Jitter Measurement Research Articles

Absolute measurement of sampling jitter in audio equipment.

This study proposes a method for analyzing sampling jitter in audio equipment based on the time-domain analysis, considering the temporal fluctuations of the zero-crossing points in the recorded sinusoidal waves to characterize the jitter. This method enabled the separate evaluation of jitter in an audio player from those in audio recorders when the same playback signal is simultaneously fed into two audio recorders. The experiments were conducted using commercially available portable devices with a maximum sampling rate of 192 000 samples per second. The results demonstrated that jitter values on the order of a few tens of picoseconds can be identified in an audio player. Moreover, the proposed method enabled the separation of jitter from phase-independent noise utilizing the left and right channels of the audio equipment. As such, this method is applicable for performance evaluation of audio equipment, signal generators, and clock sources.

Rain conditions effect the transmission of Streaming video data on Aeromodelling

Streaming is the process of sending data continuously or continuously that be broadcast over the internet. FPV (First-person view) is a method used to control radio control vehicles from the pilot. Analysis of live video streaming service on FPV aeromodelling with standard configurations to determine the maximum results for live video streaming service on FPV aeromodelling. Distance measurements and environmental conditions are also necessary to determine the performance of live video streaming. Then performed a Quality of Service (QoS) analysis, including measurement of delay, jitter, and throughput using Wireshark. From the tests that have been carried out, the comparison of the best value between the measurement of data delay with a value of 0.0085 m/s, for a jitter of 20.294 m/s and a throughput of 0.009 m/s is obtained, all of which are in accordance with the standards recommended by ITU-T, so that the overall QoS obtained gives sufficient results

A Process-Adaptive Cell-Based Cyclic Time-to-Digital Converter Using One-Way Varactor Cells

Time-to-digital converters (TDCs) are commonly used for on-chip instrumentation. This article proposes a low-cost Cyclic-TDC with several distinct features. It can adapt to the process variation to maintain a fine resolution across all process corners. This is made possible by a so-called one-way varactor cell (OWVC) and an autonomous calibration process. In addition, it supports easy process migration. Last but not least, we show how it can be used for clock jitter measurement with reduced output uncertainty. Simulation results using a 90-nm CMOS process and a 40-nm CMOS process are used to demonstrate their advantages.

High-resolution timing jitter measurement based on the photonics time stretch technique.

High-resolution jitter measurement is essential for the next generation of electronic communications and sensor systems. However, most electrical timing jitter measurement equipment has a low resolution because of the limitations of electronic processing accuracy. Meanwhile, photonics-based jitter measurement methods have a higher resolution but cannot measure the widely used electrical signals. This work proposes a potential high-resolution jitter measurement method for electrical signals based on the photonics time stretch technique. The jitter information can be magnified in the optical domain and then measured by electrical equipment. The experimental results demonstrate that the jitter of an electrical pulse is magnified from 59.02 ps to 663.29 ps when the magnification factor is 11.24.

The dependence of timing jitter of superconducting nanowire single-photon detectors on the multi-layer sample design and slew rate.

We investigated the timing jitter of superconducting nanowire single-photon detectors (SNSPDs) and found a strong dependence on the detector response. By varying the multi-layer structure, we observed changes in pulse shape which are attributed to capacitive behaviour affecting the pulse heights, rise times and consequently timing jitter. Moreover, we developed a technique to predict the timing jitter of a single device within certain limits by capturing only a single detector pulse, eliminating the need for detailed jitter measurement using a pulsed laser when a rough estimate of the timing jitter is sufficient.

Commissioning and first results of an x-band LLRF system for TEX test facility at LNF-INFN

In the framework of LATINO project (Laboratory in Advanced Technologies for INnOvation) funded by Lazio regional government, the commissioning of the TEst stand for X-band (TEX) facility has started in 2021 at Frascati National Laboratories of INFN. Born as a collaboration with CERN to test high gradient accelerating structures, during 2022 TEX aims at feeding the first EuPRAXIA@SPARC_LAB X-band structure prototype. During 2021 the commissioning has been successfully carried out up to 48 MW. The power unit is driven by an X-band low level RF system, that employs a commercial S-band (2.856 GHz) Libera digital LLRF (manufactured by Instrumentation Technologies), with an up/down conversion stage and a reference generation and distribution system able to produce coherent frequencies for the American S-band and European X-band (11.994 GHz), both designed and realized at LNF. The performance of the system, with a particular focus on amplitude and phase resolution, together with klystron and driver amplifier jitter measurements, will be reviewed in this paper. Moreover, considerations on its suitability and main limitations in view of EuPRAXIA@SPARC_LAB project will be discussed.

