Search

In this paper, we show the feasibility of improving the performance of a high voltage and high repetition avalanche transistor pulse generator by applying a two-phase immersion cooling technique. The forced air cooling, single-phase immersion cooling, and two-phase immersion cooling technique was applied to a 60-stage sub-nanosecond pulse generator. The experimental results indicate that the two-phase immersion cooling technique can effectively control the temperature rising and thus reduce the time base jitter and voltage amplitude jitter. Five types of dielectric fluid with different boiling temperatures were comparatively studied. The FC-72 was finally adopted for the balanced performance on voltage amplitude and repetition rate. The two-phase immersion cooling technique could reduce the thermal resistance between the case and ambient, and increase the power from 330mW to 876mW. With this cooling method, the surface temperature of the transistor can be effectively controlled below 62. The pulse generator could achieve outstanding performance with a voltage of 2350 V and a rise time of 180 ps. It can work stably at 200 kHz for more than 30 minutes, and the burst repetition rate could be 260 kHz within one minute. This work offers new perspectives in high repetitive avalanche transistorized sub-nanosecond generators.

This article presents analysis, design details, and measurement result of a 224-Gb/s four-level pulse amplitude modulation (PAM-4) transmitter (TX) consisting of a 7-bit voltage digital-to-analog converter (DAC) driver, digital 8-tap feed-forward equalizer (FFE), and a 28-GHz inductively peaked clock distribution network. The TX DAC uses quarter-rate clocking with a 4:1 pulse-based data serialization architecture. Design techniques for generating and distributing low-jitter CMOS clocks up to 29 GHz, timing closure in the serializer, 112-Gbaud 4:1 data MUX using 1-UI pulse generator, and bandwidth/return loss/group delay optimized output pad network using a 9th-order LC filter are described. Fabricated in the Intel 10-nm FinFET process technology, the TX demonstrates random jitter (RJ) of 65 fs $_{{rms}}$ with nominal output swing of 1.0 $V_{{ppd}}$ at 224 Gb/s achieving 1.88-pJ/b energy efficiency including an on-die LC phase-locked loop (PLL). To the best of authors' knowledge, this TX achieved the highest data rate with the lowest RJ for CMOS SerDes TXs reported to date.

Rectifier is the most critical block of the power conditioning circuit designed for the Piezoelectric Energy Harvester (PZEH). Maintaining high rectification efficiency under the variable ambient conditions is the major design challenge. This paper presents a novel topology of self tuned Synchronized Switch Harvesting on Inductor (SSHI) based rectifier circuit for PZEH which provides high power extraction efficiency over a wide range of frequency and magnitude of input vibrations available. The high rectification efficiency is maintained for different PZ devices also. The synchronization of SSHI block under different ambient conditions is achieved by an adaptively controlled pulse generator circuit which uses internal voltage sensing. An active diode circuit to reduce the conduction loss in SSHI block and forward voltage drop of rectifier is used. The proposed circuit is working from 100 to 350 Hz with flipping efficiency above 90% and power extraction efficiency around 50%. A maximum power conversion efficiency of 58 % and maximum flipping efficiency of 93.6% is obtained with a figure of merit of 467% and output power of $$72.6\,\mu \hbox {W}$$ .

Objective A recently introduced Spinal Cord Stimulation (SCS) system operates at 10 kHz, faster than conventional SCS systems, resulting in significantly more power delivered to tissues. Using a SCS heat phantom and bioheat multi-physics model, we characterized tissue temperature increases by this 10 kHz system. We also evaluated its Implanted Pulse Generator (IPG) output compliance and the role of impedance in temperature increases. Materials and methods The 10 kHz SCS system output was characterized under resistive loads (1-10 KΩ). Separately, fiber optic temperature probes quantified temperature increases (ΔTs) around the SCS lead in specially developed heat phantoms. The role of stimulation Level (1-7; ideal pulse peak-to-peak of 1-7mA) was considered, specifically in the context of stimulation current Root Mean Square (RMS). Data from the heat phantom were verified with the SCS heat-transfer models. A custom high-bandwidth stimulator provided 10 kHz pulses and sinusoidal stimulation for control experiments. Results The 10 kHz SCS system delivers 10 kHz biphasic pulses (30-20-30 μs). Voltage compliance was 15.6V. Even below voltage compliance, IPG bandwidth attenuated pulse waveform, limiting applied RMS. Temperature increased supralinearly with stimulation Level in a manner predicted by applied RMS. ΔT increases with Level and impedance until stimulator compliance was reached. Therefore, IPG bandwidth and compliance dampen peak heating. Nonetheless, temperature increases predicted by bioheat multi-physic models (ΔT = 0.64°C and 1.42°C respectively at Level 4 and 7 at the cervical segment; ΔT = 0.68°C and 1.72°C respectively at Level 4 and 7 at the thoracic spinal cord)-within ranges previously reported to effect neurophysiology. Conclusions Heating of spinal tissues by this 10 kHz SCS system theoretically increases quickly with stimulation level and load impedance, while dampened by IPG pulse bandwidth and voltage compliance limitations. If validated in vivo as a mechanism of kHz SCS, bioheat models informed by IPG limitations allow prediction and optimization of temperature changes.

