1/f Noise

Noise can assist neurons in the detection of weak signals via a mechanism known as stochastic resonance ͑SR͒. In a previous study ͓Phys. Lett. A 243, 281 ͑1998͔͒, we showed that when colored noise with 1/f ␤ spectrum is added to the FitzHugh-Nagumo ͑FHN͒ neuronal model, the optimal noise variance for SR could be minimized with ␤Ϸ1. In this study, we investigate analytically how the noise color (␤) affects the SR profile in a linearized version of the FHN model. We demonstrate that the aforementioned effect of 1/f noise is related to the dynamical characteristics of the model neuron, i.e., the refractory period, the low-pass filtering effect of the membrane capacitance, and the high-pass filtering effect of the recovery variable.

We show that certain extended dissipative dynamical systems naturally evolve into a critical state, with no characteristic time or length scales. The temporal "fingerprint" of the self-organized critical state is the presence of flicker noise or 1/f noise; its spatial signature is the emergence of scaleinvariant (fractal) structure.

We investigate hot-carrier degradation of the 1 -noise behavior of n-and p-MOS transistors under typical bias conditions for analog and RF operation. The mechanisms responsible for the degradation and a model are discussed for both n-and p-MOS devices. A method for lifetime prediction concerning 1 -noise degradation is presented and consequences for reliability assurance by measures of circuit design are drawn. Index Terms-1 -noise, analog, flicker noise, hot carrier, MOS, MOSFET, noise, RF.

Accurate and detailed noise calculations for operational amplifier circuits using MATLAB are proposed. The analysis of the basic op amp circuits (inverting, non-inverting and differential circuits) is performed taking into account the specifics of current and voltage amplifiers. The MATLAB function m-files are developed to predict the noise. The following characteristics are calculated: total output spot noise voltage; total equivalent

A low noise constant current source used for measuring the 1/f noise in disordered systems in ohmic as well as non-ohmic regime is described. The source can supply low noise constant current starting from as low as 1 µA to a few tens of mA with a high voltage compliance limit of around 20 Volts. The constant current source has several stages which can work in a standalone manner or together to supply the desired value of load current. The noise contributed by the current source is very low in the entire current range. The fabrication of a low noise voltage preamplifier modified for bias dependent noise measurements and based on the existing design available in the MAT04 data sheet is also described.

Oscillators are key components of electronic systems. Undesired perturbations, i.e. noise, in practical electronic systems adversely affect the spectral and timing properties of oscillators resulting in phase noise, which is a key performance limiting factor, being a major contributor to bit-error-rate (BER) of RF communication systems, and creating synchronization problems in clocked and sampled-data systems. In this paper, we first present a theory and numerical methods for nonlinear perturbation and noise analysis of oscillators described by a system of differential-algebraic equations (DAEs), which extends our recent results on perturbation analysis of autonomous ordinary differential equations (ODEs). In developing the above theory, we rely on novel results we establish for linear periodically time-varying (LPTV) systems: Floquet theory for DAEs. We then use this nonlinear perturbation analysis to derive the stochastic characterization, including the resulting oscillator spectrum, of phase noise in oscillators due to colored (e.g., 1= f noise), as opposed to white, noise sources. The case of white noise sources has already been treated by us in a recent publication. The results of the theory developed in this work enabled us to implement a rigorous and effective analysis and design tool in a circuit simulator for low phase noise oscillator design.

The limits of the noise performance of detector readout front ends in CMOS technology have been studied. A theoretical minimal number of equivalent noise charge (ENC) that can be achieved by a CMOS technology is derived, taking both thermal noise and 1/f noise into account. Design criteria and techniques of CMOS readout front ends are presented so as to fully

Previous research in agricultural catchments showed that past inputs of nitrate continue to influence present observations and future characteristics of nitrate concentrations in stream water for a long period of time. This persistence manifests itself as a "memory effect" with a prolonged response of stream water nitrate levels to reductions of nitrate inputs on the catchment scale. The question we attempt to resolve is whether such a memory effect also exists in mountainous catchments with a snowmelt-dominated runoff regime. We analyzed long-term records (∼20 years) of nitrate-nitrogen concentrations measured in stream at three stations on the upper Váh River (Slovakia). Applying spectral analysis and detrended fluctuation analysis, we found a varying degree of persistence between the three analyzed sites. With increasing catchment area, the fluctuation scaling exponents generally increased from 0.77 to 0.93 (fluctuation exponents above 0.5 are usually considered as a proof of persistence while values close to 0.5 indicate "white" uncorrelated noise). The nitrate-nitrogen signals temporally scaled as a power-low function of frequency (1/f noise) with a strong annual seasonality. This increase in persistence might be attributable to the catchment areas upstream the sampling sites. These results have important implications for water quality management. In areas where reduction of nitrate in surface waters is imposed by legislation and regulatory measures, two catchments with different persistence properties may not respond to the same reduction of sources of nitrogen at the same rate.

