Up-converted 1/f PM and AM noise in linear HBT amplifiers

In this paper we describe a technique to predict the 1/f phase modulation (PM) and 1/f amplitude modulation (AM) noise due to up-conversion of 1/f baseband current noise in microwave heterojunction bipolar transistor (HBT) amplifiers. We obtain an accurate model for the amplifier and find the expression for voltage gain in terms of DC bias, transistor parameters, and circuit components. Theoretical 1/f PM and AM noise sensitivities to 1/f baseband current noise are then found by applying the definitions of PM and AM noise to the gain expression of the amplifier. Measurements of PM and AM sensitivities at 500 MHz and 1 GHz were in good agreement with the values predicted by theory, verifying the validity of this technique. This method can be used to optimize amplifier design for low PM and AM noise. We show that the amplifier PM noise can be reduced by 9 dB by adjusting the value of the input coupling capacitor.     

Guidelines for designing BJT amplifiers with low 1/f AM and PM noise

In this paper we discuss guidelines for designing linear bipolar junction transistor amplifiers with low 1/f amplitude modulation (AM) and phase modulation (PM) noise. These guidelines are derived from a new theory that relates AM and PM noise to transconductance fluctuations, junction capacitance fluctuations, and circuit architecture. We analyze the noise equations of each process for a common emitter (CE) amplifier and use the results to suggest amplifier designs that minimize the 1/f noise while providing other required attributes such as high gain. Although we use a CE amplifier as an example, the procedure applies to other configurations as well. Experimental noise results for several amplifier configurations are presented.     

Vibration-induced PM and AM noise in microwave components

The performance of microwave components is sensitive to vibrations to some extent. Aside from the resonator, microwave cables, and connectors, bandpass filters, mechanical phase shifters, and some nonlinear components are the most sensitive. The local oscillator is one of the prime performance-limiting components in microwave systems ranging from simple RF receivers to advanced radars. The increasing present and future demand for low acceleration sensitive oscillators, approaching 10?13/g, requires a reexamination of sensitivities of basic nonoscillatory building-block components under vibration. The purpose of this paper is to study the phase-modulation (PM) noise performance of an assortment of oscillatory and nonoscillatory microwave components under vibration at 10 GHz. We point out some challenges and provide suggestions for the accurate measurement of vibration sensitivity of these components. We also study the effect of vibration on the amplitude-modulation (AM) noise.     

Flicker (1/f) noise in tunnel junction dc SQUIDS

We have measured the spectral density of the 1/f voltage noise in current-biased resistively shunted Josephson tunnel junctions and dc SQUIDs. A theory in which fluctuations in the temperature give rise to fluctuations in the critical current and hence in the voltage predicts the magnitude of the noise quite accurately for junctions with areas of about 2 × 10⁴ µm², but significantly overestimates the noise for junctions with areas of about 6 µm². DC SQUIDs fabricated from these two types of junctions exhibit substantially more 1/f voltage noise than would be predicted from a model in which the noise arises from critical current fluctuations in the junctions. This result was confirmed by an experiment involving two different bias current and flux modulation schemes, which demonstrated that the predominant 1/f voltage noise arises not from critical current fluctuations, but from some unknown source that can be regarded as an apparent 1/f flux noise. Measurements on five different configurations of dc SQUIDs fabricated with thin-film tunnel junctions and with widely varying areas, inductances, and junction capacitances show that the spectral density of the 1/f equivalent flux noise is roughly constant, within a factor of three of (10^?10/f)? ₀ ² Hz^?1. It is emphasized that 1/f flux noise may not be the predominant source of 1/f noise in SQUIDS fabricated with other technologies.     

Relationship of AM to PM noise in selected RF oscillators

We have studied the amplitude modulation (AM) and phase modulation (PM) noise in a number of 5 MHz and 100 MHz oscillators to provide a basis for developing models of the origin of AM noise. To adequately characterize the AM noise in high performance quartz oscillators, we found it necessary to use two-channel cross-correlation AM detection. In the quartz oscillators studied, the power spectral density (PSD) of the f(-1) and f(0) regions of AM noise is closely related to that of the PM noise. The major difference between different oscillators of the same design depends on the flicker noise performance of the resonator. We therefore propose that the f(-1) and f(0) regions of AM and PM noise arise from the same physical processes, probably originating in the sustaining amplifier.     