To satisfy ever higher kick strength requirements in reduced space, present and future fast kicker magnets in particle accelerators must often be of short-circuited delay line type, despite the full voltage reflection produced. Three EEV ceramic thyratrons, types CX 1154 (single-gap), CX 1168 (double-gap) and CX 1171 (triple gap) have been tested in inverse diode mode in a cable PFN pulse generator to absorb these reflections. The single-gap tube operated without difficulty if triggered prior to the reflection arrival. The refusal voltage was then limited to 2 kV during a few tens of nanoseconds. The double and triple-gap tubes required an extra R-C arrangement on their gaps closest to the anode to operate as inverse diodes. They then exhibited low refusal voltage (respectively 4.kV and 6 kV during some 30 ns) but only when the operating voltage was higher than 35 W. Pre-triggering had no beneficial effect. These results are discussed in terms of their acceptability for the different kicker magnet applications encountered in present-day synchrotron complexes.

Nonlinear transmission lines (NLTLs) provide a means to generate high-repetition-rate, high-power microwaves with fewer auxiliary systems than conventional sources. They are typically driven by pulse forming networks (PFNs) or Marx generators, and one would intuitively hypothesize that the microwave generation would not depend significantly on the method used to generate the input pulse to the NLTL. This study examines the implications on microwave output by using a Blumlein pulse generator with a 10-ns pulse duration and 1.5-ns rise and fall times to drive coaxial NLTLs produced using composites with nickel zinc ferrite and barium strontium titanate (BST) inclusions. Applying a 30-kV pulse to the composite NLTLs produced frequencies ranging from 1.1 to 1.3 GHz with output powers over 20 kW. The output frequencies increased with increasing volume fraction of BST. Measured results and simulations using LT SPICE showed that Blumlein modulators were insufficient to drive NLTLs to produce high-power oscillations; however, LT SPICE simulations showed that applying a standard PFN to the same NLTL produced the expected oscillations. This difference arises because the mechanism for Blumlein pulse formation cancels the shockwaves responsible for inducing microwave production by the NLTL.

We characterize the frequency response of channel-interleaved photonic analog-to-digital converters (CI-PADCs) theoretically and experimentally. The CI-PADC is composed of a photonic frontend for photonic sampling and an electronic backend for quantization. The photonic frontend includes a photonic sampling pulse generator for directly high-speed sampling and an optical time-division demultiplexer (OTDM) for channel demultiplexing. It is found that the frequency response of the CI-PADC is influenced by both the photonic sampling pulses and the OTDM, of which the combined impact can be characterized through demultiplexed pulse trains. First, the frequency response can be divided into multiple frequency intervals and the range of the frequency interval equals the repetition rate of demultiplexed pulse trains. Second, the analog bandwidth of the CI-PADC is determined by the optical spectral bandwidth of demultiplexed pulse trains which is broadened in the OTDM. Further, the effect of the OTDM is essential for enlarging the analog bandwidth of the CI-PADC employing the photonic sampling pulses with a limited optical spectral bandwidth., Comment: 11 pages, 8 figures

This brief presents a low-power counter-based adaptive equalizer that does not require additional power-hungry comparators for an equalizer adaptation loop. A pulse generator in the proposed equalizer obviates the need for additional error sampling comparators. Instead, it allows the receiver to utilize an output of a data decision comparator for the equalizer adaptation by generating a pulse that indicates whether the comparator makes a firm decision for the incoming data. A single comparator is shared by the data recovery path and equalizer adaptation loop. Consequently, the proposed counter-based equalizer achieves a low power dissipation owing to the reduced number of comparators. Fabricated in a 28-nm CMOS technology, the prototype receiver occupies an active area of 0.004 mm2 and consumes only 0.99-pJ/b at 15-Gb/s.

The proposed compact solid-state modulator for the generation of high-power electromagnetic (HPEM) pulses uses a lithium polymer battery as the input power source and is capable of achieving a 100-Hz pulse discharge rate with a peak voltage of 400 kV for 2 min. The developed pulse generator consists of two charging units. The primary charging unit is designed to work with 200-A battery current, which increases switching losses and temperature increments at the main switch. To compensate the problems, a half-bridge three-phase structure is connected to transformers via the proposed delta-star connection that decreases the turns ratio of the three-phase transformer effectively. Furthermore, the resonant components are intentionally placed on the secondary side of the three-phase transformer, which is characterized by low current and high voltage conditions. The secondary charging unit uses the resonance between the two capacitors, and the inductor must protect not only the controller, which is susceptible to HPEM pulse effects, but also the output rectifying diodes of the primary charging unit from the peak 20-kA pulse discharging effect. The design procedures and analysis are verified with simulations for each charging unit. The experimental results using various loads, including the actual tesla transformer, validate the system performance and confirm a 94% power efficiency with a peak power density of 431 W/L.

A real-time digital time-stamp sorting algorithm used in the In-Beam positron emission tomography (In-Beam PET) is presented. The algorithm is operated in the field programmable gate array (FPGA) and a small amount of registers, MUX and memory cells are used. It is developed for sorting the data of annihilation event from front-end circuits, so as to identify the coincidence events efficiently in a large amount of data. In the In-Beam PET, each annihilation event is detected by the detector array and digitized by the analog to digital converter (ADC) in Data Acquisition Unit (DAQU), with a resolution of 14 bits and sampling rate of 50 MS/s. Test and preliminary operation have been implemented, it can perform a sorting operation under the event count rate up to 1 MHz per channel, and support four channels in total, count rate up to 4 MHz. The performance of this algorithm has been verified by pulse generator and 22Na radiation source, which can sort the events with chaotic order into chronological order completely. The application of this algorithm provides not only an efficient solution for selection of coincidence events, but also a design of electronic circuit with a small-scale structure.

