Amplitude Stability Research Articles

Quantifying local field potential dynamics with amplitude and frequency stability between ON and OFF medication and stimulation in Parkinson's disease

Neural oscillations are critical to understanding the synchronisation of neural activities and their relevance to neurological disorders. For instance, the amplitude of beta oscillations in the subthalamic nucleus has gained extensive attention, as it has been found to correlate with medication status and the therapeutic effects of continuous deep brain stimulation in people with Parkinson's disease. However, the frequency stability of subthalamic nucleus beta oscillations, which has been suggested to be associated with dopaminergic information in brain states, has not been well explored. Moreover, the administration of medicine can have inverse effects on changes in frequency and amplitude. In this study, we proposed a method based on the stationary wavelet transform to quantify the amplitude and frequency stability of subthalamic nucleus beta oscillations and evaluated the method using simulation and real data for Parkinson's disease patients. The results suggest that the amplitude and frequency stability quantification has enhanced sensitivity in distinguishing pathological conditions in Parkinson's disease patients. Our quantification shows the benefit of combining frequency stability information with amplitude and provides a new potential feedback signal for adaptive deep brain stimulation.

A Method for Stabilizing the Vibration Amplitude of a Flip-Flow Vibrating Screen Using Piecewise Linear Springs

The flip-flow vibrating screen (FFVS) is a novel multi-body screening equipment that utilizes vibrations to classify bulk materials in the field of screening machinery. The relative amplitude of FFVSs determines the tension and ejection intensity of elastic flip-flow screen panels, which is a critical operating parameter affecting the screening performance. However, FFVSs generally suffer from large variations of relative amplitude caused by the loading of materials and the changes in shear spring stiffness (the temperature changes of the shear springs lead to their stiffness changes), which significantly reduce the screening efficiency and lifespan of FFVSs. To address this problem, this paper proposes a nonlinear stiffness-based method for stabilizing the vibration amplitude of FFVSs using piecewise linear springs. By introducing these springs between the two frames, the sensitivity of the relative amplitude to shear spring stiffness is reduced, thereby achieving the stabilization of the relative amplitude of FFVSs. In this study, the variations of the vibration amplitude of the FFVS due to the loading of materials and the changes in shear spring stiffness were first demonstrated in a reasonable operating frequency range. Then the reasonable operating frequency range and dynamics of the resultant nonlinear flip-flow vibrating screen (NFFVS) with piecewise linear springs were investigated using the harmonic balance method (HBM) and the Runge–Kutta numerical method. The operating frequency region for the NFFVS lies between the critical frequency ωcs and the frequency ωlb corresponding to the saddle-node bifurcation point. Finally, a test rig was designed to validate the theoretical predictions. Theoretical and experimental results demonstrate that piecewise linear springs can effectively stabilize the relative amplitude of the FFVS.

Acute to long-term characteristics of impedance recordings during neurostimulation in humans

Objective. This study aims to characterize the time course of impedance, a crucial electrophysiological property of brain tissue, in the human thalamus (THL), amygdala-hippocampus, and posterior hippocampus over an extended period. Approach. Impedance was periodically sampled every 5–15 min over several months in five subjects with drug-resistant epilepsy using an investigational neuromodulation device. Initially, we employed descriptive piecewise and continuous mathematical models to characterize the impedance response for approximately three weeks post-electrode implantation. We then explored the temporal dynamics of impedance during periods when electrical stimulation was temporarily halted, observing a monotonic increase (rebound) in impedance before it stabilized at a higher value. Lastly, we assessed the stability of amplitude and phase over the 24 h impedance cycle throughout the multi-month recording. Main results. Immediately post-implantation, the impedance decreased, reaching a minimum value in all brain regions within approximately two days, and then increased monotonically over about 14 d to a stable value. The models accounted for the variance in short-term impedance changes. Notably, the minimum impedance of the THL in the most epileptogenic hemisphere was significantly lower than in other regions. During the gaps in electrical stimulation, the impedance rebound decreased over time and stabilized around 200 days post-implant, likely indicative of the foreign body response and fibrous tissue encapsulation around the electrodes. The amplitude and phase of the 24 h impedance oscillation remained stable throughout the multi-month recording, with circadian variation in impedance dominating the long-term measures. Significance. Our findings illustrate the complex temporal dynamics of impedance in implanted electrodes and the impact of electrical stimulation. We discuss these dynamics in the context of the known biological foreign body response of the brain to implanted electrodes. The data suggest that the temporal dynamics of impedance are dependent on the anatomical location and tissue epileptogenicity. These insights may offer additional guidance for the delivery of therapeutic stimulation at various time points post-implantation for neuromodulation therapy.

