scholarly journals Primary Design of Extended Interaction Klystron with Multi-Gap Cavity at 225 GHz

Particles ◽  
2018 ◽  
Vol 1 (1) ◽  
pp. 260-266
Author(s):  
Kaichun Zhang ◽  
Ke Chen ◽  
Qian Xu ◽  
Wangju Xu ◽  
Neng Xiong ◽  
...  
Keyword(s):  
Low Voltage ◽  
Maximum Output Power ◽  
Wave Theory ◽  
Maximum Output ◽  
Coupling Coefficients ◽  
Beam Wave ◽  
Beam Loading ◽  
Beam Voltage ◽  
Extended Interaction ◽  
The Stability

The analytical expressions of the beam–wave coupling coefficients and the beam loading conductance for a 2π mode in a multi-gap cavity is proposed as a circuit of the extended interaction klystron (EIK), are derived by space-charge wave theory. The mechanism of the beam–wave synchronization and the coupling in the multi-gap cavity at 225 GHz are studied in detail by calculating the coupling coefficient and the normalized beam loading conductance as a function of gap number, gap dimension, and beam voltage as well as the perveance. The stability of the circuit is analyzed by considering the quality factor of the electron beam. It is found that the stability of the operating 2π mode is more sensitive to the beam voltage and gap number. Based on the theory and analysis, a 5-gap coupled cavity is proposed as a section of EIK’s circuit. A low voltage EIK with a 4-cavity circuit at 225 GHz is designed and is simulated by a particle-in-cell (PIC) code. The EIK can achieve a maximum output power of ~36 W with more than 30 dB gain at 225 GHz.

Study of Cantilever Structures Based on Piezoelectric Materials for Energy Harvesting at Low Frequency of Vibration

2014 ◽  
Vol 976 ◽  
pp. 159-163 ◽  
Author(s):  
Roberto Ambrosio ◽  
Hector Gonzalez ◽  
Mario Moreno ◽  
Alfonso Torres ◽  
Rafael Martinez ◽  
...  
Keyword(s):  
Energy Harvesting ◽  
Output Power ◽  
Lead Zirconate Titanate ◽  
Maximum Output Power ◽  
Low Frequency ◽  
Electrical Contacts ◽  
Piezoelectric Energy Harvesting ◽  
Maximum Output ◽  
Coupling Coefficients ◽  
Piezoelectric Energy

In this work is presented a study of a piezoelectric energy harvesting device used for low power consumption applications operating at relative low frequency. The structure consists of a cantilever beam made by Lead Zirconate Titanate (PZT) layer with two gold electrodes for electrical contacts. The piezoelectric material was selected taking into account its high coupling coefficients. Different structures were analyzed with variations in its dimensions and shape of the cantilever. The devices were designed to operate at the resonance frequency to get maximum electrical power output. The structures were simulated using finite element (FE) software. The analysis of the harvesting devices was performed in order to investigate the influence of the geometric parameters on the output power and the natural frequency. To validate the simulation results, an experiment with a PZT cantilever with brass substrate was carried out. The experimental data was found to be very close to simulation data. The results indicate that large structures, in the order of millimeters, are the ideal for piezoelectric energy harvesting devices providing a maximum output power in the range of mW

scholarly journals A Low-Voltage Multi-Band ZigBee Transceiver

Electronics ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 1474
Author(s):  
Zhiqun Li ◽  
Yan Yao ◽  
Zengqi Wang ◽  
Guoxiao Cheng ◽  
Lei Luo
Keyword(s):  
Frequency Synthesizer ◽  
Low Voltage ◽  
Supply Voltage ◽  
Maximum Output Power ◽  
Cmos Technology ◽  
Maximum Output ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Front End ◽  
Band Pass