Abstract A high-voltage pulse generator is considered that contains an output circuit based on series-connected assemblies of reverse switched-on dynistors and drift step-recovery diodes. It forms voltage pulses with a rise time of 4 ns and an amplitude of 24 kV across a load of 50 Ω. The results of using the generator for creating discharges in atmospheric air are presented. The generator forms discharge-current pulses with an amplitude of 1.7 kА and a rise time of 900 ns at a frequency of 100 Hz and switches an energy of ~3 J to the charge channel. The possibility of a significant increase in the switched energy has been shown.

The pulse generators were developed to trigger the high-voltage dischargers of magnetic systems and the dischargers of the generators of pulsed voltages used by the relativistic electron beam (REB) accelerator “TEMP-B”. The description of the triggering pulse generators designed by the NSC KIPT to actuate the dischargers of the pulsed voltage generators (PVG) and the dischargers of magnetic systems has been given. These are used by the commutation systems of capacitor banks with the stored energy margin in the range of 60 to 150 kJ. The generators provide the generation of voltage pulses with the amplitude of up to 20 kV.

This brief presents an on-off keying (OOK) driven impulse radio ultra-wideband (IR-UWB) pulse generator (PG) for 3–5 GHz applications, featuring high sidelobe suppression (SLS), large bandwidth ( $BW_{-10dB}$ ), and robustness against process variations. To eliminate the need for a dedicated off-chip pulse-shaping filter, a transistor-sizing-based pulse shaping scheme is adopted to generate a broadband pulse with a triangular envelope, ensuring enhanced SLS with extended signal bandwidth. The proposed process compensating circuit mitigates the effects of process variations on the propagation delay of the logic gates to provide stable pulse timing characteristics. Implemented in 65-nm CMOS process, the prototype PG provides a UWB pulse with an amplitude of 634 ${\mathrm {mV}}_{pp}$ , $BW_{-10dB}$ of 1.12 GHz, and 27 dB SLS, while occupying a total chip area of 964 $\mu \text{m}\,\,\times $ 669 $\mu \text{m}$ . The proposed PG provides enhanced pulse characteristics with modest energy consumption among the reported works. Based on the proposed figure-of-merit considering the SLS and quality of pulse, the PG in this work shows a competitive FOM of $3.36\times 10^{9}$ .

The nanosecond short pulse generator, which operates continuously at MHz repetition rates, plays an important role in high-energy accelerators, pulsed laser modulation, electromagnetic biological effects, and other fields. Pulse-forming lines based on gas spark gap are the main means to generate high-voltage nanosecond short pulses; but due to electrode ablation, it is difficult to operate at MHz repetition rates. The topologies based on the fully controlled semiconductor device can output multimode nanosecond pulse. But it is limited by the gate driver ability and system stray loss, so it is difficult to directly generate flexible and adjustable nanosecond short pulse with MHz repetition rates. In order to overcome the above shortcomings, this article proposes the Blumlein-based LC underdamped oscillation boost circuit and the Blumlein stack topology to achieve high voltage gain. And, the voltage wave process can be adjusted by controlling the switching sequence to change operating mode. Finally, multimode operation such as positive polarity, negative polarity, bipolar and pulse duration modulation can be realized with MHz repetition rates and high gain voltage.

This article puts forward a high repetition rate and high-voltage resonant pulse generator for plasma-assisted milling. This circuit uses only one semiconductor switch with an antiparallel diode and works in the resonant mode with the help of a resonant inductor, a resonant capacitor, and a pulse transformer to generate high-voltage pulses. An equivalent circuit of the proposed topology considering parasitic elements is established. Based on the equivalent circuit, the working principle of the pulse generator is analyzed in detail. In order to verify the theoretical analysis and circuit operation, a laboratory prototype with a 150-V dc input is implemented. The pulse repetition rate can be adjusted from 5.32 to 18.90 kHz, and the peak output voltage correspondingly varies between 8.84 and 11.7 kV. The pulse generator is used to drive a dielectric barrier discharge plasma-assisted milling chamber. Experimental results show that the pulse generator can work stably.

Purpose The nano-router would be a mastery device for providing high-speed data delivery. Here nano-router with a space-efficient crossbar scheduler is used for making absolutely less consumption in power. Design/methodology/approach In the emerging modern technology, every one of us is expecting a delivery of data at a high speed. To achieve high-speed delivery the authors are using the router. The router used here is at nanoscale reading which provides a compact size. Findings This can be implemented using the modern tools called Quantum-dot Cellular Automata (QCA) which is operated without the use of a transistor. As conventional complementary metal oxide semiconductor (CMOS) designs have some limitations such as low density, high power consumption and requirement of a large area. Research limitations/implications To overcome these limitations the QCA is used. It characterizes capability is used to substituting CMOS technology. The round-robin fashion is used in a high-speed space-efficient crossbar scheduler. Practical implications The simulation of the planned circuit with notional information established the practical identity of the scheme. Social implications The proposed nano router can be stimulated in the QCA environment using the QCADesigner tool and the power of the router can be calculated with the QCADesigner–E tool. Originality/value The proposed nano router can be stimulated in the QCA environment using the QCADesigner tool and the power of the router can be calculated with the QCADesigner–E tool. In this work, the performance of the router can be done in both the QCA environment and CMOS technology.

