Novel microceramic structures for the design of monolithic millimeter-wave passive front-end components

Development and production of millimeter-wave (MMW) technology has been hindered by the lack of suitable technology and techniques that would enable automated fabrication of monolithic subsystems with proper low-loss materials. Ceramics provide significant advantages over other materials at MMW frequencies due to their very high Q. Direct ceramic stereolithography (Cer-SLA) (Griffith, M.L. and Halloran, J.W., J. American Ceramic Society, vol.79, 1996) offers an accurate rapid prototyping method for three-dimensional macroscopic designs of arbitrary complexity. The paper proposes a technique to obtain a wide range of effective dielectrics by employing the Cer-SLA process to construct sub-millimeter scale regular periodic substructures of variable ceramic-to-air volume ratios. Low-frequency approximations are compared to simulated effective dielectric constants at millimeter-wave frequencies. The results may provide a basis for future design of arbitrarily complex dielectric profiles.