Noise Cancellation Technique Research Articles

Design of 3.1 to 10.6 GHz ultra‐wideband flat gain LNA

SummaryIn this paper, a new ultra‐wideband low‐noise amplifier (LNA) is proposed. The proposed LNA has flat gain and low noise figure (NF) in the frequency range of 3.1 to 10.6 GHz. To obtain higher gain, cascode architecture is used. In this design, to have a lower NF, the noise cancellation technique applies to the cascode architecture. In addition, to have better matching at the input and output, active feedback and matching transistors are used, which also leads to better NF. To have flat gain, RLC load is used. In the proposed LNA, only one inductor is used, which leads to the smaller chip area. The proposed circuit is designed in 90 nm CMOS technology. The simulation shows NF of between 1.62 and 2.1 dB, flat gain between 11.9 and 12 dB and power consumption of 11.72 mW in the frequency range of 3.1 to 10.6 GHz. The simulation results support the theoretical predictions. Copyright © 2017 John Wiley & Sons, Ltd.

Hybrid Nelder-Mead search based optimal Least Mean Square algorithms for heart and lung sound separation

Algorithms for separation of heart sounds from background lung sound noises are vital for accurate diagnosis of heart diseases. In this paper, an improved adaptive noise cancellation technique based on the Least Mean Square (LMS) algorithm is used to separate heart sounds from lung sounds. The step size parameter in the LMS algorithm is optimally chosen using a hybrid Nelder-Mead (H-NM) optimization algorithm. The NM algorithm is initialized with a good initial solution by using computationally cheap random search to compute a rough estimate of the global minimum. Initialization of the NM algorithm with a good initial guess avoided convergence to shallow local minima and improved the quality of the final solution. The effects of using two state-of-the-arts biologically inspired heuristic optimization algorithms instead of the H-NM algorithm and three variants of the standard LMS algorithm are investigated. The correlation coefficient between the ideal and filtered heart sound signal and running time-complexity of different algorithms are taken as the metric for comparison of different heart sound separation approaches. Simulation results indicate that the approach presented in this paper performs significantly better than a variety of alternate approaches on heart sound separation problems.

Inductorless CMOS Low Noise Amplifier for Multiband Application in 0.1–1.2 GHz

A 0.18 µm CMOS low noise amplifier (LNA) by utilizing noise-canceling technique was designed and implemented in this paper. Current-reuse and self-bias techniques were used in the first stage to achieve input matching and reduce power consumption. The core size of the proposed CMOS LNA circuit without inductor was only 128 µm × 226 µm. The measured power gain and noise figure of the proposed LNA were 20.6 and 1.9 dB, respectively. The 3-dB bandwidth covers frequency from 0.1 to 1.2 GHz. When the chip was operated at a supply voltage of 1.8 V, it consumed 25.69 mW. The high performance of the proposed LNA makes it suitable for multi-standard low-cost receiver front-ends within the above frequency range.

A Correlation Study on Motion Artifact using Photodiode and Three Axis Accelerometer Signals

Objectives:The three-axis accelerometer used to reflect the Motion Artifact (MA) implemented in the Adaptive Noise Cancellation (ANC) technique has failed to provide the required MA for accurate processing. This study investigates the validity of using a Covered Photodetector (CPD) for MA detection to unify the sources of generated desired and MA signals to avoid electronic noise differences. Methods/Statistical Analysis:The two devices were fastened together and exposed to various kinds of motions. The Amplitude Fluctuations (AFs) responding in the time domain and the Linear Correlation Coefficient (r) were observed. Findings:Confirmed the proposed approach validity by pointing a rapprochement in AFs. The calculated r was0.999 in asteady state while in motion states rangesfrom 0.998 to 0.794 according to movement changes. Application/Improvements: Implementing such concept for Photoplethysmography signal processing within ANC leads to a curate critical medical diagnosis at a lower cost.

