Origin of 1/f PM and AM noise in bipolar junction transistor amplifiers

Walls, F.L.; Ferre-Pikal, E.S.; Jefferts, S.R.

doi:10.1109/58.585117

Cited by 70 publications

(26 citation statements)

References 9 publications

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“…The inherent near-DC noise of an amplifier, which is usually flicker noise, is up-converted and projected partially as phase modulated (PM) noise and partially as amplitude modulated (AM) noise onto the signal being amplified [1][2]. This behavior significantly limits the performance of an amplifier used to amplify and/or distribute low-noise, spectrally pure oscillating signals.…”

Section: Introductionmentioning

confidence: 99%

Low Phase Noise Amplifier and Oscillator Using Feed-Forward Technique at 10 GHz

Hati¹,

Nelson²,

Howe³

2006

2006 IEEE International Frequency Control Symposium and Exposition

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We discuss the performance of a feed-forward amplifier (FFA) at 10 GHz. The feed-forward method is primarily used to suppress intermodulation distortion in amplifiers to suppress up-converted near-DC noise. The main amplifier in this configuration is a low-noise array of eight amplifiers in parallel and having a phase noise of -165 dBc/Hz at f = 10 kHz. By implementing a feedforward scheme, we are able to suppress this noise, as well as close-to-carrier noise, by at least another 10 dB. This improved performance surpasses that of other present low-noise microwave amplifiers. We discuss this exceptional performance in the context of trade-offs with other amplifier properties and specifications.We also construct a 10 GHz oscillator using an air-dielectric resonator and the FFA as the loop amplifier. The phase modulated (PM) noise of this particular oscillator is either less than or comparable to the PM noise of several classes of commercial oscillators. Additionally, the AM noise performance is superior to existing oscillators.

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Section: Introductionmentioning

confidence: 99%

Low Phase Noise Amplifier and Oscillator Using Feed-Forward Technique at 10 GHz

Hati¹,

Nelson²,

Howe³

2006

2006 IEEE International Frequency Control Symposium and Exposition

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“…Shot and thermal noises are responsible for the amplitude modulation (AM) and the phase modulation (PM) of the coherent signal, called a carrier, resulting in equally divided AM and PM noise [1] independent of frequency. This leads to the noise floor of every typical phase-noise spectrum.…”

Section: Introductionmentioning

confidence: 99%

“…The origins of noise in each element of an oscillator taken independently are not clearly identified, but the mechanisms of their transformation into the oscillator loop are quite well-known. Studies have been carried out on the origins of noise in bipolar junction transistor (BJT) amplifiers [1]- [3] and their interactions onto the coherent signal that is processed in the amplifier.…”

Section: Introductionmentioning

confidence: 99%

New phase-noise model for crystal oscillators: application to the Clapp oscillator

Galliou

Sthal

Mourey

2003

IEEE Trans. Ultrason., Ferroelect., Freq. Contr.

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Leeson's is the basic model for predicting oscillator noise. A mathematical analysis of this "heuristic" model has been proposed. Both models do not detail the relative importance of the amplifier transfer function associated to its own noise with regard to that of the resonator. In this paper, an improved version of those previous models is presented. The phase noise generated by the amplifier and the one generated by the resonator are differentiated without considering their origins, such as the conversion of amplitude modulation noise into phase modulation noise. The power spectral densities of phase noise at various points of the oscillator loop are calculated from their respective correlation functions. As a consequence, the influence of the inner amplifier and resonator noises on the resulting oscillator noise is predictable. The model is especially attractive to the makers of widely used quartz oscillators. The resulting oscillator noise is easily obtained from the oscillator open-loop noise. An example of the phase-noise modeling of the Clapp quartz crystal oscillator is simulated and discussed.

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“…The most difficult range of offset frequencies to measure is between 5 and 100 Hz, where the oscillator noise has a slope of f 23 , while the measurement system noise floor follows f 21 . The 2N2222A bipolar junction transistor (BJT) has been successfully used in low-flicker PM noise circuits [1,2] and is chosen as the low noise nonlinear element in a custom-built DBM design. A pair of mixers using this design can be used to construct a cross-correlation PM measurement system to reduce the PM residual noise floor further.…”

mentioning

confidence: 99%

5 MHz phase detector with low residual flicker

et al. 2011

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The measurement of close-to-carrier phase modulation (PM) noise of state-of-the-art oscillators is always challenging. Quite often the residual noise of the phase detector used in these measurements is higher than the noise of the source at Fourier offset frequencies between 5 and 100 Hz. A conventional double balanced mixer using 2N2222A transistors as the nonlinear components of a diode ring was constructed for use as a phase detector. Residual single-sideband PM noise measurements at 5 MHz for this device have shown a low flicker noise floor of L(10 Hz) ¼ 2163 dBc/Hz. When this mixer design is implemented in a dual-channel measurement system, a cross-correlated PM noise floor of better than L(10 Hz) ¼ 2170 dBc/Hz is expected.Introduction: The double balanced mixer (DBM) is the most widely used phase detector for high-resolution phase modulation (PM) noise detection at most carrier frequencies. Often, the measurement of PM noise is difficult owing to the high dynamic range that exists between the carrier and the modulated sidebands. In typical measurement systems, a phase detector is used to remove the carrier and downconvert noise sidebands to baseband. For offset frequencies close to the carrier, the residual flicker noise of the DBM is often the limiting factor of a phase noise measurement system. The most difficult range of offset frequencies to measure is between 5 and 100 Hz, where the oscillator noise has a slope of f 23 , while the measurement system noise floor follows f 21 . The 2N2222A bipolar junction transistor (BJT) has been successfully used in low-flicker PM noise circuits [1,2] and is chosen as the low noise nonlinear element in a custom-built DBM design. A pair of mixers using this design can be used to construct a cross-correlation PM measurement system to reduce the PM residual noise floor further.

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Origin of 1/f PM and AM noise in bipolar junction transistor amplifiers

Cited by 70 publications

References 9 publications

Low Phase Noise Amplifier and Oscillator Using Feed-Forward Technique at 10 GHz

Low Phase Noise Amplifier and Oscillator Using Feed-Forward Technique at 10 GHz

New phase-noise model for crystal oscillators: application to the Clapp oscillator

5 MHz phase detector with low residual flicker

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