Output Frequency Research Articles

High-sensitivity blue-energy-shuttle and in-situ electrical behaviors in ocean

Although various triboelectric nanogenerators (TENGs) and hybrid ocean kinetic energy harvesters (OKEHs) have been devised for blue energy harvesting, the lack of studies in the real ocean has hindered their progress. Here, a high-sensitivity modular shuttle-like hybrid nanogenerator (MSHG) is prepared, comprising contact-separation TENG, piezoelectric nanogenerator (PENG), and electromagnetic generator (EMG) components. Its acceleration feature and electrical performance were systematically investigated under various conditions, from laboratory setups to real ocean waves. The MSHG responds sensitively to low-level excitations and exhibits robust energy harvesting capability in the ocean. Statistical analysis shows that its most probable output frequency reaches 0.83 Hz, which is about four times higher than the main frequency of the ocean wave (0.1–0.2 Hz). A 12-integrated MSHG system effectively harvests ocean wave energy to power a water-quality detector, while its most probable acceleration amplitude is approximately 24% of the maximum in a simulated linear motor motion and 57% of the mean value under simulated water wave. The findings provide valuable insights for advancing nanogenerator applications in real oceans.

A resonant high-pressure microsensor based on a composite pressure-sensitive mechanism of diaphragm bending and volume compression

In this paper, a composite pressure-sensitive mechanism combining diaphragm bending and volume compression was developed for resonant pressure microsensors to achieve high-pressure measurements with excellent accuracy. The composite mechanism was explained, and the sensor structure was designed based on theoretical analysis and finite element simulation. An all-silicon resonant high-pressure microsensor with multiple miniaturized cavities and dual resonators was developed, where dual resonators positioned in two resonant cavities with suitably different widths are used to perform opposite characteristics in pressure and the same characteristics at different temperatures, which can improve pressure sensitivities and realize temperature self-compensation by differential frequency output. The microsensor was fabricated by microfabrication, and the experimental results showed that the sensor had an accuracy of ±0.015% full scale (FS) in a pressure range of 0.1~100 MPa and a temperature range of −10~50 °C. The pressure sensitivity of the differential frequency was 261.10 Hz/MPa (~2523 ppm/MPa) at a temperature of 20 °C, and the temperature sensitivities of the dual resonators were −1.54 Hz/°C (~−14.5 ppm/°C) and −1.57 Hz/°C (~−15.6 ppm/°C) at a pressure of 2 MPa. The differential output had an outstanding stability within ±0.02 Hz under constant temperature and pressure. Thus, this research provides a convenient solution for high-pressure measurements because of its advantages, namely, large range, excellent accuracy and stability.

Consensus-based secondary frequency control for parallel virtual synchronous generators

In off-grid operating modes, microgrids with Virtual Synchronous Generators (VSG) controlled inverters are limited to primary frequency control capabilities. When operating under the primary frequency control, if VSG's output frequency exceeds the safe operational range, it can adversely affect stable operation. Consequently, there is a need to implement a secondary frequency control strategy. This paper presents an analysis of the conventional secondary frequency regulation in VSGs. It reveals that when multiple VSGs in parallel to the Point of Common Coupling (PCC) with varied line impedances, the proportionate distribution of each VSG's active power output, post frequency control, does not align with predetermined ratios. In response to this challenge, the paper introduces a quasi-distributed secondary frequency control approach, tailored for systems with multiple feed-in points. This approach modifies the traditional method of compensating for frequency deviation through average ratio integral compensation, replacing it with a compensation based on a consensus algorithm. This negates the need for global communication and additional impedance measuring equipment. By facilitating information exchange between neighboring converters, it enables global control, effectively resolving the issue of line impedance parameters impacting the distribution of VSG's active power output. This decouples the previously strong correlation between line impedance and VSG's active power. The proposed method is characterized by its strong adaptability, scalability, and swift dynamic adjustments, significantly enhancing the fault tolerance of information exchange and the stability of microgrid operations. Finally, the correctness and effectiveness of the proposed improved control strategy are verified by simulation and HIL-based platform.