Low power ultra wide-band balun LNA using noise cancellation and current-reuse techniques

A low power, single to differential (balun) low noise amplifier (LNA) using noise cancellation and current re-use techniques is presented for ultra wide-band applications. An upsurge balun LNA is designed using UMC 0.18-μm RF CMOS technology with an emphasis on the covenant between gain, bandwidth and power dissipation. The proposed balun exerts a differential stage on top of common gate-common source (CG-CS) stage. A CG-CS stage exploits amalgamation of CG stage (for wide-band impedance matching) and CS to curtail gain and phase imbalance, while simultaneously negating the noise and distortion of input matching transistor. The escalation of bandwidth has been accomplished using staggered tuning on CG-CS and differential stages. The stacked differential amplifier does cancellation of self noise as well as supply noise. The proposed UWB balun LNA achieves 14dB voltage gain with agreeable input reverse isolation (S11) of <-8dB over the frequency range of 3.19–8.8GHz. The minimum noise figure of 3.9dB and P1dB of −10.5dBm while exhausting 3.8mW from 1.2V supply. The superlative performance of balun LNA is accomplished between 3.19 and 8.8GHz with gain and phase errors below 0.2dB and 0.40 respectively. The layout occupying 0.77mm2 area. The overall pre and post layout simulations of proposed LNA shows admissible agreement with theoretical predictions.

Analysis and Design of Inductorless Wideband Low-Noise Amplifier With Noise Cancellation Technique

This paper deals with the fabrication of an inductorless wideband low-noise amplifier (LNA). The LNA includes two branches in parallel: a common-source (CS) path and a common-gate (CG) path. The CS path is responsible for providing enough power gain, while the CG path is used to achieve the input impedance matching. To eliminate the noise contribution of the CG path, the noise cancellation technique is applied. Therefore, the overall noise figure (NF) is improved. The phase mismatch between the two paths is also quantitatively analyzed to investigate its effect on gain and NF. The analytical results agree well with the simulation results. The LNA has been fabricated by a commercial 0.18- $\mu \text{m}$ CMOS process. The measurement results show that the LNA has achieved a maximum gain of 14.5 dB with 1.7-GHz 3-dB gain bandwidth and a minimum NF of 3 dB. The tested input 1-dB gain compression point (IP $_{{\text {1 dB}}}$ ) is −10.4 dBm at 1 GHz and the input third-order intercept point is 0.25 dBm. With 1.8-V supply, the LNA draws only 6-mA dc current.

Golay-Correlator Window-Based Noise Cancellation Equalization Technique for 60-GHz Wireless OFDM/SC Receiver

In this paper, a Golay-correlator window-based noise cancellation (GC-WNC) technique with frequency-domain equalizer (FDE) is proposed. The GC-WNC is a cooperative scheme in the time and frequency domains to combat the multipath effect in nonline-of-sight (NLOS) and LOS channels for orthogonal frequency-division multiplexing (OFDM) and single-carrier mode baseband inner receiver over 60-GHz environment for IEEE 802.15.3c and 802.11ad. According to mean-square error criterion, WNC approach is to minimize the estimation error between the ideal and the estimated channel frequency response (CFR) on each subchannel. The CFR is precisely obtained as coefficients of FDE to compensate multipath effect even in NLOS channel. The GC-WNC FDE with 8X-parallelism is designed as a part of digital baseband inner receiver with 40-nm CMOS general-purpose process. Because of area restriction of tape-out chip, only the OFDM mode is fabricated in the chip. The GC-WNC FDE has an equivalent gate count of 230k occupying 11.3% of the baseband inner receiver. Based on the chip measurement results, the baseband inner receiver with GC-WNC FDE provides 24-Gb/s throughput with 500-MHz operating clock and 0.94 V supply voltage. The power consumption of GC-WNC FDE is 69.79 mW. The baseband inner receiver with GC-WNC FDE can deliver a multigigabit per second throughput with the power dissipation of 2.91/2.26 mW/Gb/s at 500-/330-MHz operating clock for the OFDM mode.