Design of a high‐performance advanced phase locked loop with high stability external loop filter

For this task, an improved phase locked loop (PLL) was developed using a more sophisticated phase-frequency detector with multiband flexible dividers that provide enhanced frequency resolution, a better spectrum, and a better output signal. Great timing jitter was the problem for the old PLL designs because of the unbalanced frequency transfer function caused by the voltage-controlled oscillator and noise introduced by increases in supply voltage. A new design was suggested for the phase-frequency detector (PFD) such that PLL lock times are reduced while maintaining a low level of phase jitter. This way, they used fewer transistors, used less power, and had lower propagation holdup and smaller size compared to static PFDs. Additionally, forward ring voltage-controlled oscillator may improve the resolution of frequency and phase variation errors owing to supply noise by balancing driving force ratios in the feed-forward and feedback paths. Additionally, there is a dynamic sense flexible divider with several bands for separating special divisions (divide-by-47 and divide-by-48) that lacks a few extra flip-flops which save considerable power and improves the frequency difficulties of the multi-band divider. The advanced phase locked loop (ADPLL) has integrated phase and frequency errors, where the ADPLL excels. The supply noise is decreased by three reference clock cycles and the effect is that the measurement of jitter is better. Advanced Phase Locked Loop oscillates at frequencies ranging from 500 MHz to 4 GHz. A root mean square jitter of 1.29 ps is observed at 1 GHz. Our PLL is rated at 92.1-μW, with power used at 0.31 mW/GHz. The aim of this article is to design a 180 mm CMOS-based PLL circuit with a 400 MHz clock and a 0.65 V supply at a fast, dynamic phase frequency detector for resolution and stability.

ADC Clock Jitter Measurement Based on Simple Coherent Sampling Algorithm

In a high-speed sampling system, the clock jitter of analog-to-digital converters (ADCs) will greatly affect its sampling accuracy, leading to the reduction of the signal-to-noise ratio (SNR) of the system output. Therefore, it is necessary to compensate the sampling results to reduce the sampling error caused by clock jitter by measuring the distribution sequence of jitter. In this paper, the influence of clock jitter on the ADC sampling process is analyzed, and an ADC clock jitter measurement scheme based on a simple coherent sampling algorithm is investigated. This scheme can accurately measure the distribution sequence of clock jitter, and has the characteristics of low computational complexity and high precision. The simulation results show that this algorithm can accurately measure the clock jitter sequence with root-mean-square (RMS) greater than 5ps when the amplitude noise of the input signal is greater than 35dB, and the relative error is less than 5%.

Capturing vocal fry: Understanding the acoustic and perceptual differences in elicited and naturally produced vocal fry

Vocal fry, used frequently by both men and women, is often associated with negative stereotypes of young women. This study examines how different ways of eliciting vocal fry affects acoustic properties as well as listener perceptions of speech. Stimuli in previous studies have been obtained from actors who were presented with obvious examples of fry from media sources and were then instructed to produce speech with vocal fry. This method of eliciting fry may introduce other vocal characteristics that activate stereotypes. We obtained natural stimuli by asking speakers to read passages with no instructions about vocal fry and created a corpus of acoustic and prosodic data about naturalistic fry. We then recorded actors who listened to naturally-produced examples of vocal fry. We compared the acoustic characteristics of low and high fry speech from our naturally-produced utterances, our actors, and stimuli collected by Anderson et al. (2014). Elicited fry (from both studies) differed when compared to naturally-produced fry. Additionally, elicited fry in our study differed from that of Anderson et al on jitter and other measures. The three sets of stimuli were used to replicate and extend Anderson and colleagues’ study on listener perceptions of men and women using vocal fry.

