides, quasi-optical lens waveguides) and their components (phase shifters, directional couplers and power dividers, prisms, polarizers etc.), for antenna systems (lenses, antenna covers, frequency selec tive screens), as well as for transmission windows for vacuum tube generators (e.g. gyrotrons) [1-6]. Information concerning material complex refractive indices n* = n - ik is also of a great interest for MMW and subMMW introscopy, material and media testing (first of all for aquametry), for propagation prob lems including indoor propagation, for some industrial and medical applications [1,3,7~9].