The BLIXER, Integrated Balun-LNA-Mixer for ZigBee Application

Objectives: The main objective of this paper is to design a Blixer using noise-cancelling technique and balun –LNA-Mixer for better performance. Methods: As studied in literature of mixers, it shows they have less bandwidth disadvantage. This paper is concentrated to realize a wide bandwidth mixer by keeping the real part of the impedance of all RF nodes low, and using this mixer there is no capacitive loading problem. Findings: By avoiding use of inductors, the on chip size of circuit will be reduced and also the bandwidth extension requirement is fulfilled. This gives less DC-voltage drop after IF filtering. The design is implemented and simulated using Advanced Design System tool in CMOS 0.18um technology. The noise figure of the final BLIXER is obtained as 0.6dB and that of LNA is less than 2dB. This results are one of the best seen for a BLIXER. Applications: This design is well suited for wideband ZigBee receiver in wireless communication systems.

Feasibility analysis of heart rate monitoring of construction workers using a photoplethysmography (PPG) sensor embedded in a wristband-type activity tracker

Abstract With increasing concerns regarding occupational safety and health, managing excessive physical workloads of workers is critical to prevent workers' fatigue, injuries, errors, or accidents at physically demanding workplaces such as construction. In this regard, heart rate (HR) is an effective physiological indicator of workers' physical demands. Currently, off-the-shelf wearable activity trackers (e.g., wristband-type) can monitor a worker's HR with its embedded photoplethysmography (PPG) sensor. However, PPG signals can be highly affected by signal noises resulted from user's movements, and thus the exact HR extraction from a wristband-type PPG may not be sufficiently accurate during intensive construction tasks. In this paper, we investigate the accuracy of a PPG sensor embedded in a wristband-type tracker to see if it can be used for construction. Through field data collection from seven construction workers, we conduct a comparative HR analysis between a PPG sensor and an electrocardiography (ECG) sensor in a chest strap used as ground truth. The results show that a PPG-based HR sensor in a wristband-type activity tracker has a potential for practicable HR monitoring of construction workers with 4.79% of mean-average-percentage-error (MAPE) and 0.85 of correlation coefficient for whole datasets (4.44%, 4.52%, and 5.33% of MAPEs and 0.89, 0.70, and 0.61 of correlation coefficients during light works with 110 bpm of HRs, respectively). Because there is still room for improvement of the accuracy, particularly during heavy works, we also investigate the factors affecting the accuracy of HR monitoring using inequality statistics. From this secondary investigation, we found the major sources of error including noises from motion artifacts. With advanced noise-cancellation techniques, it is expected that that field HR monitoring using wearable activity trackers can be used to evaluate worker's physical demands from diverse construction tasks in a non-intrusive and affordable way. As a result, our work will help manage excessive workloads (e.g., flexing work/rest plans) so that a worker can sustain his/her given tasks during working time in a safer and healthier way.

Extended Kalman smoother with differential evolution technique for denoising of ECG signal.

Electrocardiogram (ECG) signal gives a lot of information on the physiology of heart. In reality, noise from various sources interfere with the ECG signal. To get the correct information on physiology of the heart, noise cancellation of the ECG signal is required. In this paper, the effectiveness of extended Kalman smoother (EKS) with the differential evolution (DE) technique for noise cancellation of the ECG signal is investigated. DE is used as an automatic parameter selection method for the selection of ten optimized components of the ECG signal, and those are used to create the ECG signal according to the real ECG signal. These parameters are used by the EKS for the development of the state equation and also for initialization of the parameters of EKS. EKS framework is used for denoising the ECG signal from the single channel. The effectiveness of proposed noise cancellation technique has been evaluated by adding white, colored Gaussian noise and real muscle artifact noise at different SNR to some visually clean ECG signals from the MIT-BIH arrhythmia database. The proposed noise cancellation technique of ECG signal shows better signal to noise ratio (SNR) improvement, lesser mean square error (MSE) and percent of distortion (PRD) compared to other well-known methods.

Dissemination of optical-comb-based ultra-broadband frequency reference through a fiber network.

