125 GHz Frequency Doubler using a Waveguide Cavity Produced by Micro Stereolithography

This technical paper reports on the first Schottky diode frequency doubler with a split-block waveguide structure fabricated by a high-precision projection micro-stereolithography (PµSL) printing process. The printed polymer waveguide parts were plated with copper and a thin protective layer of gold. The surface roughness of the printed waveguide parts has been characterized and the critical dimensions measured, revealing good printing quality as well as a dimensional accuracy that meets the tight tolerance requirements for sub-terahertz active devices.