This paper presents a low-voltage ZigBee transceiver covering a unique frequency band of 780/868/915/2400 MHz in 180 nm CMOS technology. The design consists of a receiver with a wideband variable-gain front end and a complex band-pass filter (CBPF) based on poles construction, a transmitter employing the two-point direct-modulation structure, a Ʃ-Δ fractional-N frequency synthesizer with two VCOs and some auxiliary circuits. The measured results show that under 1 V supply voltage, the receiver reaches −93.8 dBm and −102 dBm sensitivity for 2.4 GHz and sub-GHz band, respectively, and dissipates only 1.42 mW power. The frequency synthesizer achieves −106.8 dBc/Hz and −116.7 dBc/Hz phase noise at 1 MHz frequency offset along with 4.2 mW and 3.5 mW power consumption for 2.4 GHz and sub-GHz band, respectively. The transmitter features 2.67 dBm and 12.65 dBm maximum output power at the expense of 21.2 mW and 69.5 mW power for 2.4 GHz and sub-GHz band, respectively.

scholarly journals Determination of Generator Steady State Stability Limit for Multimachine System based on Network Losses Concept

2018 ◽  
Vol 164 ◽  
pp. 01041
Author(s):  
Rusilawati ◽  
Irrine Budi Sulistiawati ◽  
Adi Soeprijanto ◽  
Rony Seto Wibowo
Keyword(s):  
Steady State ◽  
Maximum Output Power ◽  
Stability Limit ◽  
Maximum Output ◽  
Calculation Results ◽  
Network Losses ◽  
Power Limit ◽  
The Stability ◽  
Equivalent Load ◽  
Steady State Stability

In the multimachine circumstances, it is difficult to analyze the steady state stability of each generator. In previous research, analysis of the steady state stability limit has been carried out but only look at the stability of the overall system. Therefore, to analyze the stability of each generator, the multimachine system must be changed into a Single Machine to Infinite Bus (SMIB) system by collecting all the loads into one central load in the infinite bus. The method to change from the multimachine system to SMIB system is presented in this paper. The multimachine system is converted into an equivalent impedance (req and xeq) and an equivalent load based on losses concept. After req and xeq is calculated, then by using steady state stability limit concept, the value of the maximum generation of each generator units can be determined. By means of maximum generation is the maximum output power limit that can be generated without causing unstability. ETAP simulation is used to validate the calculation results of the proposed method. The method was applied to units generator in Java Bali system 500 kV.

scholarly journals Low voltage CMOS power amplifier with integrated analog pre-distorter for BLE 4.0 application

2019 ◽  
Vol 14 (2) ◽  
pp. 895 ◽  
Author(s):  
Selvakumar Mariappan ◽  
Jagadheswaran Rajendran ◽  
Norlaili Mohd Noh ◽  
Harikrishnan Ramiah ◽  
Asrulnizam Abd Manaf ◽  
...  
Keyword(s):  
Power Consumption ◽  
Power Amplifier ◽  
Low Voltage ◽  
Supply Voltage ◽  
Maximum Output Power ◽  
Center Frequency ◽  
Low Power Consumption ◽  
Maximum Output ◽  
Driver Amplifier ◽  
Linear Power Amplifier

<span>In this paper, a low power consumption linear power amplifier (PA) for Bluetooth Low Energy (BLE) application is presented. An analogue pre-distorter (APD) is integrated to the PA. The APD consist of an active inductor, driver amplifier, and a RC phase linearizer. The PA delivers more than 12dB power gain from 2.4GHz to 2.5GHz. At the center frequency of 2.45GHz, the gain of the PA is 13dB with PAE of 26.7% and maximum output power of 14dBm. The corresponding OIP3 is 27.6dBm. The supply voltage headroom of this PA is 1.8V. The propose APD serves to be a solution to improve the linearity of the PA with minimum trade-off to the power consumption.</span>

scholarly journals Black Phosphorus Saturable Absorber for Pulse Generation Using Q-switched Teachnique

2018 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Belal Ahmed Hamida ◽  
L A Hussein ◽  
Sheroz Khan ◽  
Mohamed Hadi Habaebi ◽  
Ahmad Anwar Zainuddin ◽  
...  
Keyword(s):  
Saturable Absorber ◽  
Pulse Train ◽  
Ring Cavity ◽  
Maximum Output Power ◽  
Pulse Generation ◽  
Black Phosphorus ◽  
Maximum Output ◽  
Erbium Doped ◽  
The Stability ◽  
Laser Ring

This paper reported a passive Q-switched erbium doped fiber laser (EDFL) using two-dimensional (2D) material of black phosphorus saturable absorber (BP-SA). The maximum output power reached is 3.54 mW, which is generated by pump power of 42.327 mW. The results show that a stable pulse was generated with repetition rate starts at about 9.606 kHz and ends at about 44.72 kHz and very narrow pulse width between 40.01 µs and 9.84 µs and pulse energy 80 nJ. Clearly, the stability of the Q-switched pulse train was achieved because the BP-SA film was inserted in the laser ring cavity.