Automatic jitter measurement in needle-detected motor unit potential trains

In an active motor unit (MU), the time intervals between the firings of its muscle fibers vary across successive MU activations. This variability is called jitter and is increased in pathological processes that affect the neuromuscular junctions or terminal axonal segments of MUs. Traditionally, jitter has been measured using single fiber electrodes (SFEs) and a difficult and subjective manual technique. SFEs are expensive and reused, implying a potential risk of patient infection; so, they are being gradually substituted by safer, disposable, concentric needle electrodes (CNEs). As CNEs are larger, voltage contributions from individual fibers of a MU are more difficult to detect, making jitter measurement more difficult. This paper presents an automatic method to estimate jitter from trains of motor unit potentials (MUPs), for both SFE and CNE records. For a MUP train, segments of MUPs generated by single muscle fibers (SF MUP segments) are found and jitter is measured between pairs of these segments. Segments whose estimated jitter values are not reliable, according to several SF MUP segment characteristics, are excluded. The method has been tested in several simulation studies that use mathematical models of muscle fiber potentials. The results are very satisfactory in terms of jitter estimation error (less than 10% in most of the cases studied) and mean number of valid jitter estimates obtained per simulated train (greater than 1.0 in many of the cases and less than 0.5 only in the most complicated). A preliminary study with real signals was also performed, using 19 MUP trains from 3 neuropathic patients. Jitter measurements obtained by the automatic method were compared with those extracted from a commercial system (Keypoint) and the edition and supervision of an expert electromyographer. From these measurements 63% were taken from equivalent interval pair sites within the time span of the MUP trains and, as such, were considered as compatible measurements. Differences in jitter of these compatible measurements were very low (mean value of 1.3 μs, mean of absolute differences of 2.97 μs, 25% and 75% percentile intervals of −0.85 and 3.82 μs, respectively). Although new tests with larger number of real recordings are still required, the method seems promising for clinical practice.

Yoctosecond Timing Jitter Sensitivity in Tightly Synchronized Mode-Locked Ti:Sapphire Lasers

Higher sensitivity in timing jitter measurement has great importance in studies related to precise measurements. Timing jitter noise floors contribute one of the main parts in existing measurements. In this article, a phase error signal is obtained by superposition of outputs of two optical heterodyne discrimination apparatus to suppress the noise floor. Excess phase noise of the electrical amplifier is avoided. We demonstrate 2.6 × 10−14 fs2/Hz (~160 ys/√Hz) timing jitter noise floor between two identical 99 MHz repetition-rate mode-locked Ti:sapphire lasers after their repetition rates are tightly synchronized. The performance is extensible to reach an integrated timing jitter resolution of one attosecond.

Concentric needle jitter: Reference values in stimulated Tibialis Anterior muscle.

Calculating the reference values for jitter parameters utilizing a disposable concentric needle have been already done for the most often tested muscles. Jitter, expressed as the mean consecutive difference (MCD), was measured in the Tibialis Anterior (TA), not routinely tested muscle. Jitter measurement was taken using the intramuscular microaxonal stimulation technique in 32 healthy subjects. The mean MCD and the mean MCD of the 27th value from the 32 subjects had a normal distribution and were 19.79 ± 2.72 μs and 26.88 ± 3.56 μs, respectively. The suggested limit for the mean MCD is ≥ 26 μs and for the individual values is > 34 μs.

Classification of Dysphonic Voices in Parkinson's Disease with Semi-Supervised Competitive Learning Algorithm.

This article proposes a novel semi-supervised competitive learning (SSCL) algorithm for vocal pattern classifications in Parkinson’s disease (PD). The acoustic parameters of voice records were grouped into the families of jitter, shimmer, harmonic-to-noise, frequency, and nonlinear measures, respectively. The linear correlations were computed within each acoustic parameter family. According to the correlation matrix results, the jitter, shimmer, and harmonic-to-noise parameters presented as highly correlated in terms of Pearson’s correlation coefficients. Then, the principal component analysis (PCA) technique was implemented to eliminate the redundant dimensions of the acoustic parameters for each family. The Mann–Whitney–Wilcoxon hypothesis test was used to evaluate the significant difference of the PCA-projected features between the healthy subjects and PD patients. Eight dominant PCA-projected features were selected based on the eigenvalue threshold criterion and the statistical significance level (p < 0.05) of the hypothesis test. The SSCL algorithm proposed in this paper included the procedures of the competitive prototype seed selection, K-means optimization, and the nearest neighbor classifications. The pattern classification experimental results showed that the proposed SSCL method can provide the excellent diagnostic performances in terms of accuracy (0.838), recall (0.825), specificity (0.85), precision (0.846), F-score (0.835), Matthews correlation coefficient (0.675), area under the receiver operating characteristic curve (0.939), and Kappa coefficient (0.675), which were consistently better than those results of conventional KNN or SVM classifiers.

