A 1-GHz full cryogenic oscillator is presented. The oscillator is based on a planar superconductor resonator featuring a loaded ${Q}$ factor of 200 000 at low microwave input power (unloaded ${Q}$ of 400 000) and on amplifying parts realized with SiGe bipolar transistors. The circuit is designed with a harmonic balance software and realized on an alumina substrate. A nonlinear model is extracted at low temperature both for the transistor and the resonator. This double nonlinearity increases the difficulty of the oscillator design and implies a strategy to limit the power inside the resonator. The vibrations of the cryogenerator are also a serious issue to get high performance. Finally, the oscillator features a phase noise of −112 dBc/Hz at 100-Hz offset frequency and a phase noise floor of −170 dBc/Hz (100-kHz offset) at a temperature of 65 K.

中文翻译：

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基于超导体谐振器的低相位噪声全低温微波振荡器

提出了一种1 GHz全低温振荡器。该振荡器基于一个平面超导体谐振器，该谐振器具有负载 $ {Q} $ 在低微波输入功率下（空载）为20万 $ {Q} $ （400,000个）和使用SiGe双极晶体管实现的放大部件。该电路采用谐波平衡软件进行设计，并在氧化铝基板上实现。在低温下为晶体管和谐振器提取非线性模型。这种双重非线性增加了振荡器设计的难度，并暗示了一种限制谐振器内部功率的策略。低温发生器的振动也是获得高性能的重要问题。最后，该振荡器在100Hz偏移频率下具有-112 dBc / Hz的相位噪声，在65 K温度下具有-170 dBc / Hz（100kHz偏移）的本底噪声。