Integrated finline: The second decade. I

Finline technology has been established as a practical approach in the design and construction of mm-wave components and subsystems. The advantages of finline include wide single-mode bandwidth, low insertion loss, freedom from radiation losses, photolithographic production economy, low equivalent dielectric constant, and compatibility with hybrid devices, other IC lines and waveguide instrumentation. In the present paper, a review is provided of the progress in integrated finline and the structure and properties of finline. In an integrated finline structure, longitudinal metal strips and dielectric layers are suspended in the E-plane of a rectangular waveguide housing to provide capacitive loading to the quasi-TE/10/ mode. Attention is given to construction techniques, electrical characteristics, passive elements and discontinuities, finline filters, directional couplers, and attenuators and switches.