Nanosecond pulse output at megahertz level is wide interest because of its potential application in the experiment of cell function electric field regulation and accelerator electron gun injector. In this article, a pulse generator based on the combination of the Blumlein pulse forming line and the boost method is proposed. Different from the traditional Blumlein line, in this module, the RLC circuit is used to improve the pulse voltage amplitude and energy conversion efficiency. According to the different inductance values, the generator has two working modes: discontinuous and continuous with different output characteristics. RF-Si- mosfet is used as the main switch and used dual-switch timing logic control to adjust the output waveform parameters. It can obtain the output pulse frequency two times the switching frequency, effectively reducing the single switching loss. By constructing a prototype, the pulsewidth of 5 ns, maximum repetition of 10 MHz and 2.5-kW peak power is realized. In addition, a dc equivalent pulse method is proposed, which is suitable for the thermal simulation of switching at high frequency and gives the heat dissipation measures. The effectiveness is verified by simulation and experiment.

Nonlinear transmission lines (NLTLs) are a class of pulse forming networks (PFNs) for modulation of pulsed power to generate radio frequency (RF) signals. Primarily, NLTL designs assume a two-port configuration, which requires ones-to-tens of nanosecond input pulse rise time for each modulated pulse out. In this article, a closed-loop or single-port pulser that yields continuous pulses based on prior pulse stimulation is presented. The pulser is comprised of an NLTL, a power amplifier (PA), and a solid-state HV pulse generator. The capability advantage of the closedloop system is its stability and center frequency tunability. Pragmatically, the solid-state-based design of this system enhances its probability of fielded use due to volume and mass savings compared to the prior art. The validity of the proposed design is empirically shown by a 16-section NLTL coupled with a solid-state laterally diffused metal–oxide–semiconductor (LDMOS)-based PA and a custom HV pulse generator. The closed-loop configuration constructed from these components demonstrated a peak power of 2.1 kW into 50 $\Omega $ at 90 MHz. This is the first report of a solid-state switch-based closed-loop NLTL configuration capable of producing a continuous pulse stream. Furthermore, we propose a dual-diode-based NLTL design, which can operate and output at higher center frequencies compared to its single-diode counterpart.

The rising edge of the output pulses affects the discharged mechanism and efficiency of the nonthermal plasma generation. In the traditional Marx-type pulse generators, the magnetic isolation driving circuit could not adjust the rising edge of the output pulses and limits the application on a capacitive load. In this article, the factors affecting the rising edge of output pulses are analyzed. And a driving circuit based on magnetic isolation is proposed, which can control the rising edge of the output pulses. A synchronous driving signal is used to control multiple groups of switches using different sequences, and the magnetic core does not limit the driving signals. The experiments were carried out using a seven-stage solid-state Marx modulator. From the results, the rectangular pulses and stepped pulses are obtained at a capacitive load, and the 0.1– $2.3~\mu \text{s}$ adjustment rising edge can be obtained under 0–5 kV output voltage.

This brief presents the design and implementation of an energy efficient high-voltage (HV) pulse generator for MEMS capacitive sensors and actuators. The core circuit of the proposed HV pulse generator consists of four dual-mode switched-capacitor voltage doublers (D-SCVDs). Dynamic output impedance (DOI) method is proposed and implemented to improve energy efficiency during the rising edge generation. Load energy recycling (LER) method is also used during the falling edge generation to reduce the overall energy consumption. The proposed circuit achieves an end-to-end energy efficiency of 43.5% with 250 kHz driven frequency under 550 pF capacitive load and 3.3V supply. The maximum pulsing voltage achieves 15.4V and standby power is measured as 9.8 nW. The proposed design is implemented in SMIC standard $0.18\boldsymbol{\mu }\text{m}$ CMOS process occupying a core area of $700\boldsymbol{\mu }\text{m}$ by $800\boldsymbol{\mu }\text{m}$ .

The application of inductive energy storage in the generation of high-current pulses has attracted considerable attention during recent years. In this article, a new inductive high-current pulse generator circuit is proposed based on XRAM (MARX spelled backword) current multiplier converter concept and multistage pulse transformers by using power electronic switches. This circuit is capable to recover the residual energy and generate repetitive high-current pulses with a flexible output pattern. To verify the circuit operation, simulation and experimental results of a two-stage laboratory prototype are presented. The results confirm the theoretical analysis and show the validity of the converter scheme.

A phenomenon that transiently increases the permeability of the cells is known as electroporation. It is the basis for number of the applications in biomedical domains. It is essential to consider requirement of high precision and the overall size of electroporator. The recent decades have seen the development of solid-state power electronic modules. The modules enable generation of high voltage millisecond and nano-second pulses with options to reduce the overall size of the equipment. The selective modules are verified with experimental models and available for commercial usage. While the other modules are still undergoing optimization processes. The generator generates pulses for varying performances. Hence, this paper presents knowledge for different nanosecond and millisecond pulse generating circuits for electroporation purposes. The performance parameters like the width of the pulse, its amplitude are compared for different circuit topologies. The performance analysis of different topologies and their impact on the performance of the electroporation at the cell biology level are considered in this paper.