This paper reviews recent research conducted at the University of Toronto on the development of CMOS transceivers aimed at operation in the 90-170-GHz range. Unique nanoscale CMOS issues related to millimeter-wave circuit design in the 65-nm node and beyond are addressed with an emphasis on transistor and top-level layout issues, low-voltage circuit topologies, and design flow. A Doppler transceiver and two receivers fabricated in a 65-nm GPLP CMOS technology are described, along with a single pole, double throw antenna switch with better than 5-dB insertion loss and 25-dB isolation in the entire 110-170-GHz band. The first receiver has an IQ architecture with a fundamental frequency voltage-controlled oscillator, and is intended for wideband passive imaging applications at 100 GHz. The measured noise figure and downconversion gain are 7-8 and 10.5 dB, respectively, while the 3-dB bandwidth extends from 85 to 100 GHz. The second receiver has double-sideband architecture, operates in the 135-145-GHz range (the highest for CMOS receivers), and features an 8-dB gain LNA, a double-balanced Gilbert cell mixer, and a dipole antenna. The 90-94-GHz Doppler transceiver, the highest frequency reported to date in CMOS, is intended for the remote monitoring of respiratory functions. A Doppler shift of 30 Hz, produced by a slow-moving (4.8 cm/s) target located at a distance of 1 m, was measured with a transmitter output power of approximately +2 dBm and a phase noise of 90 dBc/Hz at 1 MHz offset. The range correlation effect is demonstrated for the first time in CMOS by measuring the phase noise of the received baseband signal at 10-Hz offset, clearly indicating that 1 noise has been canceled and it does not pose a problem in short-range applications, where neither a phase-locked loop nor a frequency divider are needed.

The Riemann’s hypothesis (RH) states that the nontrivial zeros of the Riemann zeta-function are of the form sn =1/2 +iλn. Earlier work on the RH based on supersymmetric QM, whose potential was related to the Gauss-Jacobi theta series, allows to provide the proper framework to construct the well defined algorithm to compute the probability to find a zero (an infinity of zeros) in the critical line. Geometric probability theory furnishes the answer to the very difficult question whether the probability that the RH is true is indeed equal to unity or not. To test the validity of this geometric probabilistic framework to compute the probability if the RH is true, we apply it directly to the the hyperbolic sine function sinh(s) case which obeys a trivial analog of the RH (the HSRH). Its zeros are equally spaced in the imaginary axis sn =0+inπ. The geometric probability to find a zero (and an infinity of zeros) in the imaginary axis is exactly unity. We proceed with a fractal supersymmetr...

In the last decade, there has been an increasing interest in the analysis of energy level spectra and wave functions of nuclei, particles, atoms and other quantum many-body systems by means of statistical methods and random matrix ensembles. The concept of quantum chaos plays a central role for understanding the universal properties of the energy spectrum of quantum systems. Since these properties concern the whole spectrum, statistical methods become an essential tool. Besides random matrix theory, new theoretical developments making use of information theory, time series analysis, and the merging of thermodynamics and the semiclassical approximation are emphasized. Applications of these methods to quantum systems, especially to atomic nuclei, are reviewed. We focus on recent developments like the study of ''imperfect spectra'' to estimate the degree of symmetry breaking or the fraction of missing levels, the existence of chaos remnants in nuclear masses, the onset of chaos in nuclei, and advances in the comprehension of the Hamiltonian structure in many-body systems. Finally, some applications of statistical spectroscopy methods generated by many-body chaos and two-body random matrix ensembles are described, with emphasis on Gamow-Teller strength sums and beta decay rates for stellar evolution and supernovae.

