RTu1B: High-Performance RF Oscillators

Presentation Abstract
This session consists of five papers on advanced techniques for high-performance oscillators operating at RF frequencies. The first paper introduces an inverse-class-F VCO utilizing a distributed dual-mode resonator (DMR) instead of a transformer-based tank, enhancing high-Q performance at both fundamental and second harmonic frequencies while suppressing noise conversion and minimizing detrimental third harmonic components. The second paper introduces a quad-core quad-mode VCO utilizing a pure magnetic-coupling technique and a fully symmetrical topology, featuring a centrosymmetric transformer with four coupled inductors and an embedded switched inductor to enable quad-mode operation without frequency tuning range degradation. The third paper presents a series resonance oscillator with bidirectional inductive-mode pulling, enabling ultra-low phase noise and wide tuning range by optimizing mode-switching connections, introducing a balanced-slope NMOS inverter for ripple minimization, and ensuring reliable frequency expansion without added parasitic effects. The fourth paper introduces a coupling-canceling common-mode resonance expansion technique using a tail 8-shaped inductor and staggered tap inductors to enhance wideband common-mode impedance, effectively reducing flicker phase noise without requiring manual tuning. The last paper introduces a multi-tap transformer-based quad-core dual-mode VCO that leverages enhanced electromagnetic mixed-coupling and harmonic-free-like techniques to achieve wideband flicker noise suppression while employing orthogonally stacked dual-core transformers and mode switches to enable a wide frequency tuning range.