Application of nonlinear system identification and feature extraction in fault diagnosis of the cracked cantilever beam

The cantilever beam structure is extensively applied in civil, transportation, and mechanical fields. It is generally prone to structural damage like cracks arising from material defects, operation conditions, and environmental factors. Cracks in a cantilever beam generally induce nonlinear behavior, potentially compromising structural durability and even posing threats to production safety. The present study primarily focuses on online and quantitative fault diagnosis of cracks in the cantilever beam. A simulation model is established for the cantilever beam with varying cracks, where responses corresponding to excitation signals are collected. A Nonlinear Autoregressive with Exogenous inputs (NARX) model for the cantilever beam is identified, and Nonlinear Output Frequency Response Functions weighted contribution rate (WNOFRFs) are evaluated from the established NARX model. A WNOFRFs-associated index is extracted to quantify the severity of breathing cracks. Simulation results indicate that this approach can online diagnose and quantify the severity of crack faults to a certain extent. The applicability of this approach is further verified through experiments on a cracked cantilever beam.

Smartphone-Facilitated In-Situ Hearing Aid Audiometry for Community-Based Hearing Testing.

Hearing loss prevalence is increasing, with an estimated 2.5 billion people affected globally by 2050. Scalable service delivery models using innovative technologies and task-shifting are World Health Organization priorities to improve access to hearing care, particularly in low- and middle-income countries. Smartphone-facilitated audiometry in the community using hearing aids covered by noise-attenuating ear cups ("in-situ") could support more accessible hearing care when provided by less trained individuals such as community health workers (CHWs). This study aimed to determine the validity of this method for potential hearing aid fitting. Study objectives included determining the maximum permissible ambient noise level (MPANL), inter-device reliability, clinical threshold accuracy, reliability, and performance in real-world settings. Experiment 1: 15 normal-hearing adult participants were evaluated to determine MPANLs for circumaural Peltor 3M earcups covering Lexie Lumen hearing aids with smartphone-facilitated in-situ audiometry. MPANLs were calculated by measuring the difference in attenuation between thresholds obtained with standard headphones and in-situ hearing aids. Experiment 2: Pure-tone frequency and intensity output of 14 same-model Lexie Lumen hearing aids were measured to determine inter-device reliability. Pure-tone stimuli were measured and analyzed to determine sound pressure levels in decibels and pure-tone frequency when connected to a test box 2cc coupler. Experiment 3: 85 adult participants were tested in a sound booth to determine the accuracy of automated in-situ pure-tone audiometry (PTA) compared to clinical PTA (500, 1000, 2000, 3000, 4000, 6000 Hz) facilitated by an audiologist. The first 39 participants were tested twice to determine test-retest reliability. Experiment 4: In a community setting, 144 adult participants were tested with automated in-situ audiometry facilitated by CHWs using a smartphone app. These participants were subsequently tested with automated mobile PTA (500, 1000, 2000, 4000 Hz). An additional 44 participants were tested twice to determine test-retest reliability. Experiment 1: MPANLs of the Peltor 3M earcup-covered hearing aids were higher than standard headphones across all frequencies, ranging from 24 to 47.3 dB SPL. Experiment 2: Inter-device performance reliability was high, with all inter-device differences across all intensities and frequencies less than 3 dB. Frequency output was consistent and differed less than 0.7% between devices. Experiments 3 and 4: 85.2% and 83.3% of automated in-situ audiometry thresholds were within 10 dB of thresholds obtained in the sound booth and in a community setting, respectively. Acceptable test-retest intraclass correlation coefficient (ICC) was evident across all thresholds obtained in a sound booth (ICC = 0.85 to 0.93) and in a community setting (ICC = 0.83 to 0.97). Smartphone-facilitated in-situ audiometry allows for reliable and valid community-based testing. A simple smartphone user interface and automated in-situ audiometry allow CHWs with minimal training to facilitate the testing. With the additional capability to program hearing aids via the smartphone after the initial test, this approach would have the potential to support widespread access to personalized hearing aid fittings facilitated by CHWs in low- and middle-income countries. This approach also supports self-fitting options based on in-situ thresholds, enabling testing and fitting via over the counter hearing aids.

A new X‐band frequency up‐converter design for LEO satellite ground station utilizing a single superheterodyne

AbstractIn this work, the advancing wireless revolution (AWR) modeling and Microwave Office tools are used to develop and execute a broadband up‐converter system. Before sending the input frequency to the antenna interface, a radio frequency block upconverts it once to the appropriate frequency level. Mixing blocks, oscillators, amplifiers, step attenuators, isolators, and filters are included. The input frequency (IF) band is MHz, while the output frequency (radio frequency [RF]) band is MHz. The usage of attenuators increases the dramatic range of the circuit. It is a one‐stage up‐conversion circuit that combines the IF band in one pass to create the appropriate RF spectrum. Here, a single phase‐locked oscillator is employed at the local oscillator port of the mixers, while the other is a programmable frequency generator that generates X‐band frequency channels with a 10 MHz spacing.