Science is not merely the smooth progressive interaction of hypothesis, experiment and theory, although it sometimes has that form. More realistically the scientific study of any given complex phenomenon generates a number of explanations, from a variety of perspectives, that eventually requires synthesis to achieve a deep level of insight and understanding. One such synthesis has created the field of out-ofequilibrium statistical physics as applied to the understanding of complex dynamic networks. Over the past forty years the concept of complexity has undergone a metamorphosis. Complexity was originally seen as a consequence of memory in individual particle trajectories, in full agreement with a Hamiltonian picture of microscopic dynamics and, in principle, macroscopic dynamics could be derived from the microscopic Hamiltonian picture. The main difficulty in deriving macroscopic dynamics from microscopic dynamics is the need to take into account the actions of a very large number of components. The existence of events such as abrupt jumps, considered by the conventional continuous time random walk approach to describing complexity was never perceived as conflicting with the Hamiltonian view. Herein we review many of the reasons why this traditional Hamiltonian view of complexity is unsatisfactory. We show that as a result of technological advances, which make the observation of single elementary events possible, the definition of complexity has shifted from the conventional memory concept towards the action of non-Poisson

We investigated the dependence of llf noise on sheet resistance in poly crystalline resistors. The analysis is based on Hnoge's empirical relation. The llf noise is given by S,/R' = C.,/WLf. Experimental results on poly-Si are compared with results on poly-SiCe, Tisilicided poly-Si, metal Au-layers and RuO' based thick film resistors. This review shows that the results are similar and are well described by the relation: C., = KRSh with K = aqp (lowest value SxIO-" pm'1R).

As the scaling limit of silicon CMOS technology draws to an end, there is a critical need for novel materials and devices to drive the next generation of information processing. Graphene is one such promising candidate. Although graphene features exceptional intrinsic carrier mobility, thermal conductivity, and physical endurance, this two-dimensional material is quite sensitive to its environment as a result of its high surface-to-volume ratio. Variability effects become dominant and result in unreliable graphene devices. In order to realize high signal-to-noise ratio graphene devices for high-speed carbon-electronics, it is essential to investigate and minimize these variability
effects.

In this thesis, I present the preparation, design, and fabrication methods of single-layer and bilayer graphene sheet and graphene nanoribbon devices. Furthermore, I relate how these methods can contribute to the variability effects in graphene and graphene nanoribbons (GNR) devices while mentioning critical steps taken to minimize their influence. In order to understand how feasible graphene and GNR are for electronic devices, I investigate their device properties via electrical transport measurement and study their low-frequency (1/f) noise behaviors as a measure of how sensitive graphene and GNR are to their surroundings (e.g. surface traps near the graphene/SiO2 interface). Interestingly, graphene is shown to exhibit a noise behavior quite opposite to conventional semiconductor electronic materials – a noise minimum occurs when it is most resistive at its Dirac point. We also find that GNR devices show a direct correlation between the conductance fluctuations (noise) and the density-of-states of GNR. These results promote noise-metrology as a tool which can be used to probe the underlying band structure of quantum nanostructures.

In this paper, an integrated capacitive gyroscope fabricated by CMOS-MEMS technology is presented. The CMOS compatibility of the fabrication process enables full integration of the sensor with interface and signal conditioning circuitry on a single chip. The entire ...

C omplementary metal-oxide-semiconductor (CMOS) technology is dominant in the microelectronics industry for a wide range of applications, including analog, digital, RF, and sensor systems. The advantages of silicon CMOS technology compared to bipolar technology as well as transistors in other semiconductors is well-established. CMOS technology scaling has been a main drive for continuous progress in the silicon based semiconductor industry over the past two decades . The continuous downscaling of CMOS technologies towards nano feature size has increased the performance of integrated circuits considerably. However, one important limitation of MOSFET downscaling is an increase of 1/f noise (often referred to as low-frequency noise), since the 1/f noise increases as the reciprocal of the device area [2], . Furthermore, the development of nano-sized CMOS technologies has led to the observation of random telegraph signals (RTS) yielding large low frequency current fluctuations. Excessive low-frequency noise introduces serious limitations on the functionality of analog and digital circuits since it deteriorates the noise figure of operational amplifiers and A/D and D/A converters. Lowfrequency noise diminishes the signal-to-noise-ratio (SNR) of CMOS sensors, such as IR or CMOS image sensors [5] .