The Influence of Amplitude Stability Index Values in Mapping Land Movements on Sipora Island

Sipora Island in the Mentawai Islands Regency is prone to land movement disasters that can damage and cause losses to the people who live on Sipora Island, plus very little data base related to land movement maps on the island. To reduce the risk that will arise, it is necessary to map land movement using the PS-InSAR method, using 48 scenes of Sentinel-1A images and comparing the amplitude stability index parameters 0.65, 0.75, and 0.85 to get differences in the distribution of land movement points and the number of land movement points on the island of Sipora, to see the relationship between the value of the amplitude of the stability index is done fisher test, amplitude stability index parameters 0.65 and 0.75 can map points with subsidence value up to -99mm / year while the amplitude stability index parameter 0.85 can map points with subsidence value -87mm / year all parameters have a maximum uplift value of 5mm / year. The number of points obtained with an amplitude stability index of 0.65 is 27561, 0.75 is 961 and 0.85 is 255. The distribution of land movement points parameter value amplitude stability index 0.65 covers the entire surface of the island of Sipora, the distribution of land movement points amplitude stability index 0.75 focuses on the north and south of the island and the distribution of land movement points amplitude stability index 0.85 in the northern part of the island. The difference parameters of amplitude stability index 0.65, 0.75 and 0.85.

Self-Powered Intelligent Water Droplet Monitoring Sensor Based on Solid-Liquid Triboelectric Nanogenerator.

Real-time monitoring of rainwater is a critical issue in the development of autonomous vehicles and smart homes, while the corresponding sensors play a pivotal role in ensuring their sensitivity. Here, we study a self-powered intelligent water droplet monitoring sensor based on a solid-liquid triboelectric nanogenerator (SL-TENG). The sensor comprises a SL-TENG, a signal acquisition module, a central processing unit (CPU), and a wireless transmission module, facilitating the real-time monitoring of water droplet signals. It is worth noting that the SL-TENG has self-powering characteristics and can convert the kinetic energy of water droplets into electrical energy. The excellent output performance, with open-circuit voltage of 9 V and short-circuit current of 2 μA without any treatment of the SL-TENG, can provide an effective solution to the problem that traditional sensor need battery replacement. In addition, the SL-TENG can generate stable amplitude electrical signals through water droplets, exemplified by the absence of decay in a short-circuit current within 7 days. More importantly, the sensor is equipped with intelligent analytical capabilities, allowing it to assess rainfall based on variables such as amplitude and frequency. Due to its excellent stability and intelligent analysis, this sensor can be used for roof rainwater monitoring, intravenous administration monitoring, and especially in automobile automatic wipers and other fields.

Quantum dot laser dynamics and external filtered modes under the influence of double-filtered optical feedback

We study the dynamics and solution structure of a semiconductor quantum dot (QD) laser system that gets delayed FOF from two filter loops: the double-filtered optical feedback (DFOF) laser. Two filters are utilized in optical communication applications to regulate and stabilize the laser output, which served as the inspiration for this study. The entire mathematical model of the DFOF laser consists of delay differential equations for the inversion of the QD laser with the two filters. We focus on continuous-wave DFOF QD laser systems because reliable laser source operation is essential for optical communication applications. These basic responses are called external filtered modes (EFMs), and they significantly affect the stability and structure of the EFMs as well as the laser’s performance in comparison to the single FOF QD laser. The parameter C eff is a measure of the interference between the two filter fields, and it is identified as a key to the EFM structure. To analyse how the structure and stability of the EFMs depend on all the filter and feedback loop parameters, we make extensive use of the EFM surface in the (Ω(ω s), C eff , Y s )-space of frequency s, filter phase difference C eff , and population inversion Y s of the QD laser. In general, the EFM surface is the natural object that should be taken into account to comprehend the dynamical characteristics of the DFOF laser. In general, our study involved searching for regions in the QD laser output with stable amplitude and frequency. The time delay suppression is dependent on the spectral width Λ of the filter and how far it is from the solitary laser frequency, according to numerical calculations. In addition to studying the dynamic behavior using a bifurcation diagram at the filter working areas, the results showed two stages of operation due to the occurrence of phase entanglement stochastic.

