Generation of Millimeter-Wave Signals of High Spectral Purity

The generation of millimeter-(mm-) wave signals phase coherent to a lower frequency reference or standard implies a large multiplication factor with inherent amplification of the short term instability or phase noise. This effect which usually is of secondary importance at lower microwave frequencies may become a limiting factor in the implementation of some mm-wave digital communication systems. Techniques used for the generation of signals of high spectral purity are discussed, and illustrated with the realization for a low data rate mm-wave satellite communications system. Quantitative results are presented and analyzed in terms of the theoretical time and frequency domain relationships.