CMOS LC voltage-controlled oscillators: a survey

LC oscillators are among the key building blocks in modern electronic systems, and their design and performance are continuously advancing. This report provides a comprehensive review of research and development trends in CMOS LC oscillator design over the past two decades. We first review the principles governing LC oscillator operation and go over their key performance metrics such as phase noise and frequency tuning range. Then various classes of voltage-controlled oscillators (VCOs) are overviewed, highlighting their distinct characteristics and applications. Furthermore, advanced oscillator topologies designed to improve tuning range, power efficiency, and phase noise are explored. To extend the discussion on oscillator architectures, the concept of injection locking and the implementation of injection-locked oscillators (ILOs) are analyzed. Additionally, common design challenges and trade-offs associated with the presented topologies are discussed. The review concludes with an examination of recent advancements in oscillators operating in the terahertz (THz) frequency range, emphasizing the critical role of LC oscillators in such applications.