A 100-MHz 3.352-mW 8-bit shift register using low-power DETFF using 90-nm CMOS process

ABSTRACT By keeping the very same transmission rate, a scheme is provided by DETFF (double-edge triggered flip-flops) for power dissipation reduction. As a result, they are suitable for use as shift registers. This investigation discussed various previous DETFF designs and demonstrated a new DETFF circuit applied to construct an 8-bit low-power shift register. This study makes a significant contribution by using two parallel data paths that operate in a single clock’s opposing phases where an inverted input trigger is unnecessary. TSMC 90-nm complementary metal-oxide semiconductor (CMOS) technology was used to implement the proposed shift register. Comparing the proposed DETFF with prior works, it has fewer transistor counts since the negated input trigger and auxiliary devices were removed, resulting in lower area cost and lower power dissipation. At 100 MHz clock frequency and lower supply voltage of 1.0 V, it demonstrates a power consumption of 3.352 mW on silicon, making it suitable for low-power applications. Lastly, it has the best performance compared with prior works speaking of larger scale, as demonstrated by the chip’s functionality and jitter measurement at the maximum frequency of 200 MHz.

Influence of time shifting of single muscle fiber potentials (SFPs) on jitter values measured using concentric needle electrode – a simulation study

ObjectivesThe aim of this simulation study was to evaluate the resulting value of jitter measured from a simulated examination recording and to analyze its dependence on both the number of SFPs contributing either to the triggering peak or the non-triggered peak, and time shifting (delays of triggering at the end-plate) of individual SFPs in these paired potentials. MethodsWe simulated potentials recorded using a concentric needle electrode with two well separated peaks, and performed a simulated examination (consisting of 50 trains of 100 discharges) with an assumed number of fibers forming peaks. For each train, fiber diameters were chosen at random within the allowed ranges. For each discharge the delay of triggering for each fiber at the end-plate was selected at random from an assumed range. The mean jitter values were calculated, together with the median and 95% quantile. ResultsThe results suggest that jitter is related to the mean of the individual SFP shifts. ConclusionThese findings extend the understanding of reduced jitter measurements using a concentric needle electrode. If more than one fiber forms the peak, then jitter decreases due to averaging of individual time shifts of potentials constituting the peak, rather than due to detection of the SFP with the earliest peak.

Assessment of Voice Changes in Myasthenia Gravis Patients

Objective: This study aims to examine the changes between the measurements done in the morning and evening in some acoustic analyses of patients having myasthenia gravis (MG). Materials and Methods: Twenty-four MG patients diagnosed with Phase-2A (Mildly Generalized MG) according to the classification of Osserman and Genkins by a neurology specialist were involved. Videolaryngostroboscopic examinations and acoustic analyses of these patients were performed in the Ear, Nose, and Throat (ENT) clinic. Perceptual voice assessments were performed using the GRBASI scale, Fo, Shimmer, Jitter, NHR (Noise to harmonic ratio), MPT (Maximum Phonation Time), and s/z rates were calculated. Results: When the morning and evening vocal measurements of patients were compared according to the GRBASI scale, a significant difference was found between B and A and S values, while no statistically significant difference was found between G, R, and I value. Statistically significant differences were found between cases’ Fo, Shimmer, NHR, s/z Ratio, and VHI (voice handicap index) measurements made in the morning and the evening. But no difference was found between the Jitter measurements. A statistically significant difference was found between the morning and evening values of men’s Fo and MPT measurements. Again, a statistically significant difference was found between the morning and evening values of women’s Fo and MPT measurements. Conclusion: For Myasthenia Gravis patients, the decrease in muscle power within the day and the tiredness in larynx muscles are an expected process, and it is objectively presented in this study. In addition, further studies are needed to show that possible communication problems can be prevented with sound therapies by evaluating the morning and evening acoustic analyses of MG patients.