Narrow-band spectral components of ship radiated noise are of crucial importance for sonar operators in order to detect and classify possible targets. Classical spectral estimation techniques have been widely used to fulfill the requirements for narrow-band signal detection. However, classical methods may not be sufficient when signal-to-noise ratio is relatively low. In this paper we propose to utilize the subspace based multiple signal classification for the cavitation related narrow-band ship radiated noise detection. In addition we propose the use of fractional lower order statistics instead of second order statistics when the ship radiated noise exhibits an impulsive behavior leading to drifting apart from Gaussianity. We present the results of a real ship noise data gathered from the Strait of Istanbul. We also investigate and present the 1/f -type noise characteristics of a sample ship noise segment and discuss how we can use this information for robust estimation of cavitation related narrow-band ship noise spectrum.

The results of experimental and theoretical studies of low-frequency noise in wide-bandgap semiconductors and wide-band-gap semiconductor devices are reviewed. The unusual features of the low-frequency noise in these systems include an extremely low level of noise in Sic and SiCbased devices and a large difference in the noise level in GaN-based films and GaN-based field effect transistors (FETs) (with the noise being much smaller in GaN-based FETs). The authors also report on the generation-recombination noise in Sic and GaN-based materials and devices.

The defects related to the gate-dielectric in high-j-MOSFETs are studied using the 1/f noise technique. Three different types of gate electrodes were used for this purpose -poly-Si, metal (TiN/TaN) and fully Ni Silicided (FUSI) electrodes with Hf-based oxides as the gate dielectric layer. All the three types of devices show a specific behavior near the gate electrode-dielectric interface when the trap profiles are assessed using f · S I spectra. The tunneling depths were calculated and it was found that the high-j oxide (bulk) layers are being probed. From the drain current spectra S I vs. drain current I D of the various gate material devices at given depths, it may be inferred that the concentration of oxygen-vacancy-related defects can significantly influence the 1/f noise performance, which can explain the differences observed in noise between the gate electrodes. Comparison of FUSI gated devices, with various percentages of Hf in the dielectric layer, shows comparable noise levels (S VG ), indicating a minor dependence on Hf-content in the gate dielectric layer.

We calculate the two-qubit disentanglement due to classical random telegraph noise using the quasi-Hamiltonian method. This allows us to obtain analytical results even for strong coupling and mixed noise, important when the qubits have tunable working point. We determine when entanglement sudden death and revival occur as functions of qubit working point, noise coupling strength and initial state entanglement. For extended Werner states, we show that the concurrence is related to the difference of two functions: one is related to dephasing and the other longitudinal relaxation. A physical intepretation based on the generalized Bloch vector is given: revival only occurs for strongly-coupled noise and comes from the angular motion of the vector.

By using the continuous wavelet transform with Haar basis the second-order properties of the wavelet coefficients are derived for the random telegraph signal (RTS) and for the 1=f noise which is obtained by summation of many RTSs. The correlation structure of the Haar wavelet coefficients for these processes is found. For the wavelet spectrum of the 1=f noise some characteristics related to the distribution of the relaxation times of the RTS are derived. A statistical test based on the characterization of the time evolution of the scalogram is developed, which allows to detect non-stationarity in the times t's which compose the 1=f process and to identify the time scales of the relaxation times where the non-stationarity is localized. The proposed method allows to distinguish noise signals with 1=f power spectral density generated by RTSs, and thus gives informations on the origin of this type of 1=f noise which cannot be obtained using the Fourier transform or other methods based on second-order statistical analysis. The reported treatment is applied to both simulated and experimental signals. The present analysis is based on the McWhorter [1=f Noise and germanium surface properties, in: R.H. Kingstone (Ed.), Semiconductor Surface Physics, University of Pennsylvania Press, Philadelphia, PA, 1957, pp. 207-228] model of low frequency electric noise, and the obtained results are expected to prove especially useful for semiconductor devices. r

With the emerging interest in local field potentials (LFPs) as input signals for brain-machine interfaces, there is a need for integrated circuits capable of amplifying spikes and LFPs. A two-stage complementary metal-oxide semiconductor (CMOS) amplifier-filter has been implemented with 0.18-m CMOS for simultaneous, multimodal recording of extracellular unit spikes and LFPs. For the frequency tuning and the reduction of the 1 noise, it employs a switched-capacitor technique. The filter bandwidth is reconfigurable by using a different sampling clock frequency. The prototype amplifier has gains of 19.1 dB and 37.5 dB for low-pass only filter and cascaded filter, respectively. With a 100-kHz sampling frequency, the equivalent input noise spectral density is 38.8 nV/ Hz while the total power consumption is 69 W with a 1.6-V supply, including clock generation and biasing occupying an area of 44 148 m 2 .

