2results about How to "Improve Phase Noise Performance" patented technology

The invention relates to the field of integrated circuits, in particular to a low-phase-noise differential oscillator, a self-adaptive biasing circuit and application of the low-phase-noise differential oscillator and the self-adaptive biasing circuit. The oscillator adopts a Class-C architecture, and a self-adaptive bias circuit composed of two bias copy transistors, an integrating capacitor and a bias resistor is introduced. The self-adaptive biasing circuit and the Class-C oscillator can form a feedback loop, so that the differential crystal oscillator can reliably start oscillation in a C-type working mode; and the conduction angle of the cross coupling pair is limited in a relatively small range, so that extra noise is prevented from being introduced by an overlarge conduction angle. The adaptive biasing circuit can further reduce the pole frequency corresponding to a low-frequency additional resonance point introduced by the Class-C structure. Therefore, the problem that the differential crystal oscillator is difficult to give consideration to reliable oscillation starting and parasitic oscillation suppression is solved.

This invention relates to the field of integrated circuit technology, specifically to a Class F series resonant voltage-controlled oscillator, which consists of four identical unit circuits connected end to end to form a closed loop structure. Each unit circuit includes an active circuit and an LC series resonant network. The LC series resonant network includes a main resonant cavity and an auxiliary resonant cavity. This invention achieves a systematic improvement in phase noise performance through the series resonant topology and harmonic shaping mechanism.