推–推振荡器共用谐振器分析与低相位噪声设计

Common resonator analysis and low phase-noise design in push-push oscillator

为实现低相位噪声平面振荡器,对推-推振荡器的共用谐振器与相位噪声优化方法进行了研究。提出一种基于多环式开口谐振环的差分传输线,通过加载一对耦合谐振环的方式实现2个单元振荡器之间的弱耦合,提高了共用谐振器的频率选择特性。基于该结构设计并实现了一种X波段推-推振荡器,在设计中采用一种基于振荡器有源品质因子的相位噪声优化方法。测试结果表明:该振荡器在输出二次谐波9.52GHz处的相位噪声为-115.48 dBc/Hz@100 kHz,基波抑制度达到-54.55 dBc。

In order to obtain low phase noise planar oscillator,the common resonator and phase noise optimization method in push-push oscillators are studied in this paper.Firstly,a differential transmission line loaded by a coupled-pair of multiple split ring resonators is proposed to achieve weak coupling between two sub-oscillators,and the frequency selectivity of common resonator is improved.Then an X-band push-push oscillator utilizing this structure is designed and realized,and a phase noise optimization method based on active quality factor of oscillator is adopted in the design.The measured phase noise is-115.48 dBc/Hz@100 kHz offset at the second harmonic frequency of 9.52 GHz,and the suppression of fundamental frequency component achieves-54.55 dBc.