The noise figure of an RF CMOS mixer is strongly affected by flicker noise. The noise figure can be improved using pMOS switch circuits, which insert current at the on/off crossing instants of the local oscillator switch stage because the circuits reduce the flicker noise injection. When it is applied to a conventional Gilbert mixer, the injection efficiency and linearity are degraded by the nonlinear parasitic capacitances of the pMOS switch circuits and the leakage through the parasitic path. We propose the pMOS switch circuits with an inductor, which tunes out the parasitic components at 2 and closes out the leakage path. The mixer fabricated in 0.13-m CMOS at 2.4-GHz center frequency has provided improved characteristics for linearity and noise figure.

In this paper, an integrated capacitive gyroscope fabricated by CMOS-MEMS technology is presented. The CMOS compatibility of the fabrication process enables full integration of the sensor with interface and signal conditioning circuitry on a single chip. The entire microstructure is single-crystal silicon based, resulting in large proof mass and good mechanical properties. Thus, high-resolution and high-robustness microgyroscopes can be obtained. With a resolution of about 0.01°/s/Hz 1/2 , the fabricated gyroscope chip is only as small as 1.5mm by 2mm including the sensing elements and integrated electronics. The robustness, light weight and high performance make this type of MEMS gyroscope very suitable for space navigation applications where payload is critical. The on-chip capacitive sensing circuitry employs chopper stabilization technique to minimize the influence of 1/f noise. The CMOS fabrication was performed through MOSIS by using the 4-metal TSMC 0.35µm CMOS process. The post-CMOS micromachining processing consists of only dry etch steps and uses the interconnect metal layers as etching masks. Single-crystal silicon (SCS) structures are produced by applying a backside etch and forming a 60µm-thick SCS membrane.

We report on the design and characterization of a new ASIC for the RatCAP, a head-mounted miniature PET scanner intended for neurological and behavioral studies of an awake rat. The ASIC is composed of 32 channels, each consisting of a charge sensitive preamplifier, a 5-bit programmable gain in the pole-zero network, a 3 rd order bipolar semi-Gaussian shaper (peaking time of 80 ns), and a timing and energy discriminator. The energy discriminator in each channel is used to arm the zero-crossing discriminator and can be programmed to use either a low energy threshold or an energy gating window. A 32-to-1 serial encoder is embedded to multiplex into a single output the timing information and channel address of every event. Finally, LVDS I/O were integrated on chip to minimize the digital noise on the read-out PCB.

The brain is probably the most interesting example of a complex network having 1/f1/f variability as determined through the analysis of EEG time series and magnetoencephalogram recordings. Herein we develop a theory of 1/f1/f noise of human cognition to explain the recent experimental observations that increasing the difficultly of cognitive tasks accelerates the transition from observed 1/f1/f noise to white noise in decision-making time series.

An integrated quadrature demodulator with an on-chip frequency divider is reported. The mixer consists of a transconductance stage, a passive current switching stage, and an operational amplifier output stage. A complementary input architecture has been used to increase the transconductance for a given bias current. The circuit is inductorless and is capable of operating over a broad frequency range. The chip was implemented in a 0.13m CMOS technology. From 700 MHz to 2.5 GHz, the demodulator achieves 35 dB of conversion voltage gain with 250-kHz IF bandwidth, a double-sideband NF of 10 dB with 9-33 kHz 1/f-noise corner. The measured IIP3 is +4 dBm for a 0.1-MHz IF frequency and +10 dBm for a 1-MHz IF frequency.

Reportamos ruido Shot, ruido Browniano (1/f2) y ruido 1/f en nano-películas de Dió- xido de Vanadio (V O2). Se observa que el ruido Shot tiene dependencia lineal con la corriente y a bajas frecuencias es prácticamente independiente de la frecuencia. El es- pectro del ruido Shot nos arroja detalles físicos acerca de la mecánica de transporte de electrones en la nano-película de VO2 así como acerca de la transición de fase del vanadio que al darse a temperaturas cercanas a las del ambiente, va a tener importantes aplicaciones. Para detectar esto, se alejó la muestra de ruido externo mediante un fil- tro pasa bajas y se utilizó un analizador de espectros para que arroje frecuencia contra amplitud de la señal directa sin análisis de Fourier.

