Low phase noise oscillator topologies: Theory and application to MMIC VCOs

In the paper the advantages of the push-push oscillator topology in terms of phase noise performance are discussed and experimentally verified by means of measurements on X-band and C-band GaInP-GaAs MMIC VCOs. In particular an analytical approach, based on the frequency sensitivity pushing factor parameter, is used to demonstrate the phase noise improvement of at least 9 dB inherently offered by push-push topology, with respect to a fundamental frequency oscillator. This theoretical analysis is for the first time experimentally validated trough the design and characterization of three different MMIC VCOs, specifically developed for this purpose.