SEM at Low Beam Voltage

1984 ◽  
Vol 42 ◽  
pp. 440-443
Author(s):  
James Pawley
Keyword(s):  
Low Voltage ◽  
Probe Diameter ◽  
Small Probe ◽  
Beam Voltage ◽  
Practical Constraints

Operation of the SEM with V0 = l-3kV (LVSEM) was early recognized to reduce charging artefacts and increase topographic contrast. This early promise was not pursued because several theoretical and practical considerations made it difficult to produce a small probe diameter (d0) at low voltage. Recently, the necessity of using low V0 to image uncoated semiconductors without damaging them has prompted a re-evaluation of LVSEM. This re-evaluation has taken the form of efforts to eliminate the practical constraints and to alleviate the theoretical ones. In the process, some heretofore neglected theoretical advantages of LVSEM have emerged. These problems and possibilities will now be discussed in more detail.

Characterization of microwave-sintered ceramic composites

1993 ◽  
Vol 51 ◽  
pp. 1136-1137
Author(s):  
X. Zhang ◽  
Y. Pan ◽  
T.T. Meek
Keyword(s):  
Matrix Material ◽  
Maximum Output Power ◽  
Ceramic Matrix Composite ◽  
Ceramic Composites ◽  
Processing Technique ◽  
Structure Characterization ◽  
Alumina Powder ◽  
Maximum Output ◽  
Sintered Ceramic

Industrial microwave heating technology has emerged as a new ceramic processing technique. The unique advantages of fast sintering, high density, and improved materials properties makes it superior in certain respects to other processing methods. This work presents the structure characterization of a microwave sintered ceramic matrix composite.Commercial α-alumina powder A-16 (Alcoa) is chosen as the matrix material, β-silicon carbide whiskers (Third Millennium Technologies, Inc.) are used as the reinforcing element. The green samples consisted of 90 vol% Al2O3 powder and 10 vol% ultrasonically-dispersed SiC whiskers. The powder mixture is blended together, and then uniaxially pressed into a cylindrical pellet under a pressure of 230 MPa, which yields a 52% green density. The sintering experiments are carried out using an industry microwave system (Gober, Model S6F) which generates microwave radiation at 2.45 GHz with a maximum output power of 6 kW. The composites are sintered at two different temperatures (1550°C and 1650°C) with various isothermal processing time intervals ranging from 10 to 20 min.

scholarly journals One-Step Preparation of Biochar Electrodes and Their Applications in Sediment Microbial Electrochemical Systems

Catalysts ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 508
Author(s):  
Kui You ◽  
Zihan Zhou ◽  
Chao Gao ◽  
Qiao Yang
Keyword(s):  
Output Power ◽  
Electrode Materials ◽  
Maximum Output Power ◽  
Composite Cathode ◽  
Maximum Output ◽  
Electrochemical Systems ◽  
Composite Cathodes ◽  
One Step ◽  
Microbial Electrochemical Systems ◽  
Hot Melt

Biochar is a kind of carbon-rich material formed by pyrolysis of biomass at high temperature in the absence or limitation of oxygen. It has abundant pore structure and a large surface area, which could be considered the beneficial characteristics for electrodes of microbial electrochemical systems. In this study, reed was used as the raw material of biochar and six biochar-based electrode materials were obtained by three methods, including one-step biochar cathodes (BC 800 and BC 700), biochar/polyethylene composite cathodes (BP 5:5 and BP 6:4), and biochar/polyaniline/hot-melt adhesive composite cathode (BPP 5:1:4 and BPP 4:1:5). The basic physical properties and electrochemical properties of the self-made biochar electrode materials were characterized. Selected biochar-based electrode materials were used as the cathode of sediment microbial electrochemical reactors. The reactor with pure biochar electrode (BC 800) achieves a maximum output power density of 9.15 ± 0.02 mW/m2, which increases the output power by nearly 80% compared with carbon felt. When using a biochar/polyaniline/hot-melt adhesive (BPP 5:1:4) composite cathode, the output power was increased by 2.33 times. Under the premise of ensuring the molding of the material, the higher the content of biochar, the better the electrochemical performance of the electrodes. The treatment of reed powder before pyrolysis is an important factor for the molding of biochar. The one-step molding biochar cathode had satisfactory performance in sediment microbial electrochemical systems. By exploring the biochar-based electrode, waste biomass could be reused, which is beneficial for the environment.

