Recent British Work on Millimetric Waveguide Systems

A comprehensive United Kingdom program of research and development on guided millimetric waves concentrates its main effort on a 50-mm internal diameter lightweight helix waveguide, but a lightweight dielectric-lined waveguide is also being investigated. A full-scale Post Office/industry field trial over a 14.1-kin route is scheduled for 1975. Problems of mechanical construction of waveguides are discussed, as well as communication systems aspects. Attention is paid to terminal/repeater equipment, band-branching assemblies, transmitter-receiver equipment (using 500-Mbit/s quadrature PSK modulation), regenerators, differential demodulators, and IMPATT diode oscillators. High reliability is also required of high-efficiency solidstate oscillators.