Plasma application systems can be classified as an inductive-coupled plasma (ICP) system and a capacitive coupled plasma (CCP) system. Generally, a voltage-source-type pulse generator (VST-PG) is utilized in ICP systems. The VST-PG has the intrinsic problem of spike currents and voltage ringing in CCP systems. A filter inductor and damping circuit have been employed to mitigate this problem. However, this solution degrades the dynamic performance and increases the system cost, particularly for a CCP system with a large power rating. This article proposes a current-source-type pulse generator (CST-PG) to solve the problem of current spike and voltage ringing in a CCP system. The proposed circuit structure provides the output voltage and current waveform of the enhanced waveform fidelity. In the proposed system, two current sources of different scales are connected in parallel to generate the output current with high precision. The entire system consists of four major functional blocks: a bias current generator, a bias current modulator, a slope current generator, and a slope current modulator. The proposed solution also employs a SiC mosfet -type power semiconductor switch of 1200 V/90 A to meet the fast transient requirement. The proposed converter system successfully satisfies the specification of an output voltage of 1.6 kV and an output current of 35 A with a fundamental frequency of 100 kHz. The experimental validation result confirms the superior performance of CST-PG with a reduced crest factor of 1.12 for a laboratory prototype.

Trigger injection and its influence on performances of a single-gap pseudospark switch were studied by using a high-dielectric trigger unit and two types of pulse generators, where pulse parameters, polarity effect, anode voltage, and electrode geometries were varied. It is found that pulses with the rising edge of nanosecond scale can cause diffused electron emission in a large region of the trigger unit, while the slower pulses result in a localized surface flashover. The trigger injection is strongly polarity-dependent, and the way of applying the negative pulse voltage to the outer electrode is more favorable. Not all injected electrons can contribute to the triggering process, and the only factors that can lead to higher charge quantity and energetic components of electrons with a short injection delay are helpful to reduce the trigger delay. A model considering the potential penetration is presented to explain the influence of trigger injection, anode voltage, and electrode geometries. When trigger injection is strong enough or the ratio of cathode hole diameter to its thickness is relatively large, the trigger delay remains constant at different anode voltage; otherwise, it decreases as the anode voltage increases.

SiC-MOSFET has been widely used in nanosecond pulse power generators due to its excellent switching characteristics. The solid-state Marx generator using SiC-MOSFET has the advantages of modularity, flexible adjustment, and economic reliability. However, due to the limitation of the busbar loop’s parasitic inductance, the excellent switching characteristics of SiC-MOSFETs have not yet been fully utilized in solid-state Marx. This article discusses the PCB wiring structure of the single-module of solid-state Marx and the influence of its superimposed spatial distribution parameters on the output pulse waveform. The principle of 3-D busbar structure and mutual inductance cancellation method to reduce the parasitic inductance of pulse busbar loop is proposed. And verify the above principle through electromagnetic simulation and four-stage superposition experiment. The parasitic inductance of the busbar loop is less than 4 nH. The voltage edge of the output pulse is further reduced, the current rise/fall speed is increased by about 2.3 times, and the switching voltage overshoot is reduced by 80%. And the proposed structure effectively suppresses the gate bounce and improves the solid-state Marx pulse characteristics. Finally, the stability and reliability of the system are improved too.

The good performance of a clock generator circuit in the power supply for triger TTL IC is very influential on the success of the lab. A series. Therefore, the effectiveness of use must be adapted to its use in the practicum. To create a clock generator circuit as a source of pulses from a digital counter IC, a timer IC can be used. This pulse generator or clock generator can be used for clock sources in making counters up and down. Clock generators are often referred to as clock generators. The pulse generator in making the circuit is often used linear integrated circuit (IC: Integrated Circuit). A linear IC that is commonly used in general is usually the NE555 which is a timer IC. As a timer it can also be used analogically as a Clock Generator or pulse generator which can generally generate the frequency or time as needed.

Emerging trends toward miniaturization and growing demands have led to fabricate the nanofeatures size product for electronics, robotics, aeronautics, biomedical, automobile, and Bio-MEMS sectors. ...

The need for technology and technology has led to a sharp acceleration of experimental design and research work to study in an ultrahigh vacuum environment, both surface and bulk properties of solids. The accumulation of basic knowledge about surfaces, especially semiconductor materials, makes it possible to develop modern semiconductor devices in electronics and microelectronics. In this work, a time-of-flight mass spectrometric setup is proposed, the use of which makes it possible to obtain objective information about such processes as adsorption and desorption on the surface of semiconductors. Mass spectrometry is a physical method for analyzing the composition of complex mixtures of substances and identifying individual substances in them by their mass spectra. The mass spectrum is obtained as a result of ionization of substances, separation of ions according to their mass numbers (the ratio of the mass of an ion to its charge) and measurement of the intensity of ion currents for all ions. The mass spectrum allows conclusions to be drawn about the molecular weight of the sample, its composition and structure. The study of adsorption processes makes it possible to qualitatively change the conditions on the surface of semiconductors, which in turn change the energy spectrum of electrons in the near-surface region and leads to the production of both efficient photocathodes with negative electron affinity and an MIS structure with specified parameters. The novelty of this setup lies in the fact that, along with the existing standard units, blocks and devices (a rectangular pulse generator that controls the power supply of an electron gun, an ion source, an electron multiplier for registering ions by masses, a pulse broadband amplifier, a gate signal delay unit, valve, integrator and indicator) are used in order to increase the speed, accuracy and reliability of measurements. Recommended additionally a waiting square-wave generator, two pulse expanders and a comparison unit, while the input of the waiting square-wave generator is connected to the output of the master pulse generator, and its two outputs are connected to the inputs of pulse expanders, the outputs of which are connected to the inputs of the comparator connected with their output to the stroboscopic signal delay unit, they can qualitatively improve the operation of the installation.