Control of Vibratory Feeder Device Mechanical Frequency Using the Modification of the Sinusoidal Supply Voltage Signal

In the industrial and sales processes, dosing systems of various constructions, whose operation is based on mechanical vibrations (vibratory feeders), are very often used. These systems face many problems, such as resonant frequency, flow instability of dosed product, instability of mechanical vibration amplitude, etc., because most of them are based on controlling the frequency of the electrical signal of the supply voltage. All these factors negatively affect the durability and reliability of the vibratory feeder systems. During this research, an automatic control system for vibratory feeder was created, whose control process is based on the modification of the sinusoidal signal (partially changing the signal area). In addition, such a way of controlling the vibratory feeder is not discussed in the literature. As the research conducted in this paper has shown, while using sinusoidal signal modification it was possible to achieve a stable flow rate of bulk production (the flow rate varied from 0 to 100 g/s when the frequency of mechanical vibrations changed from 1 to 50 Hz) and a stable amplitude of mechanical oscillations was achieved and equal to 1.5 mm. The control system is based on the microcontroller PIC24FV32KA302 for which the special software was developed. The thyristor BTA16 used for voltage modification of the sinusoidal signal made it possible to ensure the reliable control of the sinusoidal voltage modification process.

Quantum cascade lasers as broadband sources via strong RF modulation

In this work, we demonstrate that in a regime of strong modulation, by generating pulses of the length of the order of a few cavity lifetimes (hundreds of ps), a broadband quantum cascade laser can be driven to lase on a bandwidth (250 cm−1) limited by the gain. In addition, the amplitude noise of the radiation was shown to be limited by the detector. A laser linewidth study has been performed under different operating conditions, finding values spanning from 20 to 800 MHz, indicating a trade-off between emission bandwidth, amplitude stability, and coherence. The pulsed intensity of the output arises from the gain switching dynamics of the laser, while the self-seeded nature of the emission is responsible for the low amplitude noise and the relatively narrow linewidth of the individual spectral lines of the multimode emission.

Vector-based feedback of continuous wave radiofrequency compression cavity for ultrafast electron diffraction.

The temporal resolution of ultrafast electron diffraction at weakly relativistic beam energies (100 keV) suffers from space-charge induced electron pulse broadening. We describe the implementation of a radio frequency (RF) cavity operating in the continuous wave regime to compress high repetition rate electron bunches from a 40.4 kV DC photoinjector for ultrafast electron diffraction applications. Active stabilization of the RF amplitude and phase through a feedback loop based on the demodulated in-phase and quadrature components of the RF signal is demonstrated. This scheme yields 144 ± 19 fs RMS temporal resolution in pump-probe studies.

Quasi-Periodic Traveling Waves on an Infinitely Deep Perfect Fluid Under Gravity

We consider the gravity water waves system with a periodic one-dimensional interface in infinite depth and we establish the existence and the linear stability of small amplitude, quasi-periodic in time, traveling waves. This provides the first existence result of quasi-periodic water waves solutions bifurcating from a completely resonant elliptic fixed point. The proof is based on a Nash–Moser scheme, Birkhoff normal form methods and pseudo differential calculus techniques. We deal with the combined problems of small divisors and the fully-nonlinear nature of the equations. The lack of parameters, like the capillarity or the depth of the ocean, demands a refined nonlinear bifurcation analysis involving several nontrivial resonant wave interactions, as the well-known “Benjamin-Feir resonances”. We develop a novel normal form approach to deal with that. Moreover, by making full use of the Hamiltonian structure, we are able to provide the existence of a wide class of solutions which are free from restrictions of parity in the time and space variables.

Towards liquid EPR dosimetry using nitroxides in aqueous solution.

