论文标题
频谱纯微波信号的产生
Generation of Spectrally Pure Microwave Signals
论文作者
论文摘要
基于微波电路干涉仪的原理，我们构建了一个降低的噪声放大器（RNA），具有相相的功率频谱密度以及幅度，在1 kHz偏移下接近-170 dbc/hz的波动。 RNA已与低温蓝宝石谐振器合并为环振荡器，其噪声性能受Leeson模型的控制。遵循此模型，并使用RNA增益和相波的原位测量结果，我们推断振荡器的噪声特性。特别是，对于通过谐振器传输的信号，我们发现其相/振幅波动的功率光谱密度必须接近300 Hz以上的偏移量接近-185 dBC/Hz。我们讨论了一些方法，可以直接测量如此低水平的噪声。
Based on the principles of microwave circuit interferometry we have constructed a Reduced Noise Amplifier (RNA) with power spectral density of phase, as well as amplitude, fluctuations close to -170 dBc/Hz at 1 kHz offset. The RNA has been incorporated with a cryogenic sapphire resonator as a loop oscillator whose noise performance is governed by the Leeson's model. Following this model and using the results of in-situ measurements of gain and phase fluctuations of the RNA we inferred noise properties of the oscillator. In particular, for a signal transmitted through the resonator we found that power spectral density of its phase/amplitude fluctuations must be close to -185 dBc/Hz at offsets above 300 Hz. We discuss a few approaches that will allow direct measurements of such low levels of noise.