Source-Storage-Load Coordinated Master-Slave Control Strategy for Islanded Microgrid Considering Load Disturbance and Communication Interruption.

When there is a sudden load disturbance in an islanded microgrid, the peer-to-peer control model requires the energy resource to maintain a margin of generation, resulting in a relatively limited regulation range, that is, voltage/frequency sometimes requires additional control to maintain stability. A "source-storage-load" coordinated master-slave control strategy is proposed in this study to address the aforementioned issues. The system voltage and frequency will be stable as long as the output frequency and voltage of the master resource are stable. Furthermore, it can fully utilize the power supply capacity of resources to support the supply-demand balance. The following tasks are included in the proposed strategy: 1) to improve the operational security in the face of load disruption, a source-storage-load coordinated control method based on the "ramping speed" ratio is proposed, which can quickly restore the balance of supply and demand; 2) to improve the communication reliability in the face of interruption, a channel planning method is proposed, which can address the communication interruption problem by constructing an internal network among source-storage-load; and 3) to improve the mode switching stability of resources subjected to external disturbance, the external disturbance suppression and stability analysis involved in the regulation process are completed using sliding-mode control and small signal model methods. Related case studies are carried out to verify the effectiveness of the proposed strategies.

The effect of crystal phase noise on the proton precession magnetometer magnetic field measurement accuracy

The proton precession magnetometer is a crucial piece of equipment for measuring magnetic fields because it can determine the value of the magnetic field by measuring the frequency of the Free Induction Decay (FID) signal. The frequency source, one of the crucial parts of the frequency measurement system, has a direct impact on how well the system works as a whole. The communication quality and detection accuracy of the frequency measuring system are directly influenced by phase noise, which is a crucial indicator of frequency stability. By acquiring various output frequencies of crystal oscillators using the Phase Locked Loop (PLL) frequency doubling technique, this study investigates the extent to which crystal phase noise impacts the accuracy of magnetometer frequency measurement.

Concurrent M-QAM transmission performance assessment in a combined four SOA-MZIs arrangement

In this paper, the utilization of four semiconductor optical amplifier Mach-Zehnder interferometers (SOA-MZIs) is explored to achieve concurrent M-QAM (M-ary Quadrature Amplitude Modulation) transmission. Utilizing an actively mode-locked laser, we generate pulses with a duration of 0.5 ps at a repetition rate of 20 GHz, serving as our sampling source. The incoming M-QAM signals, spanning various frequencies, undergo down-mixing at the SOA-MZIs combined exit, resulting in diverse output frequencies by respecting the bandpass sampling procedures. The unparalleled simultaneous M-QAM transmission is assessed through critical metrics such as error vector magnitude (EVM) and bit error rate (BER). The SOA-MZI conversion efficiency (CE) exhibits a notable transition, ranging from 90 % at 76 GHz to 68 % at 84 GHz based on 1024-QAM data. The concurrent down-mixed signals showcase EVM values of 3, 2, 1, and 0.25 % for 16-, 64-, 256-, and 1024-QAM, respectively, at the first range of output frequencies. Besides, an exceptional BER value of 93×10−6 is attained at a symbol rate of 0.25 GSymb/s at 84 GHz for the 1024-QAM replica. A comparative analysis reveals that under identical parameter settings, the proposed Gaussian filter expounds lower EVM values compared to the root raised cosine (RRC) filter. These results highlight the success of the novel experimental approach employing SOA-MZIs for simultaneous down-mixing of four M-QAM carriers with varying levels, showcasing outstanding performance outcomes.

An 80–84.8 GHz PLL with auto-tracking Miller divider for FMCW applications

To generate high frequency signals for frequency modulated continuous wave (FMCW) application, components such as doubler, tripler or multiplier are usually utilized to process further signals from the low frequency voltage controlled oscillator (VCO). In this paper, a phase-locked loop (PLL) is intended to be the primary part used to generate frequency modulated continuous wave (FMCW) signals from 80 to 84.8 GHz by utilizing a fundamental frequency VCO. To divide those high frequency output signal and large output bandwidth, the auto-tracking Miller divider topology is proposed. This new topology can achieve 9 GHz locking range. In order to generate FMCW signals with a straight-line triangular chirp, the cascaded PLL is used. The integrated jitter from 1 kHz to 1 GHz is 887 fs for the cascaded PLL, while the single stage PLL used 1.264 ps. Moreover, when architecture with doubler or multiplier is used, the fundamental tone has an effect towards the next systems, while the cascaded PLL does not. It can be highlighted that this work achieves the best RMS-FMerror/BWchirp and RMS-FMerror/(BWchirp × fc × Tc) with value of 0.013% and 0.77e−12, respectively. The designed PLL for FMCW signal generator is implemented in 28 nm CMOS technology. By using a supply voltage of 1.2 V, the chip consumes power of 102 mW. Including all the chip pads, the implemented circuit occupies a silicon area of 1440 µm × 820 µm.