Objective. Water-equivalent dosimeters are desirable for dosimetry in radiotherapy. The present work investigates basic characteristics of novel aqueous detector materials and presents a signal loss approach for electron paramagnetic resonance (EPR) dosimetry.Approach. The proposed principle is based on the radiation dose dependent annihilation of EPR active nitroxides (NO·) in aqueous solutions. Stable nitroxide radicals (3-Maleimido-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (MmP), 3-Carbamoyl-2,2,5,5-tetramethyl-1-pyrrolidinyloxy (CmP)) in aqueous solutions containing dimethyl sulfoxide (DMSO) as an additive were filled in glass capillaries for irradiation and EPR readout. Radiation doses ranging from 1 to 64 Gy were applied with a clinical 6 MV flattening filter free photon beam. EPR readout was then performed with a X-band benchtop spectrometer. The dose response, temporal stability and reproducibility of the samples' EPR signal amplitudes as well as the influence of the nitroxide concentration between 10 and 160μM on the absolute signal loss were investigated using MmP. CmP was used to examine the dependence of the dose response on DMSO concentration between 0 and 10 vol%. An indirect effect model was fitted to the experimental data assuming irradiation induced radical reactions as the underlying mechanism.Main results. For an initial MmP concentration of 20μM, absolute EPR signal loss is linear up to a dose of 16 Gy with a yield G(-NO·) of approximately 0.4μmol J-1. Within five weeks upon sample irradiation to doses between 0 and 32 Gy relative EPR signal fluctuations were on average (126 readouts) below 1% (1σ). For c(MmP) ≥ 20μM, absolute signal loss is only weakly dependent on c(MmP), whereas it increases strongly with increasing c(DMSO) in the range 0-5 vol%. An indirect effect model is applicable to describe the reaction mechanism resulting in the observed dose response curve.Significance. Liquids consisting of nitroxides in aqueous solution and small amounts of DMSO (2 vol%) show promising basic characteristics for application as water-equivalent EPR dosimeter materials in radiotherapy. The EPR signal loss is based on an indirect effect mediated by diffusing radicals originating from the radiolysis of the water/DMSO mixture.

A digital prediction compensation for DR improvement in CT DSM with digital noise coupling

AbstractThis paper presents a prediction‐based dynamic range (DR) compensation technique in continuous‐time (CT) delta ‐sigma modulator (DSM) with digital‐domain noise coupling (DNC) structure. A digital prediction technique is proposed to address the issue of maximum stable amplitude (MSA) loss caused by DNC. The proposed prediction method has been shown to significantly extend the MSA of CT DSM with DNC. Moreover, through the extension of MSA, the DR and SNDR is significantly improved. A CTDSM with proposed compensation achieves a SNDR of 85.1dB at ‐1dBFS and a DR of 89dB.

Weakly nonlinear analysis of a two-species non-local advection–diffusion system

Nonlocal interactions are ubiquitous in nature and play a central role in many biological systems. In this paper, we perform a bifurcation analysis of a widely-applicable advection–diffusion model with nonlocal advection terms describing the species movements generated by inter-species interactions. We use linear analysis to assess the stability of the constant steady state, then weakly nonlinear analysis to recover the shape and stability of non-homogeneous solutions. Since the system arises from a conservation law, the resulting amplitude equations consist of a Ginzburg–Landau equation coupled with an equation for the zero mode. In particular, this means that supercritical branches from the Ginzburg–Landau equation need not be stable. Indeed, we find that, depending on the parameters, bifurcations can be subcritical (always unstable), stable supercritical, or unstable supercritical. We show numerically that, when small amplitude patterns are unstable, the system exhibits large amplitude patterns and hysteresis, even in supercritical regimes. Finally, we construct bifurcation diagrams by combining our analysis with a previous study of the minimizers of the associated energy functional. Through this approach we reveal parameter regions in which stable small amplitude patterns coexist with strongly modulated solutions.

Installation and test procedure for frequency stability under cyclic loading of metals and alloys