scholarly journals Novel Heat-Mitigating Chip-on-Probe for Brain Stimulation Behavior Experiments

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7334
Author(s):  
Seongwoog Oh ◽  
Jungsuek Oh
Keyword(s):  
Brain Stimulation ◽  
Heat Sink ◽  
Transmission Loss ◽  
Maximum Output Power ◽  
Circuit Board ◽  
Oxide Semiconductor ◽  
Normal Operation ◽  
Cmos Process ◽  
Maximum Output ◽  
The Brain

This paper proposes a novel design for a chip-on-probe with the aim of overcoming the heat dissipation effect during brain stimulations using modulated microwave signals. The temperature of the stimulus chip during normal operation is generally 40 °C–60 °C, which is sufficient to cause unintended temperature effects during stimulation. This effect is particularly fatal in brain stimulation applications that require repeated stimulation. This paper proposes, for the first time, a topology that vertically separates the stimulus chip generating the stimulus signal and the probe delivering the signal into the brain to suppress the heat transfer while simultaneously minimizing the radio frequency (RF) transmission loss. As the proposed chip-on-probe should be attached to the head of a small animal, an auxiliary board with a heat sink was carefully designed considering the weight that does not affect the behavior experiment. When the transition structures are properly designed, a heat sink can be mounted to maximize the cooling effect, reducing the temperature by more than 13 °C in a simulation when the heat generated by the chip is transferred to the brain, while the transition from the chip to the probe experiences a loss of 1.2 dB. Finally, the effectiveness of the proposed design is demonstrated by fabricating a chip with the 0.28 μm silicon-on-insulator (SOI) complementary metal–oxide–semiconductor (CMOS) process and a probe with a RT6010 printed-circuit board (PCB), showing a temperature reduction of 49.8 °C with a maximum output power of 11 dBm. In the proposed chip-on-probe device, the temperature formed in the area in contact with the brain is measured at 31.1 °C.

scholarly journals Study of the Properties of a Hybrid Piezoelectric and Electromagnetic Energy Harvester for a Civil Engineering Low-Frequency Sloshing Environment

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 391
Author(s):  
Nan Wu ◽  
Yuncheng He ◽  
Jiyang Fu ◽  
Peng Liao
Keyword(s):  
Output Power ◽  
Energy Harvester ◽  
Civil Engineering ◽  
Maximum Output Power ◽  
Low Frequency ◽  
Electromagnetic Energy ◽  
Maximum Output ◽  
Piezoelectric Film ◽  
Hybrid Energy ◽  
Level Height

In this paper a novel hybrid piezoelectric and electromagnetic energy harvester for civil engineering low-frequency sloshing environment is reported. The architecture, fabrication and characterization of the harvester are discussed. The hybrid energy harvester is composed of a permanent magnet, copper coil, and PVDF(polyvinylidene difluoride) piezoelectric film, and the upper U-tube device containing a cylindrical fluid barrier is connected to the foundation support plate by a hinge and spring. The two primary means of energy collection were through the vortex street, which alternately impacted the PVDF piezoelectric film through fluid shedding, and the electromotive force (EMF) induced by changes in the magnetic field position in the conducting coil. Experimentally, the maximum output power of the piezoelectric transformer of the hybrid energy harvester was 2.47 μW (circuit load 270 kΩ; liquid level height 80 mm); and the maximum output power of the electromagnetic generator was 2.72 μW (circuit load 470 kΩ; liquid level height 60 mm). The low-frequency sloshing energy collected by this energy harvester can drive microsensors for civil engineering monitoring.

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