Automated extraction of heart rate variability from magnetoencephalography signals

Magnetoencephalography (MEG) measures magnetic fluctuations in the brain generated by neural processes, some of which, such as cardiac signals, are generally removed as artifacts and discarded. However, heart rate variability (HRV) has long been regarded as a biomarker related to autonomic function, suggesting the cardiac signal in MEG contains valuable information that can provide supplemental health information about a patient. To enable access to these ancillary HRV data, we created an automated extraction tool capable of capturing HRV directly from raw MEG data with artificial intelligence. Five scans were conducted with simultaneous MEG and electrocardiogram (ECG) acquisition, which provides a ground truth metric for assessing our algorithms and data processing pipeline. In addition to directly comparing R-peaks between the MEG and ECG signals, this work explores the variation of the corresponding HRV output in time, frequency, and non-linear domains. After removing outlier intervals and aligning the ECG and derived cardiac MEG signals, the RMSE between the RR-intervals of each was RMSE1 = 2 ms, RMSE2 = 2 ms, RMSE3 = 8 ms, RMSE4 = 4 ms, RMSE5 = 13 ms. The findings indicate that cardiac artifacts from MEG data carry sufficient signal to approximate an individual's HRV metrics.

Using Cryogenic CMOS Control Electronics to Enable a Two-Qubit Cross-Resonance Gate

Qubit control electronics composed of CMOS circuits are of critical interest for next-generation quantum computing systems. A CMOS-based application-specific integrated circuit (ASIC) fabricated in 14-nm fin field-effect transistor (FinFET) technology was used to generate and sequence qubit control wave forms and demonstrate a two-qubit cross-resonance gate between fixed-frequency transmons. The controller was thermally anchored to the T=4 K stage of a dilution refrigerator and the measured power was 23 mW per qubit under active control. The chip generated single-side banded output frequencies between 4.5 and 5.5 GHz, with a maximum power output of −18 dBm. Randomized-benchmarking (RB) experiments revealed an average number of 1.71 instructions per Clifford (IPC) for single-qubit gates and 17.51 IPC for two-qubit gates. A single-qubit error per gate of ϵ1Q=8×10−4 and a two-qubit error per gate of ϵ2Q=1.4×10−2 were shown. A drive-induced Z rotation was observed by way of a rotary-echo experiment; this observation is consistent with the expected qubit behavior given the measured excess local-oscillator (LO) leakage from the CMOS chip. The effect of spurious drive-induced Z errors was numerically evaluated with a two-qubit model Hamiltonian and shown to be in good agreement with the measured RB data. The modeling results suggest that the Z error varies linearly with the pulse amplitude. Published by the American Physical Society 2024

A current-configurable charge pump with current mismatch compensation for wide output frequency range phase-locked loop

To ensure the loop stability of a wide output frequency range phase-locked loop (PLL), a current-configurable technique for a charge pump (CP) is utilized to reduce the variation of PLL phase margin within a wide frequency range. An isolation transistor is inserted into a traditional current steering CP to improve the clock accuracy and reduce degradation of the PLL lock-in speed caused by switch control signal crosstalk on the output voltage. Furthermore, a feedback-based compensation technique is developed to reduce the mismatch between the charging and discharging currents of the proposed CP, thereby improving PLL output clock accuracy. Based on these techniques, a CP circuit is designed with 0.18 μm CMOS technology and occupies an active area of 0.005 mm2. Simulation results from different process corners operated at 1.8 V show that the maximum mismatch between the charging and discharging currents of the CP decrease from 2 % to 0.6 % when the CP current is 10 μA over a temperature range from −40 ℃ to 85 ℃. The CP is used in a PLL with input and output frequencies of 25–100 MHz and 25–500 MHz, respectively. The worst phase margin of the PLL is improved from 31° to 52.3° by configuring the CP current over a range from 10 to 40 μA. The output clock accuracy of the PLL is optimized from 600 to 100 Hz/MHz under input and output frequencies of 100 and 500 MHz, respectively.