Abstract The prospect of using high-voltage GaAs drift step-recovery diodes for the formation of subnanosecond pulses is shown. The electrical circuit of a generator is described, which provides (with a total efficiency of at least 25%) the formation of pulses at a load of 50 Ω with an amplitude of up to 550 V, a voltage rise time of 0.43 ns, a full width at half maximum of 0.73 ns, and a repetition frequency of up to 200 kHz.

This article describes a modification and an experiment conducted on a solid-state pulsed power modulator (SSPPM) for medical linear particle accelerator (LINAC) applications. Depending on the operating condition of the magnetron, an existing design of an insulated-gate bipolar transistor (IGBT)-based modulator is modified, from a positive pulse generator to a negative pulse generator. The design of the gate driver circuit of the pulse discharging IGBTs is also slightly changed to secure reliability against the arc condition. The developed modulator has the following maximum output—pulse voltage of −40 kV, pulse current of −100 A, pulsewidth of 5 μ s, and pulse repetition rate of 250 Hz. By adapting the proposed design to the pulsed power modulator for driving the magnetron, high peak and average power densities of 43 kW/L and 48.9 W/L, respectively, can be achieved. The experimental results from various tests conducted using a resistor load, including a rated operation and an arc protection, verify the robustness and utility of the developed SSPPM for medical LINAC applications. An experiment using a 9.3-GHz 1.7-MW X-band magnetron is also conducted. The developed modulator achieved a successful arc protection operation for the arc generated in the waveguide during the magnetron drive test.

With the development of high-power microwave technology, the output power of the pulse generator is required more and more higher. In this paper, it is realized by increasing the output power of the module while the output impedance of the module changes little. The module of the generator is based on pulse forming network (PFN) and linear transformer (LT). Four Blumlein PFNs with arc-type configuration and 24 Ω characteristic impedance were connected symmetrically to the primary coil of the LTD and driven by two identical laser triggered spark switches to ensure four Blumlein PFNs synchronizing operation. On this basis, a two-stage high-power pulse generator based on PFN-LT is developed. The following technical parameters of the generator were achieved on a 12 Ω high-power solid resistor: output voltage amplitude of ∼250 kV and output power of ∼5.2 GW at a repetition rate of 5 Hz.

This paper introduces a newly developed EDM pulse generator whose high open voltage for discharge is generated by induced electromotive force using a power supply of only 5 V. The pulse generator can generate short duration and high discharge current pulses. The rising time of discharge current pulses to 5 A can be made shorter than 50 ns with a pulse duration of 200 ns or shorter. The results proved that such discharge current pulse shapes increase material removal volume per discharge and that the higher boosting open voltage facilitates the machining of high resistivity materials.

This article presents the generation scheme of picosecond (ps) pulses based on both step recovery diode (SRD) topology and nonlinear transmission line (NLTL) scheme with a focus on simultaneous rise and fall time compression. First, the SRD topology is suggested and investigated for manifesting the capability of pulse compression. The SRD solution is then integrated with different NLTL schemes for alienating and achieving rise or fall time compression in the ps regime. It is observed that single NLTL integration only sharpens the rising or falling edge at the same time. To overcome this challenge, two NLTLs having different diode polarities are then integrated with SRD topology-based ps pulse generator to compress rise and fall time simultaneously. The theory of NLTL is developed in each case, and based on it, the shortest rise and fall time is selected for the final design. Several parameters that are responsible for waveform distortion are also investigated in detail as well. Finally, we have fabricated four different pulse generators in which the first three only compress the rise time whereas the fourth one is responsible for both rise and fall time compressions. The overall pulse duration for the first three generators falls within 80–95 ps having different ringing levels and they are based on rise time compression only. The pulse duration for the fourth pulse generator is almost 25 ps having a detailed ringing level of −14.24 dB and full-width at half-maximum (FWHM) of 10.1 ps based on both rise and fall time compressions. Finally, all these pulse generators are compared with the state of the arts in the literature where they utilize different techniques for sharpening and the superiority of our proposed designs is provided. These generators will find their key role and will be the best candidates for ultra-wide band (UWB) radars for electromagnetic imaging and sensing applications, ultrafast electronic techniques including edge sharpening, future oscilloscopes, comb, or pulse generators, and geophysical exploration.

The ability to reduce the rise time of a voltage pulse formed by a high-voltage pulse generator in a gyromagnetic line due to the excitation of a gyromagnetic precession of the magnetization vector of a saturated ferrite is demonstrated. At a load of 50 Ω, voltage pulses with a rise time of 135–140 ps, an amplitude of 170 kV, and a pulse repetition frequency of 300 Hz were obtained. The generator circuit is described and the results of experiments are presented.

This paper proposes an ultra-wideband (UWB) pulse generator featuring high output amplitude for applications with long transmission and detection range. The output signal of a switch-mode power amplifier stage is passively amplified by a wideband matching network to produce output voltage amplitudes beyond the supply voltage level. Incorporating the parallel LC load of the power amplifier into the matching network and considering the constraints of the wideband matching when the power amplifier is ON and OFF, only a 2-section matching network is added for wideband matching. Employing a trapezoidal waveform as the input signal of the power amplifier, the design flexibility of the matching network to generate a regulation-compliant UWB pulse is further extended. Implemented in a 1-V 65-nm CMOS process, the proposed UWB pulse generator produces a UWB pulse with a de-embedded peak-to-peak amplitude ( $V_{pp}$ ) of 2.49 V, a bandwidth of 6.8 GHz and pulse duration of 0.5 ns achieving 249% peak-to-peak to supply voltage ratio.

