Ultra-Low Phase Noise Ceramic based Dielectric Resonator Oscillators

This paper describes, in general terms, the theory and design of ultra-low noise oscillators based on ceramic dielectric resonators and in particular oscillators operating at L and C band. This extends as presented in M. Sallin et al. (2003) at L band the new oscillators offer <-170dBc/Hz at 10kHz offsets with noise floors below -180dBc/Hz beyond 50kHz offset. Results at other frequencies up to 10GHz are also presented. The AM noise has been measured to be significantly below the PM noise at most offsets. To achieve this performance the amplifiers resonators and tuning elements have been extensively optimised. For example L band amplifiers produce very low residual flicker noise <-180dBc at 10kHz offset