Использование программно-определяемого радио для структурного анализа энергоемких веществ с помощью ядерного магнитного резонанса

This article discusses the creation of a system using software-defined radio for the study of energy-intensive substances using nuclear magnetic resonance. Software-defined radio (SDR) uses technology that allows to configure or change the parameters of radio frequency operation through software, such as frequency range, modulation type and output power. The article presents the structure of the system and provides a detailed analysis of several key components. The proposed approach involves the use of a SDR transmitter-receiver, which is a universal device capable of both transmitting and receiving signals. The article describes the stages of signal processing and suggests potential directions for the development of the system in the future. By using the SDR architecture and software interface, the system achieves a close location between sampling, digital-to-analog and analog-to-digital conversions, minimizing noise and distortion created by the analog part of the spectrometer. The SDR allows the use of quadrature modulation and demodulation, digital filtering and amplification, as well as software adjustment of filter characteristics. The article highlights the problems associated with the development of such NMR systems. The advantages of the system include enhanced capabilities for the development of new spectroscopic methods, compact dimensions for easy portability and cost-effectiveness compared to commercial spectrometers.

Flexible Unipolar IGZO Transistor-Based Integrate and Fire Neurons for Spiking Neuromorphic Applications.

In this article, three different implementations of an Axon-Hillock circuit are presented, one of the basic building blocks of spiking neural networks. In this work, we explored the design of such circuits using a unipolar thin-film transistor technology based on amorphous InGaZnO, often used for large-area electronics. All the designed circuits are fabricated by direct material deposition and patterning on top of a flexible polyimide substrate. Axon-Hillock circuits presented in this article consistently show great adaptability of the basic properties of a spiking neuron such as output spike frequency adaptation and output spike width adaptation. Additional degrees of adaptability are demonstrated with each of the Axon-Hillock circuit varieties: neuron circuit threshold voltage adaptation, differentiation between input signal importance, and refractory period modulation. The proposed neuron can change its firing frequency up to three orders of magnitude by varying a single voltage brought to a circuit terminal. This allows the neuron to function, and potentially learn, at vastly different timescales that coincide with the biologically meaningful timescales, going from milliseconds to seconds, relevant for circuits meant for interaction with the environment. Thanks to careful design choices, the average measured power consumption is kept in the nW range, realistically allowing upscaling towards the spiking neural networks in the future. The spiking neuron with refractory period modulation presented in this work has an area of 607.3 μm × 492.2 μm, it experimentally demonstrated firing rates as low as 11.926 mHz, and its energy consumption per spike is ≈ 700 pJ at 30 Hz.

Active control of thermoacoustic oscillation based on the x-nlms algorithm

Thermoacoustic oscillations, caused by the coupling of unsteady heat release and pressure fluctuation, can result in severe damage to the combustion chamber of gas turbines. This paper presents a novel approach to active control of thermoacoustic oscillations, which is based on a Filtered-X normalized least mean square algorithm (X-NLMS). The controller employs the pressure magnitude at a predetermined axial position preceding the flame as the control variable, which is acquired through microphones installed around the combustor periphery. Control is accomplished by modifying the output frequency and phase of a loudspeaker. The performance of the control system is evaluated through simulations on a Rijke tube, with the classical PID method used as a comparison. The experimental results showcase the efficacy of the X-NLMS algorithm in actively controlling thermoacoustic oscillations. By adaptively estimating and attenuating pressure fluctuations, the algorithm effectively suppresses the undesired acoustic disturbances associated with thermoacoustic instabilities. Comparative analysis reveals that the X-NLMS algorithm outperforms PID control in terms of oscillation suppression and system stability. Its ability to adapt to time-varying dynamics and its low computational complexity make it a promising candidate for real-time thermoacoustic control applications.

An estimation method of normalized nonlinear output frequency response functions for fatigue damage detection using stochastic response signal

AbstractNonlinear output frequency response functions (NOFRFs) and its modified version, normalized NOFRFs (norm‐NOFRFs), are composed of multiple spectra, which can sensitively indicate the occurrence of fatigue damage in machinery. However, their application is restricted to a certain extent. Currently, neither NOFRFs nor norm‐NOFRFs can be estimated with only a single response signal. Aimed at this problem, the nonlinear auto‐regressive (NAR) model was introduced, and an estimation method of norm‐NOFRFs is proposed in this paper. Only one stochastic response signal is required in the proposed method, which removes the restrictions on the number and intensity of signals to identify norm‐NOFRFs, and expands the range of scenarios for using norm‐NOFRFs in damage detection. The feasibility and robustness of the proposed method are verified by the nonlinear model in numerical simulation. The effectiveness of revealing and quantifying the fatigue damage is verified by experimental study for three kinds of mechanical parts.