Excess energy was measured with a Seebeck envelope calorimeter in an electrolytic system containing a 2 mm diameter Pd tube cathode. After about 50 hours of electrolysis, many power pulses (Pex < ∼0.5 W) and bursts (Pex > ∼0.5 W) of excess power Pex were observed. The distribution of the number of power pulses N(Pex) with definite excess power Pex plotted on a logarithmic scale is expressed as a straight line with a gradient ~ - 2 for Pex < ∼0.5 W showing the typical behavior of the 1/f noise. The distribution for Pex > ∼0.5 W deviates from this regularity. These characteristic behaviors are discussed in relation to complexity in the mechanism of the excess energy generation in the experimental system.

Phase noise is a topic of theoretical and practical interest in electronic circuits, as well as in other fields such as optics. Although progress has been made in understanding the phenomenon, there still remain significant gaps, both in its fundamental theory and in numerical techniques for its characterisation. In this paper, we develop a solid foundation for phase noise that is valid for any oscillator, regardless of operating mechanism. We establish novel results about the dynamics of stable nonlinear oscillators in the presence of perturbations, both deterministic and random. We obtain an exact, nonlinear equation for phase error, which we solve without approximations for random perturbations. This leads us to a precise characterisation of timing jitter and spectral dispersion, for computing which we develop efficient numerical methods. We demonstrate our techniques on practical electrical oscillators, and obtain good matches with measurements even at frequencies close to the carrier, where previous techniques break down. we present can be extended [1] for the MNA (Modified Nodal Analysis) formulation (i.e., DAE formulation) given by d=dt qx + f x = 0. 2 After any small disturbance that does not persist, the system asymptotically settles back to the original limit cycle. See [2] for a precise definition of this stability notion.

This paper examines the impact of an important geometrical parameter of FinFET devices, namely the fin width. From static and lowfrequency measurements on n-FinFETs (I-V, C-V and 1/f noise), transistor Figures of Merit in the near-threshold region (like threshold voltage, subthreshold slope, and drain induced barrier lowering); linear region (mobility, series resistance, 1/f noise) and saturation region (normalized transconductance, early voltage) are analyzed as a function of fin width. In the near-threshold region, fin width is seen to strongly impact the coupling between the back and front gates, while in the above threshold region, the most important impact of fin width is on the parasitic source/drain resistance, which affects different strong inversion parameters to different extents. With the help of analytical expressions, the impact of series resistance on these device parameters is studied, and the contribution from series resistance is de-embedded, enabling extraction of intrinsic device parameters. Significant differences are observed between the intrinsic and extrinsic parameters, especially for short and narrow devices, which also underlines the need for accounting for series resistance effects at every stage of FinFET characterization.

A model of 1/f noise in forward-biased p-n junction is suggested. The theory links current fluctuations to fluctuations of level occupancy in the density-of-states tail in the space charge region. The model is valid at forward biases for which the recombination current predominates. The 1/f (and 1/f-like) noise appears if the capture cross section of levels in the density-of-states tail decreases exponentially as the distance between a band edge and a level in the energy gap increases (multiphonon capture model). Analytical estimates for the frequency and current dependences of the 1/f noise are obtained.

Correlated double sampling provides an excellent method for the reduction of kTC noise in analog signal processing and has therefore found widespread use. One often hears the additional claim that correlated double sampling depresses low-frequency noise. Assessment of this claim requires theoretical derivation of the output power of the sampling circuit in terms of the input power. We provide this derivation for two different realizations of correlated double sampling that yield precisely equivalent power spectra. We find that noise suppression at low frequency depends to a great extent on system bandwidth since the input power spectrum aliases to frequencies separated by multiples of the clock frequency in the output spectrum.

