Feature 100 Years of Colpitts Oscillators: Ontology Review of Common Oscillator Circuit Topologies LING ©SHU K/P STOC TTER Abstract Mehdi Azadmehr, Igor Paprotny, and Luca Marchetti Digital Object Identifier 10.1109/MCAS.2020.3027334 Date of current version: 12 November 2020 8â IEEE CIRCUITS AND SYSTEMS MAGAZINE The year 2018 marked 100 years since the introduction of a class of oscillatory circuits called Colpitts oscillators. Few other electronic circuits have survived for such a long time and affected the electronic technology as the Colpitts oscillator. Today, Colpitts oscillators are found in both communication systems and digital circuits as clock and frequency generators. In this paper, we provide a comprehensive overview over the development of the Colpitts oscillator, from the simple vacuum tube oscillator patented by Colpitts in 1918, to state of the art MEMS oscillators operating at high GHz region in today's modern electronics. 1531-636X/20©2020IEEE FOURTH QUARTER 2020