Microwave data bus technology

The main characteristics of some advanced microwave technology available for microwave data buses in the 19 to 23-GHz band are given. This includes transmission lines, signal sources, bus couplers, and digital phase modulators and demodulators. A tunable ring-coupled bus coupler is described that features a four-wavelength ring whose loss is varied by a dielectric vane introduced in the center plane of the guide. Ring attenuations result in a broadening of the bandwidth and a reduction of the main-line insertion loss. Possible system performances with the technology described are discussed.