双极型光栅晶体管的瞬态特性模型及模拟分析

提出一种应用于CMOS图像传感器的新型光电检测器件-双极型光栅晶体管，并建立了其瞬态等效电路模型，利用电路模拟软件HSPICE的多瞬态分析法对双极型光栅晶体管的光电流特性进行了仿真，分析得出这种新型器件在0.6μmCMOS工艺参数下，由于引入pn注入结加速了光电荷的读出速率，光电流随外加电压呈指数式增长，与普通光栅晶体管相比，蓝光响应特性有较大改善。     

Quality and 1/f noise of electronic components

Classification rules of electronic components based on their 1/f noise measurements are presented. It is proposed to classify electronic components into four groups with different quality: high, good, low, poor. The results of investigations of type BF 414 transistors are reported.     

Optical control of low frequency noise behavior in cryogenic GaAs junction field effect transistor

We demonstrated optical control of low frequency noise in n-type GaAs junction field effect transistors (JFETs) at cryogenic temperature. At 4.2 K, a 6 dB decrease and a 10 dB increase in noise at 1 Hz were observed when the JFET (band gap: 1.51 eV) was illuminated by light with wavelengths of 1650 and 1550 nm, respectively, for a drain voltage of 0.5 V and drain current of 0.25 μA. On the other hand, the wavelength with the noise reduction effect decreased to 1550 nm at 30 K. These results mean the trap charges at an energy level of approximately 0.75 ± 0.1 eV affect the carrier tunnel probability and the behavior of the low frequency noise.     

Correlation between 1/f noise and semiconductor laser degradation

The origin of the increase in residual spectral linewidth during device degradation is experimentally and theoretically clarified in a multiple quantum well (MQW) distributed feedback (DFB) laser. Non-radiative recombination current increases during device degradation and causes 1/f noise to increase. This current 1/f noise is the origin of the increase in the residual spectral linewidth. Through these degradation behaviours, a model showing a correlation between 1/f noise and the semiconductor laser degradation is proposed.     

Measurement of 1/f noise and its application in materials science

This is a review of the measurement of 1/f noise in certain classes of materials which have a wide range of potential applications. This includes metal films, semiconductors, metallic oxides and inhomogeneous systems such as composites. The review contains a basic introduction to this field, the theories and models and follows it up with a discussion on measurement methods. There are discussions on specific examples of the application of noise spectroscopy in the field of materials science.     

Secondary standard for PM and AM noise at 5, 10, and 100 MHz

A practical implementation of a portable secondary standard for phase modulation (PM) and amplitude modulation (AM) noise at 5, 10, and 100 MHz is described. The accuracy of the standard for both PM and AM noise is +0.14 dB, and the temperature coefficient is less than 0.02 dB/K. The noise floor S_φ (10 kHz) of the standard for PM noise measurements is less than -190 dBC relative to 1 rad²/Hz at 5, 10, and 100 MHz. The noise floor for AM measurements depends on the configuration. A calibrated level of PM and AM noise of approximately -130±0.2 dB relative to 1 rad² /Hz (for Fourier frequencies from approximately 1 Hz to 10% of the carrier frequency) is used to evaluate the accuracy versus Fourier frequency. Similar PM/AM noise standards are under test at 10 GHz. This new standard can also be used as an alternative to the normal method of calibrating the conversion sensitivity of the PM/AM detector for PM/AM measurements. Some types of time-domain measurement equipment can also be calibrated     

1/f noise in a model of intersecting phase transitions

A mathematical model for the appearance of fluctuations with a spectrum inversely proportional to the frequency (flicker or 1/f noise) upon the intersection of phase transitions is proposed. A system with a two-valley potential, whose dynamics are described by two coupled nonlinear Langevin equations that transform Gaussian δ-correlated noise (white noise) into two modes of stochastic fluctuations with spectra having 1/f ^μ and 1/f ^v frequency distributions, where μ ≈ 1 and 1.5 ? v ? 2, is considered.     

再论1/f噪声的动力学统计理论

在《1/f噪声的动力学统计理论》一文中,为了突出重点,攻克主要矛盾,因而对1/f噪声的某些特点,如实验上发现的1/f噪声的功率谱S(f)为什么总是1/fM能谱和功率谱S(f)为何是同一函数等等,当时未能深入追究,本文除了弥补这些不足之外,还从“零点能”与“暗物质”而引发的“背景能量的涌动”这个深层次上来解释普适关系式:S(f)∝logf/f。     