Research on the effect of pulsed electric field in cell electroporation attracts more attention, especially tumor ablation. This puts forward higher requirements for pulsed electric field parameters. The shape of the pulse waveform was also required in different electroporation applications. Based on this, a multilevel pulse generator with series capacitor structure was proposed in this article. Besides, it can also obtain the different shapes of the pulse waveforms by controlling the timing of semiconductor switches. The voltage amplitude, the number of pulses, and the pulsewidth are all adjustable. A ten-level test prototype with 11 switches was built. The structure was simple and was more compact. It can work stably under the simulated small resistance load. Finally, when the dc charging voltage was 1 kV, the system can achieve a maximum output voltage of ±500 V. The number of pulse in one pulse sequence was 1–500. The pulsewidth was adjustable from 1 to $10~\mu \text{s}$ . By controlling the switch’s timing, it can also obtain the multilevel voltage output, exponential waveform voltage output, and composite waveform output combined narrow pulse with wide pulse.

Marx generator is a voltage boosting device for power pulse compression, in which its capacitors are charged in parallel and discharged in series. To get a higher voltage boost ratio, high-voltage silicon stacks have been applied to substitute the isolated inductances in this study. Experiments with two isolation modes in the Marx generator have been carried out. Experimental results reveal that the high-voltage silicon stacks with the parameters of 50 kV/1 kA used in the Marx generator can increase the voltage step-up ratio to 168.6:1, up from 141:1 and 162.9:1 when isolating inductances and silicon-stacks with parameters of 50 kV/3 kA are applied, respectively. Moreover, the silicon stack-isolating-type Marx generator can almost eliminate the pre-pulse existing on the load if the isolated inductances employed. Therefore, it is crucial to choose appropriate high-voltage silicon stacks as the isolating devices in the Marx generator designed in this study.

Treatment of gas and water for environmental applications requires a high-voltage, fast-rising pulse to act on the plasma gas or water treating reactor, but the existing stacked high-voltage pulse generator is arduous to use owing to its large size, high cost, and relatively slow pulse rise time. In this study, we propose a low-cost, small-volume pulsed power modulator that can significantly reduce the cost and volume of the device and shorten the pulse rise time to meet the requirements of gas and water treatment. The proposed pulsed power modulator is based on a discontinuous conduction mode (DCM) flyback converter, and it generates a high-voltage pulse through the resonance of the flyback transformer secondary side inductance and the parallel capacitor. A straightforward spark gap sharpens the generated high-voltage pulse. Finally, a fast-rising, high-voltage pulse with a narrow pulsewidth run on the load is generated. Through PSIM simulation and actual experiments, we validated the feasibility of the proposed pulse generator and obtained 23 kV, 500-Hz pulses with a width of 0.5- $\mu \text{s}$ width and rise time of 5 ns in actual experiments.

The pulse generator based on drift step recovery diode(DSRD) has broad development prospects in the research of high pulse repetition frequency(PRF), high power pulse generators. In this letter, a pulse generator based on DSRD is successfully developed. The design of circuit topology and design principles are presented. The pulse generator can work stably outputting almost 30kV peak voltage at 100 kHz PRF or 140kV at 25kHz with a 50k $\Omega $ load. What’s more, the influences of power supply voltage and load resistance are studied experimentally.

Currently, in high-frequency electroporation, much progress has been made but limited to research groups with custom-made laboratory prototype electroporators. According to the review of electroporators and economic evaluations, there is still an area of pulse parameters that needs to be investigated. The development of an asymmetric bipolar pulse generator with a maximum voltage of 4 kV and minimum duration time of a few hundred nanoseconds, would enable in vivo evaluation of biological effects of high-frequency electroporation pulses. Herein, from a series of most commonly used drivers and optical isolations in high-voltage pulse generators the one with optimal characteristics was used. In addition, the circuit topology of the developed device is described in detail. The developed device is able to generate 4 kV pulses, with theoretical 131 A maximal current and 200 ns minimal pulse duration, the maximal pulse repetition rate is 2 MHz and the burst maximal repetition rate is 1 MHz. The device was tested in vivo. The effectiveness of electrochemotherapy of high-frequency electroporation pulses is compared to “classical” electrochemotherapy pulses. In vivo electrochemotherapy with high-frequency electroporation pulses was at least as effective as with “classical” well-established electric pulses, resulting in 86% and 50% complete responses, respectively. In contrast to previous reports, however, muscle contractions were comparable between the two protocols.

High-voltage (HV) pulses are widely used in many applications. This study proposes a new HV unipolar pulse generator based on Single-Ended Primary-Inductance Converter (SEPIC) for electroporation applications. The converter in the proposed pulse generator operates in discontinuous conduction mode with continuous input current. The proposed structure uses voltage-boosting modules that are fed from a relatively low voltage DC source with a reduced number of semiconductors. The number of semiconductor devices and the voltage stress across them are important issues for HV pulse generators. The proposed approach does not have any chopping switches at the output stage, which greatly affects cost, efficiency, and system control. The employed semiconductor switches and diodes in the proposed topology have low voltage and current stresses, so the structure can be implemented with the market-available semiconductor technology. Mathematical analysis is presented along with a full design of the system components. Finally, simulation and experimental results are presented to validate the proposed concept.

