Y-Junction Circulator at 258 Ghz (Correspondence)

The authors have developed a three-port ckculator at 258 GHz as part of an amplifier operating on the principle of resonance saturation of a dipolar gas. The circulator consists of a symmetric Y-junction with au accurately centered ferrite post. The groove dimension corresponds to RG137 rectangular waveguide (0.043 inch by 0.0215 inch). This geometry was found to have at the given frequency the least loss. The design is similar to circulators obtained by others at 140 GHz. Constructional features are a split-machined structure, optical polished and gold plated surfaces, and integrated flanges.