Measurement of AM to PM conversion in medium wave AM transmitter

A method for measuring AM (amplitude modulation) signal distortion caused by AM to PM (phase modulation) conversion at the output of an AM radio transmitter is presented. A novel type of measuring instrument is also presented for testing the phase distortion which may occur in an AM radio transmitter when an AM modulation signal is applied. The down-converted AM signal is first divided into the inphase and orthogonal-phase components, and these signals are processed by an operational circuit to obtain phase distortion, which is the angle between the orthogonal-phase and inphase components. A phase angle of 10° or more is detected in the prototype version     

On the 1/f frequency noise in ultra-stable quartz oscillators

The frequency flicker of an oscillator, which appears as a 1/f3 line in the phase noise spectral density, and as a floor on the Allan deviation plot, originates from two basic phenomena, namely, (1) the 1/f phase noise turned into 1/f frequency noise via the Leeson effect, and (2) the 1/f fluctuation of the resonator natural frequency. The discussion on which is the dominant effect, thus on how to improve the stability of the oscillator, has been going on for years without giving a clear answer. This article tackles the question by analyzing the phase noise spectrum of several commercial oscillators and laboratory prototypes, and demonstrates that the fluctuation of the resonator natural frequency is the dominant effect. The investigation method starts from reverse engineering the oscillator phase noise in order to show that if the Leeson effect was dominant, the resonator merit factor Q would be too low as compared to the available technology.     

2.27 1/f noise voltage in a thin film structure

1/f noise in current carrying thin film devices is caused by fluctuation of the electrical conductivity of the film material. Describing its effect on the voltage distribution in a device requires a two-dimensional analysis. This may be done by means of a theory, presented in this article, where the fluctuation is treated as current dipoles.The geometrical dependence of the noise intensity across electrodes on Hall generator structures, made from InSb thin films, is measured. This is in fair agreement with predictions based on the theory.     

Amplifier using p-n junction field-effect transistors with 1/f-type noise

Conclusions The KPS104A field-effect transistor, which produces practically no 1/f-type noise down to frequencies f2 Hz, may be used to advantage as the active element of a high-sensitivity amplifier at subsonic frequencies.Translated from Izmeritel'naya Tekhnika, No. 3, pp. 38–39, March, 1979.     

Structure and 1/f noise of boron doped polymorphous silicon films

The influence of structure variation on the 1/f noise of nanometric boron doped hydrogenated polymorphous silicon (pm-Si:H) films was investigated. The films were grown by the conventional radio frequency plasma enhanced chemical vapor deposition (PECVD) method. Raman spectroscopy was used to reveal the crystalline volume fraction (X(c)) and crystal size of the pm-Si:H. The measurement of optical and structure properties was carried out with spectroscopic ellipsometry (SE) in the Tauc-Lorentz model. A Fourier transform infrared (FTIR) spectrometer was used to characterize the presence of nanostructure-sized silicon clusters in pm-Si:H film deposited on KBr substrate. The electrical properties of the films were measured using evaporated coplanar nickel as the electrode. A semiconductor system was designed to obtain the 1/f noise of pm-Si:H film as well as that of amorphous and microcrystalline silicon films. The results demonstrate that the 1/f noise of pm-Si:H is nearly as low as that of microcrystalline silicon and much lower than that of amorphous silicon. The disorder to order transition mechanism of crystallization was used to analyze the decrease of noise compared with amorphous silicon.     

1/f noise of electrolytic capacitors as a reliability indicator

The electrical noise of capacitors and the relationship between typical imperfections in capacitors and their excess noise are described. It was assumed that a noisy capacitor is a poor-quality one. Investigations were aimed at the determination of a correlation between the inherent noise of capacitors and their reliability (time to failure) and also at the determination of an indicator to predict reliability. Investigations (noise measurements and reliability tests) were carried out on two samples of aluminium electrolytic capacitors. The method of reliability prediction for electrolytic capacitors based on their low-frequency noise is described. For reliability prediction the noise intensity G at a frequency of 2 Hz was used as a reliability indicator. It was found that the evaluated correlation coefficients between the noise parameter G and the time to failure, t, are statistically significant. It is concluded that it is possible to predict the lifetime of aluminium electrolytic capacitors on the basis of their 1/f noise. © 1998 John Wiley & Sons, Ltd.     

Dependence of SAW resonator 1/f noise on device size

Experiments were conducted with eight 450-MHz surface acoustic wave (SAW) resonators which demonstrate that a resonator's 1/f noise depends approximately inversely on the active acoustic area of the device. This observation is consistent with a proposed theory that 1/f noise in acoustic resonators is caused by localized velocity or dimensional fluctuations.