We disseminated an ultra-broadband optical frequency reference based on a femtosecond (fs)-laser optical comb through a kilometer-scale fiber link. Its spectrum ranged from 1160 nm to 2180 nm without additional fs-laser combs at the end of the link. By employing a fiber-induced phase noise cancellation technique, the linewidth and fractional frequency instability attained for all disseminated comb modes were of order 1 Hz and 10-18 in a 5000 s averaging time. The ultra-broad optical frequency reference, for which absolute frequency is traceable to Japan Standard Time, was applied in the frequency stabilization of an injection-seeded Q-switched 2051 nm pulse laser for a coherent light detection and ranging LIDAR system.

A CMOS low noise transconductance amplifier for 1–6 GHz bands

The linearity and noise requirements in multi-band multi-standard applications make the design of RF CMOS circuits a very challenging task. A low noise transconductance amplifier (LNTA) in 130 nm CMOS technology that operates between 1 and 6 GHz is presented. The LNTA is based on a shunt-feedback (SFB) amplifier with current-reuse scheme and employing the noise-canceling technique used in low-noise amplifier designs for wideband input matching. Two versions of the LNTA were designed in a 130 nm CMOS process and occupy 0.038 and 0.014 mm2 of silicon area while consuming just 9.1 and 7.94 mW, respectively. The second version is an inductorless, smaller, and optimized version of the first one. Post-layout simulations in the temperature range of ź40 to 125 °C show a good trade-off between noise and power-consumption across the frequency span with an average noise figure of 3.8 dB and a minimum transconductance of 41.5 mS over the entire band. Performance variations were estimated at 2 GHz with Monte Carlo analysis.

A 2.0–5.5 GHz Wide Bandwidth Ring-Based Digital Fractional-N PLL With Extended Range Multi-Modulus Divider

Phase noise performance of ring oscillator based digital fractional-N phase-locked loops (FNPLLs) is severely compromised by conflicting bandwidth requirements to simultaneously suppress oscillator phase and quantization noise introduced by the time-to-digital converter (TDC), $\Delta \Sigma $ fractional divider, and digital-to-analog converter (DAC). As a consequence, their figure-of-merit (FoMJ) that quantifies the power–jitter tradeoff is at least 25 dB worse than their LC-oscillator-based FNPLL counterparts. This paper seeks to close this performance gap by extending PLL bandwidth (BW) using quantization noise cancellation techniques and by employing a dual-path digital loop filter to suppress the detrimental impact of DAC quantization noise. Fabricated in 65 nm CMOS process, the proposed FNPLL operates over a wide frequency range of 2.0–5.5 GHz using a modified extended range multi-modulus divider with seamless switching. The proposed digital FNPLL achieves 1.9 psrms integrated jitter while consuming only 4 mW at 5 GHz output. The measured in-band phase noise is better than −96 dBc/Hz at 1 MHz offset. The proposed FNPLL achieves wide BW up to 6 MHz using a 50 MHz reference and its FoMJ is −228.5 dB, which is the best among all reported ring-based FNPLLs.

Controlling kilometre-scale interferometric detectors for gravitational wave astronomy: Active phase noise cancellation using EOMs

The second generation of Gravitational waves detectors are kilometric Michelson interferometers with additional recycling Fabry–Perot cavities on the arms and ​the addition of two more recycling cavities to enhance their sensitivity, with the particularity that all the mirrors are suspended. In order to control them a new technique, based on the use of auxiliary lasers, has been developed to bring the interferometer to its working point, with all the cavities on their resonance, in an adiabatic way. The implementation of this technique in Advanced Virgo is under preparation and the propagation of a stable laser through a 3-km optical fibre is one of the most problematic issues. A new technique of active phase noise cancellation based on the use of Electro Optical Modulators has been developed, and a first prototype has been successfully tested.