A Comparison of Healthy and Disordered Voices Using Multi-Dimensional Voice Program, Praat, and TF32

Instrumental voice assessment plays a critical role in identifying vocal issues and for documenting treatment outcomes. The reported voice data, however, are sensitive to the algorithm used by each acoustic analysis software program (AASP) to analyze the corresponding waveform. In the present study, five acoustic measures were compared across healthy speakers and speakers with dysphonia for three AASPs commonly used in research, education, and clinical practice: Multidimensional Voice Program (MDVP) by Computerized Speech Lab, Praat, and TF32. Sustained vowel phonations for the quantal vowels /ɑ/, /i/, and /u/ were analyzed for 80 speakers with organic dysphonia and 60 age- and sex-matched healthy controls. Descriptive, inferential, and correlation data are reported for mean fundamental frequency (mean F0), standard deviation of fundamental frequency (SD F0), short-term perturbation measures of jitter and shimmer, and harmonic-to-noise ratio (HNR). The present study replicated previous findings of interprogram differences for healthy speakers, with MDVP consistently yielding higher values than Praat and TF32 for SD F0, jitter, and shimmer and lower values for HNR. Similar, but magnified patterns of results were observed for speakers with dysphonia. The variation observed across programs calls into question the validity in comparing voice outcomes reported by one AASP to those previously obtained by another, particularly for acoustic signals with aperiodic components that are commonly present in disordered voices. It is advised that waveforms be visually inspected prior to conducting acoustic analysis, and that voice outcomes not be combined or compared across AASPs.

High-power low-noise 2-GHz femtosecond laser oscillator at 2.4 µm.

Femtosecond lasers with high repetition rates are attractive for spectroscopic applications with high sampling rates, high power per comb line, and resolvable lines. However, at long wavelengths beyond 2 µm, current laser sources are either limited to low output power or repetition rates below 1 GHz. Here we present an ultrafast laser oscillator operating with high output power at multi-GHz repetition rate. The laser produces transform-limited 155-fs pulses at a repetition rate of 2 GHz, and an average power of 0.8 W, reaching up to 0.7 mW per comb line at the center wavelength of 2.38 µm. We have achieved this milestone via a Cr2+-doped ZnS solid-state laser modelocked with an InGaSb/GaSb SESAM. The laser is stable over several hours of operation. The integrated relative intensity noise is 0.15% rms for [10 Hz, 100 MHz], and the laser becomes shot noise limited (-160 dBc/Hz) at frequencies above 10 MHz. Our timing jitter measurements reveal contributions from pump laser noise and relaxation oscillations, with a timing jitter of 100 fs integrated over [3 kHz, 100 MHz]. These results open up a path towards fast and sensitive spectroscopy directly above 2 µm.

The Jitter Measurement Ways: The Instrumentation

Jitter characterization is an essential requirement for different applications and technologies. For this reason, measurement approaches, decomposition methods and measurement instruments aimed at quantifying and analyzing jitter continue to be object of great interest both for researchers and manufacturers. Currently, various instruments are available to measure jitter, each one having specific advantages and disadvantages. To help engineers who deal with jitter measurements, this paper provides a schematic overview of the main types of instruments available on the market.

Quality of Service (QoS) for Network Performance Analysis Wireless Area Network (WLAN)

Quality of Service (QoS) is the ability of a network to provide good service by providing bandwidth, overcoming jitter and delay. Wireless LAN network performance must always be maintained properly. Therefore, to determine the quality of the wireless LAN internet network at Asahan University, it is necessary to analyze network performance, focus on how to monitor and measure the performance of the wireless LAN network, and find out how big the network performance is on the infrastructure. as the speed of access from the sending point to the destination point. Access speed is measured by measuring throughput, delay, jitter and packet loss on the network at Asahan University. Research conducted using quantitative methods consists of 4 stages, namely conceptual, design, empirical and analytical. In the QoS (Quality of Service) analysis carried out using the Wireshark application and using the TIPHON standard, the results obtained from the quality of the WLAN network of each faculty at Asahan University are different. Throughput measurement obtained an average result of 582.08 Kb/s and is categorized as medium. The average packet loss measurement result is 5.39% and is categorized as good. The delay measurement results obtained an average of 15.62 ms and is categorized as very good. The average result of the jitter measurement is 4.50ms with good category.