A Modified Particle Swarm Algorithm for the Multi-Objective Optimization of Wind/Photovoltaic/Diesel/Storage Microgrids

Microgrids have been widely used due to their advantages, such as flexibility and cleanliness. This study adopts the hierarchical control method for microgrids containing multiple energy sources, i.e., photovoltaic (PV), wind, diesel, and storage, and carries out multi-objective optimization in the tertiary control, i.e., optimizing the economic cost, environmental cost, and the degree of energy utilization of microgrids. As the traditional multi-objective particle swarm algorithm is prone to local convergence, this study introduces variable inertia weight and learning factors to obtain a modified particle swarm algorithm, which is more advantageous in multi-objective optimization. Compared to the traditional particle swarm algorithm, the modified particle swarm algorithm increased the photovoltaic absorbed rate from 0.7724 to 0.8683 and the wind energy absorbed rate from 0.6064 to 0.7158 in one day, which resulted in an increase in energy utilization by 14.89%, and a reduction in financial environmental costs from RMB 135,870 to RMB 132,230. The simulation of the optimization effect of the conventional particle swarm algorithm and the modified particle swarm algorithm on the microgrid were carried out, respectively, in MATLAB, which verifies the advantage of the modified particle swarm algorithm on the optimization of microgrids. Then, the optimization results, i.e., the data of the power scheduling process of the four power sources, were made into a table and imported into the microgrid model in Simulink. The simulation results indicated that the microgrid was able to output stable voltage, current, and frequency. Finally, the changes in microgrids affected by the external environment were further investigated from the aspects of the market environment and natural environment. Moreover, we verified the presence of a contradiction between the optimization of the microgrid economy and environmental protection. Thus, microgrids need to adjust their optimization focus according to the natural conditions in which they are located.

Evaluation of Smoothing Effect of Wind Power Generator Aggregation on Power System Operation

This paper presents an approach to evaluate the smoothing effect of wind power generators on power system operation based on actual wind output data in Tohoku area in Japan. Conventional LFC (Load Frequency Control) model is used and the effect of the smoothing effect on frequency control is evaluated. For evaluating the smoothing effect, spectral analysis and integration of each frequency of wind outputs are utilized. In this study, the smoothing effect in multi areas is evaluated and the decrease of the power spectrum density of individual wind generator is confirmed by comparing with the density of integrated wind generators in wide areas. Moreover, we assume many wind generators are connected to power systems, and analyze the smoothing effect of integrating wind power generators on power system operation. By using this multi generator model, the influence of generator integration on the LFC is evaluated by investigating the change of frequency deviations. In addition, a method to suppress the frequency deviation caused by wind power fluctuations is proposed with control of batteries equipped in Electric Vehicles (EVs)’ in the power system model consists of wind generators and EVs.

Multi-objective Agent Model for XGBoost Controlled VFTO Simulator Based on Bayesian Optimization Algorithm

VFTO generated from GIS may cause interference and damage to terminal equipment on the primary and secondary sides, but experimental measures to evaluate the affected equipment and electromagnetic effects of the equipment through actual measurements are quite limited, so it is desired to build a VFTO simulator in the laboratory for experimental research and laboratory testing. Most of the current researches are conducted by building a true-type experimental platform for VFTO simulation, but this method has the disadvantages of large footprint, high cost and the scope of application can only simulate VFTO in a certain situation. Therefore, this paper establishes a broadband circuit model considering the pulse generator and the frequency domain equivalent transmission line model, and introduces the machine learning algorithm XGBoost to fit the agent model of the functional relationship between the design target and the structural parameters by establishing the sample data of the input circuit parameters and the output frequency waveform characteristics of the simulator, which is capable of dynamically adjusting the input parameters based on the waveform characteristics according to the changes of the target waveform, and ensures that a controllable waveform is obtained accurately in the laboratory the accuracy of obtaining controllable waveforms, thus realizing the output of controllable analog VFTO waveforms by changing the parameters of circuit components. Finally, the Bayesian optimization process is used for the hyper-parameter optimization of the XGBoost model, which has a fast convergence speed, and the characteristics of the output model are compared and analyzed, which verifies the feasibility and superiority of the proposed agent model as well as the multi-objective optimization method.