A triggered vacuum switch (TVS) has been applied in high pulsed power systems. It is operated by using the plasma sequentially generated at a trigger device and a main electrode. Firstly, the initial plasma is ignited at the trigger device by surface flashover mechanism. Then, the main plasma, which is induced by the initial plasma, is generated at the main electrode. In general, the research on the characteristics of trigger jitter, main jitter, and delay is essential to develop a highperformance TVS. These characteristics are crucially affected by the trigger device. Accordingly, we have fabricated a trigger device with a ring electrode and measured the trigger jitter, main jitter and delay at voltage up to 20 kV. The measured values of delay are 4.3–9.6 µs, of the trigger jitter are 0.56–2.1 µs, and of the main jitter are 3.1–5.0 µs. As a next step, we plan to continue research of characteristics with a new trigger pulse generator having a rise time of hundreds of nanoseconds.

Water treatment is one of the most important issues for all walks of life around the world. Different from the conventional water treatment technology, the advanced power electronic pulse technology has unique features and advantages for the modern water treatment. Unfortunately, there is no literature reported to describe them in a comprehensive and systematic way. To fill this gap, an overview of modern power electronic pulse generators (PPGs) for water treatment is presented. This article, for the first time, classifies the different types of PPGs from the viewpoint of pulse formation. Each of them is discussed, and the advantages and disadvantages are compared and summarized. Aside from that, this article presents the development and trend of the pulse generators suitable for the specified water treatment processes such as electrolysis, sterilization, and discharge degradation. Finally, a list of more than 100 relevant technical papers is also appended for a quick reference.

In recent years, semiconductor switches have gradually replaced traditional gas switches due to their long lifetime and smaller volume. However, the rated current of the semiconductor switches limits the applications of the all-solid-state pulsed power generators. Usually, multiple semiconductor switches or pulse generators are required in parallel to share a large current in the case of the enormous power applications. In this article, a new high-current all-solid-state pulsed power generator based on Marx generators connected in parallel was proposed. One group of semiconductor switches was used to control the charging of the Marx generators. The driving circuits can be simplified due to fewer switches. It can also improve the discharge frequency and the output voltage over a capacitive load. Six 4-stage Marx generators connected in parallel have been employed to verify the proposed topologies on a capacitive and a resistive load. From the experimental results, with 1.2 kV, 150 A, and 2.4 kV, 50 A, pulses have been got on an 8- $\Omega $ resistive load and a 440-pF capacitive load, respectively. The balanced output currents can reduce the output voltage overshoot and make the system more stable and reliable.

Square wave pulses have been identified as more lethal compared to exponential decay pulses in PEF applications. This is because of the on-time which is longer causes a formidable impact on the microorganisms in the food media. To have a reliable high-voltage pulse generator, a technique of capacitor discharge was employed. Four units of capacitor rated 100 μF 1.2 kV were connected in series to produce 25 μF 4.8 kV which were used to store the energy of approximately 200 J. The energy stored was discharged via HTS 181-01-C to the load in the range of nano to microseconds of pulse duration. The maximum voltage applied was limited to 4 kV because it is a lab-scale project. The electrical circuit diagram and the development procedure, as well as experimental results, are presented.

A power and area-efficient pulse-amplitude modulation 4 (PAM-4) transmitter using 3-tap feed-forward equalizer (FFE) based on a slow-wave transmission line is presented. Passive delay line is adopted for generating equalizer tap to overcome the high clocking power consumption. The transmission line achieves high slow-wave factor of 15 with double floating metal shields around the differential coplanar waveguide. The physical dimensions of the transmission line are determined to have low loss and a high slow-wave factor with a small chip area by optimization with 3-D electromagnetic simulations. The transmitter includes 4:1 multiplexers (MUXs) and a quadrature clock generator for high-speed data generation in a quarter-rate system. The 4:1 MUX utilizes 2-UI pulse generator and the input configuration is determined by qualitative analysis. The chip is fabricated in 65-nm CMOS technology and occupies area of 0.151 mm2. The proposed transmitter system exhibits the energy efficiency of 3.03 pJ/b at the data rate of 48 Gb/s with PAM-4 signaling.

This study presents a robust design of a trigger pulse generator that produces trigger pulses of variable widths/durations that are tuned using an external control as per the requirements. The proposed design comprises two elementary modules: a delay element and an XOR circuit. The proposed circuit is implemented using a 16 nm CMOS technology node and simulation results have been verified using the SPICE simulator. Various performance parameters such as power consumption, power delay-product, energy-delay product and impact of key circuit parameters [supply voltage (V DD), channel length (Lg), gate width (Wg), channel doping concentration (N A), oxide thickness (T OX), threshold voltage (V T) and carrier mobility (µ o)] on the duration of trigger pulses have been studied in-depth and performance parameters are compared with circuits already available in the literature. The proposed circuit produces trigger pulses of a minimum width of 191.3 ps at a nominal supply of 1.0 V with an average power consumption of 160 nW. The width of the trigger pulses can be varied from 191.3 to 457.2 ps using an external control from 1.0 to 0.7 V, respectively, at 16 nm technology node.