Manufacture of parts operating under difficult conditions of cyclic loading, as well as products with stable dimensions necessitates the use of materials with minimal manifestations of inelastic properties. Study of these materials suggests conducting specialized narrowly focused tests using newly developed machines and installations with appropriate experimental techniques. We present the design, operation and control features of the original electromagnetic installation for testing fatigue and frequency stability and operating in a self- oscillating mode, which provides the equality of the frequency of cyclic loading and natural frequency of the sample. The system of the installation control contains two closed circuits: for excitation of self-oscillations and for stabilization of the oscillation amplitude. The sample is loaded by electromagnetic force, and unloading occurs due to the elastic forces of the material. The methodology and algorithms for calculating the stresses of samples of various geometric shapes for estimating changes in amplitude-frequency characteristics are presented. The calculated relationship between the force applied to the sample and its movement at the point of application of force is derived with subsequent determination of the stress by a known force. The results of calibration tests for the static mode of sample loading are presented and the forces acting on the sample (external, inertia, and elastic forces) are evaluated taking into account the maximum stress and maximum strain amplitude. Static and cyclic loading modes are compared. The frequency characteristics obtained during testing steel samples according to the proposed method are obtained. The experimental results of tests with interruptions in the process of cyclic loading and continuous testing are analyzed. It is shown that interruptions in cyclic tests lead to a jump-like increase in the frequency, whereas continuous tests revealed no jumps. At the same time, a comparative analysis with the results of continuous tests showed that the overall frequency deviation is approximately the same for the entire operating cycle in both cases. It is shown that an increase in the frequency after rest is random and does not depend on the number of operating cycles.

Development of a digital low-level RF system for the STCF

With the development of particle physics, higher requirements are put forward for the brightness and energy of the collider. A new collider — the Super Tau-Charm Facility (STCF) — is under study in China. To meet the high acquirement of the quality of the beam, a digital low-level RF (LLRF) system that achieves high stability plays a critical role as a part of the microwave system of Linacs. This paper introduces the design of a digital LLRF system that works in the S-band (2856 MHz) as required by Linacs of the STCF. The system architecture and hardware design as well as the control algorithms and software design are discussed and tested. The system includes a signal source, a frequency synthesis system and an IF signal processor. The phase noise of the signal source is as low as 20.3 fs, and the low-level IF signal processor adopts amplitude and phase control by a PI-type controller. They jointly realize ultra-low phase noise signal output. The table experiments show that the short-term amplitude and phase stability of the system is better than 0.01% and 0.01°, respectively. The beam experiments show that the closed-loop phase stability in the cavity is about 0.1°. The results prove that the LLRF system meets the requirement of the STCF.

Reducing motor evoked potential amplitude variability through normalization.

BackgroundTranscranial Magnetic Stimulation (TMS) is used for in vivo assessment of human motor cortical excitability, with application of TMS pulses over the motor cortex resulting in muscle responses that can be recorded with electromyography (EMG) as Motor Evoked Potentials (MEPs). These have been widely explored as potential biomarkers for neuropsychiatric disorders but methodological heterogeneity in acquisition, and inherent high variability, have led to constraints in reproducibility. Normalization, consisting in scaling the signal of interest to a known and repeatable measurement, reduces variability and is standard practice for between-subject comparisons of EMG. The effect of normalization on variability of MEP amplitude has not yet been explored and was assessed here using several methods.MethodsThree maximal voluntary isometric contractions (MVICs) and 40 MEPs were collected from the right hand in healthy volunteers, with a retest session conducted 4 to 8 weeks later. MEP amplitude was normalized using either external references (MVICs) or internal references (extreme MEPs). Iterative re-sampling of 30 normalized MEPs per subject was repeated 5,000 times to define, for each normalization method, distributions for between-subject coefficients of variation (CV) of the mean MEP amplitude. Intra-class correlation coefficients (ICC) were used to assess the impact of normalization on test–retest stability of MEP amplitude measurements.ResultsIn the absence of normalization, MEPs collected from the right hand of 47 healthy volunteers were within reported values regarding between-subject variability (95% confidence intervals for the CV: [1.0567,1.0577]) and showed good temporal stability (ICC = 0.77). Internal reference normalization substantially reduced between-subject variability, by values of up to 64%, while external reference normalization had no impact or increased between-subject variability. Normalization with the smallest references reduced test–retest stability, with use of the largest references resulting in slight reduction or improvement of ICCs. Internal reference normalization using the largest MEPs was found to be robust to several sensitivity analyses.ConclusionInternal, but not external, reference normalization reduces between-subject variability of MEP amplitude, and has a minimal impact on within-subject variability when conducted with the largest references. Additional research is necessary to further validate these normalization methods toward potential use of MEPs as biomarkers of neuropsychiatric disorders.