Adaptive noise cancellation based harmonic elimination in grid integrated photovoltaic system

In this study, an adaptive noise cancellation technique is applied to eliminate harmonics in a grid integrated solar photovoltaic (PV) system under non-linear load. A neuron is used to extract a fundamental component from polluted load currents. The proposed system serves multiple functions, as improvement of power quality at point of common coupling including other connected non-linear loads, extraction of maximum power from a given PV array and feeding extracted solar power into the distribution system. The multiple functionality at a time helps in fast recovery of cost of power converters. The proposed control algorithm is based on adaptive detection of fundamental component. The proposed control algorithm presents an improved sensitivity for fast load changes. This proposed two-stage PV power generating system is designed, modelled and tested to provide the solutions of several power quality problems in three-phase four-wire distribution system.

Reduction of Motion Artifacts and Improvement of R Peak Detecting Accuracy Using Adjacent Non-Intrusive ECG Sensors.

Non-intrusive electrocardiogram (ECG) monitoring has many advantages: easy to measure and apply in daily life. However, motion noise in the measured signal is the major problem of non-intrusive measurement. This paper proposes a method to reduce the noise and to detect the R peaks of ECG in a stable manner in a sitting arrangement using non-intrusive sensors. The method utilizes two capacitive ECG sensors (cECGs) to measure ECG, and another two cECGs located adjacent to the sensors for ECG are added to obtain the information on motion. Then, active noise cancellation technique and the motion information are used to reduce motion noise. To verify the proposed method, ECG was measured indoors and during driving, and the accuracy of the detected R peaks was compared. After applying the method, the sum of sensitivity and positive predictivity increased 8.39% on average and 26.26% maximally in the data. Based on the results, it was confirmed that the motion noise was reduced and that more reliable R peak positions could be obtained by the proposed method. The robustness of the new ECG measurement method will elicit benefits to various health care systems that require noninvasive heart rate or heart rate variability measurements.

Offset calibration technique for capacitive transimpedance amplifier used in uncooled infrared detection

This paper presents a novel readout circuit of uncooled, bolometer-based, focal plane arrays (FPAs). The offset and flicker noise are the design challenges of microbolometer readout circuits (ROCs). The ROC is not only required to apply careful noise cancellation techniques, but also to be insensitive to process and supply voltage variations. The proposed circuit involves a new offset cancellation technique which overcomes process variations, noise, random, and systematic offset.

Wideband balun‐LNA exploiting noise cancellation and compensation technique

A wideband single-ended input, differential output balun-LNA is proposed for multi-standard wireless applications between 10 MHz and 3 GHz. The common-gate (CG) input stage in combination with a noise cancellation topology is adopted for wideband input matching and low-noise figure. An output stage with g m ″ compensation technique is utilised to promote the limited gain of the CG input stage, and obtain an optimised linearity performance. Realised in TSMC 180 nm RF CMOS process, the LNA provides a gain of 19.7 dB, a maximum input third-order interception point of 1.13 dBm, and a minimum NF AQ1 of 1.93 dB over a 3 dB bandwidth from 10 MHz to 1.7 GHz. Meanwhile, the proposed LNA shows good measured performance over the frequency band of 1.7–3 GHz.

Noise Filtering for Wall-Pressure Fluctuations in Measurements Around a Cylinder With Laminar and Turbulent Flow Separation

This paper proposes two different noise cancellation techniques for cleaning wall-pressure fluctuations signals. These fluctuations are measured around a circular cylinder with laminar and turbulent flow separation. The noise cancellation techniques are based on Wiener and adaptive filters and use the signals of pressure transducers mounted in a cross section of the cylinder and the signal of a free-field sensor opportunely located upstream. First, synthetic signals are used in order to validate the procedure. Then, both techniques are applied to the experimental data. Specific attention is paid to the filter order, optimized by a method introduced in this paper. Both filter types showed a selective behavior preserving the essence of the fluid dynamic phenomena characterizing the flow fields at each Reynolds number tested, especially when laminar separation occurs.

A 0.1–8 GHz wideband low-noise amplifier exploiting gain-enhanced noise-cancelling technique

A 0.1–8 GHz wideband low-noise amplifier exploiting gain-enhanced noise-cancelling technique