In this paper, we describe a low-power low-voltage CMOS very low signal acquisition analog frontend of sensor electronic interfaces. These interfaces are mainly dedicated to biomedical implantable devices. In this work, we focus on the implantable bladder controller. Since the nerve signal has very low amplitude and low frequency, it is, at first fed to a low-voltage chopper amplifier to reduce the flicker (1/f ) noise and then amplified with a programmable gain high CMRR instrumentation amplifier. This is followed by an analog signal processing circuit to rectify and bin-integrate (RBI) the amplified signal. The resulting RBI is then converted to digital and transferred to the implant's central processor where information about bladder can be extracted. The numerous analog modules of the system have been implemented in CMOS 0.35 µm, 3.3 V technology. The design, simulation and measurement results of the proposed interface are presented. At supply voltage of 2.2 V the power dissipation is less than 1.4 mW, the input equivalent noise is 56 nV/ √ Hz and the error in RBI calculation is less than 0.15%.

This paper describes a 2.1-GHz CMOS front-end with a single-ended low noise amplifier (LNA) and a double balanced, current-driven passive mixer. The LNA features an on-chip transformer load to perform single-ended to differential conversion. Implemented in a 0.13 um CMOS process, it achieves 30 dB conversion gain, a low noise figure of 3.1 dB, a 40 kHz 1/f noise corner, an in-band IIP3 of -12 dBm and IIP2 better than 39 dBm, while consuming only 12 mW from a 1.5 V power supply.

Non-ergodic renewal processes have recently been shown by several authors to be insensitive to periodic perturbations, thereby apparently sanctioning the death of linear response, a building block of nonequilibrium statistical physics. We show that it is possible to go beyond the ``death of linear response" and establish a permanent correlation between an external stimulus and the response of a complex network generating non-ergodic renewal processes, by taking as stimulus a similar non-ergodic process. The ideal condition of 1/f-noise corresponds to a singularity that is expected to be relevant in several experimental conditions.

An integrated quadrature demodulator with an on-chip frequency divider is reported. The mixer consists of a transconductance stage, a passive current switching stage, and an operational amplifier output stage. A complementary input architecture has been used to increase the transconductance for a given bias current. The circuit is inductorless and is capable of operating over a broad frequency range. The chip was implemented in a 0.13m CMOS technology. From 700 MHz to 2.5 GHz, the demodulator achieves 35 dB of conversion voltage gain with 250-kHz IF bandwidth, a double-sideband NF of 10 dB with 9-33 kHz 1/f-noise corner. The measured IIP3 is +4 dBm for a 0.1-MHz IF frequency and +10 dBm for a 1-MHz IF frequency.

A new low-cost long-wavelength infrared bolometer camera system is under development. It is designed for use with an automatic vision algorithm system as a sensor to detect vulnerable road users in traffic. Looking 15 m in front of the vehicle it can in case of an unavoidable impact activate a brake assist system or other deployable protection system. To achieve our cost target below €100 for the sensor system we evaluate the required performance and can reduce the sensitivity to 150 mK and pixel resolution to 80 x 30. We address all the main cost drivers as sensor size and production yield along with vacuum packaging, optical components and large volume manufacturing technologies. The detector array is based on a new type of high performance thermistor material. Very thin Si/SiGe single crystal multi-layers are grown epitaxially. Due to the resulting valence barriers a high temperature coefficient of resistance is achieved (3.3%/K). Simultaneously, the high quality crystalline material provides very low 1/f-noise characteristics and uniform material properties. The thermistor material is transferred from the original substrate wafer to the read-out circuit using adhesive wafer bonding and subsequent thinning. Bolometer arrays can then be fabricated using industry standard MEMS process and materials. The inherently good detector performance allows us to reduce the vacuum requirement and we can implement wafer level vacuum packaging technology used in established automotive sensor fabrication. The optical design is reduced to a single lens camera. We develop a low cost molding process using a novel chalcogenide glass (GASIR®3) and integrate anti-reflective and anti-erosion properties using diamond like carbon coating.

A nonlinear field-effect transistor equivalent-circuit model is examined to identify the fundamental mechanisms that up-convert baseband 1 noise to near-carrier sideband noise when the device is operated in the large-signal regime. This model captures all physical noise sources and nonlinearities in the transistor, and thereby allows a general cause-and-effect treatment. The noise sources in the equivalent-circuit model are determined using low-frequency spectrum analyzer and microwave noise-figure meter data. Using the example of an AlGaN/GaN high electron-mobility transistor, the developed model correctly describes both the measured near-carrier sideband amplitude and phase noise simultaneously.

We show that dynamical systems with spatial degrees of freedom naturally evolve into a self-organized critical point. Flicker noise, or 1/f noise, can be identified with the dynamics of the critical state. This picture also yields insight into the origin of fractal objects.