Bayesian deep neural network for low-carbon scheduling strategy planning of V2G

Abstract With the increasing adoption of electric vehicles, the Vehicle-to-Grid (V2G) model has become crucial in integrating renewable energy generation. However, challenges exist in developing grid scheduling strategies that are tailored to different regions, as well as in quantifying the economic benefits and carbon emissions associated with such scheduling. To address these issues, our study proposed a novel V2G low-carbon scheduling strategy planning method based on Bayesian neural networks. Initially, we established a stochastic V2G model that incorporated grid and electric vehicle scheduling, along with a mathematical model that captured the random behavior of EV users, enabling us to capture the essential characteristics of scheduling planning. Subsequently, we employed an enhanced Bayesian deep neural network to learn and assimilate these scheduling planning characteristics, allowing for the provision of a grid scheduling strategy that ranks economic benefits based on weighted priorities. Furthermore, we conducted simulation experiments within the coverage area of the Internet of Things in Energy (IoTE) to gather scheduling characteristics. The experimental results demonstrated that our method outperformed other deep learning models in terms of voltage amplitude stability during the grid scheduling process, showcasing superior robustness and accuracy. Moreover, we evaluated the economic benefits of the scheduling model and compared it with the original V2G scheduling model. The findings revealed that our model exhibited higher economic benefits and lower carbon emissions. Considering the future challenges of low-carbon urban planning, our method holds significant potential in terms of grid scheduling economic benefits and carbon emission indicators.

A novel robustness matching method based on amplitude-frequency characteristic for high power ultrasonic system under variable load

In order to solve the insufficiency of the driving capacity when the load of the ultrasonic driver changes, a high robustness LC matching design method is proposed based on the equivalent circuit modeling and the amplitude-frequency characteristic analysis of circuit transfer function. The transfer function of the input current including the matching capacitance and inductance is established by using the amplitude-frequency characteristics of the circuit transfer function. In order to simplify the transfer function, two new parameters as: impedance coefficient kz and frequency coefficient kf is introduced and a robust matching method based on uncertainty solving is proposed. The superiority of the proposed method compared with the existing matching method is proved by simulation and experiment. The experimental results show that the current fluctuation is less than 10% from light load to full load, which proves the reliability and robustness of our proposed method is higher than the existing matching method. It can ensure the amplitude stability of the ultrasonic transducer, and its performance is optimal than the existing general matching method.

Study on dynamic characteristics of scraper conveyor under various scraper configurations

This study aims to explore the impact of scraper structure on the stable operation of scraper conveyors. A simulation test is designed to investigate the effect of the scraper's lower inclination angle on the wedge-shaped structure of the scraper. Based on the test results, modifications are made to the scraper's lower inclination angle. Using the DEM-MBD coupling model of the scraper conveyor, simulation analyses are conducted to evaluate the influence of the scraper on the dynamic characteristics of the conveyor before and after the modification. The simulation test results reveal that, when coal materials are stuck, the minimum impact force of coal material on the upper sample is observed at inclination angles of 52.35° and 78.19°. The simulation research indicates that the transportation efficiency of the standard scraper and the single-sided 52.35° and 78.19° modified scraper is similar. The single-sided 78.19° scraper demonstrates the most stable vibration amplitude and centroid variance, with an overall maximum vibration amplitude and variance of 0.76 mm and 0.08, respectively. The z-direction speed fluctuation of the single-sided 78.19° scraper is also the smallest and most stable, with a maximum peak-valley difference and fluctuation variance of 0.17 m/s and 0.0004, respectively. Additionally, the force of the coal on the single-sided 78.19° scraper is the smallest and relatively stable, with a fluctuation range of 510.28∼ 18,557.71 N. Overall, the dynamic operation effect of the single-sided 78.19° scraper is deemed the best after considering all factors. This study provides valuable insights into the influence of scraper structure with different lower inclination angles on the stable operation of scraper conveyors and offers a reference for optimizing scraper structure.

Low-Level Radio-Frequency system integrated with feed-forward control and vector modulation

To provide a more accurate and stable Radio-Frequency (RF) signal in conditioning and processing test progress, it is necessary to design a Low-Level Radio-Frequency (LLRF) control system which can provide high precision RF driving signal based on meeting the amplitude and phase stabilization requirement. Through Feed-Forward operation, accurate phase adjustment and amplitude adjustment are realized inside the pulse, to realize the precision and automation of phase-inversion, amplitude stabilization, phase stabilization, and wave-form adaptation matching. An LLRF System integrated with feed-forward control and vector modulation output was designed and built, and the long-term working stability of the LLRF system was verified during a new 50MW S-band Klystron conditioning progress.