Oscillator phase-noise reduction using active inductor

In this paper the design of an oscillator based on active inductor (AI) is presented, and the advantages resulting from this approach in term of phase-noise reduction are illustrated. Replacing the inductor with the AI in a classical LC-resonator give significant advantages, due to the high quality factor of the AI and the corresponding high frequency-selectivity of the active resonator. As a proof of concept, three different oscillators at 2.35GHz have been designed, fabricated and tested. A comparison of the performances of a varactor-based resonator, an AI solution and a classical DRO configuration is carried out, showing the advantages of the proposed approach.