scholarly journals Design of a Schottky Metal-Brim Structure to Optimize 180–220 GHz Broadband Frequency Doubler MMIC

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 715
Author(s):  
Luwei Qi ◽  
Jin Meng ◽  
Xiaoyu Liu ◽  
Chengyue Yang ◽  
Jingtao Zhou ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
High Efficiency ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Frequency Doubler ◽  
Monolithic Microwave Integrated Circuit ◽  
Current Voltage ◽  
Electrode Edge ◽  
Terminal Structure ◽  
Broadband Frequency

The present work proposes a 180–225 GHz broadband frequency doubler monolithic microwave integrated circuit (MMIC) based on a novel Schottky barrier diode (SBD) terminal structure denoted as a Schottky metal-brim (SMB). Compared with an MMIC adopting the conventional SBD terminal structure, preliminary measurements show that the maximum output power of the MMIC adopting the SMB structure increases from 0.216 mW at 206 GHz to 0.914 mW at 208 GHz. Analysis of the nonlinear current–voltage and capacitance–voltage characteristics of the two terminal structures based on an extended one-dimensional drift-diffusion model, indicates that the SMB structure provides significantly better conversion efficiency than the conventional SBD structure by eliminating the accumulation of charge and additional current paths near the Schottky electrode edge. It provides a feasible scheme for the optimization of MMIC applications requiring high power and high efficiency.

scholarly journals Study on the Efficiency and Dynamic Characteristics of an Energy Harvester Based on Flexible Structure Galloping

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6548
Author(s):  
Peng Liao ◽  
Jiyang Fu ◽  
Wenyong Ma ◽  
Yuan Cai ◽  
Yuncheng He
Keyword(s):  
Numerical Simulation ◽  
Wind Speed ◽  
Physical Model ◽  
Energy Harvester ◽  
High Efficiency ◽  
Lateral Displacement ◽  
Maximum Output Power ◽  
Flexible Structure ◽  
Maximum Output ◽  
Cfd Numerical Simulation

According to the engineering phenomenon of the galloping of ice-coated transmission lines at certain wind speeds, this paper proposes a novel type of energy harvester based on the galloping of a flexible structure. It uses the tension generated by the galloping structure to cause periodic strain on the piezoelectric cantilever beam, which is highly efficient for converting wind energy into electricity. On this basis, a physical model of fluid–structure interaction is established, and the Reynolds-averaged Navier–Stokes equation and SST K -ω turbulent model based on ANSYS Fluent are used to carry out a two-dimensional steady computational fluid dynamics (CFD) numerical simulation. First, the CFD technology under different grid densities and time steps is verified. CFD numerical simulation technology is used to simulate the physical model of the energy harvester, and the effect of wind speed on the lateral displacement and aerodynamic force of the flexible structure is analyzed. In addition, this paper also carries out a parameterized study on the influence of the harvester’s behavior, through the wind tunnel test, focusing on the voltage and electric power output efficiency. The harvester has a maximum output power of 119.7 μW/mm3 at the optimal resistance value of 200 KΩ at a wind speed of 10 m/s. The research results provide certain guidance for the design of a high-efficiency harvester with a square aerodynamic shape and a flexible bluff body.

scholarly journals Investigation on extreme frequency shift in silica fiber-based high-power Raman fiber laser

2018 ◽  
Vol 6 ◽  
Author(s):  
Jiaxin Song ◽  
Hanshuo Wu ◽  
Jun Ye ◽  
Hanwei Zhang ◽  
Jiangming Xu ◽  
...  
Keyword(s):  
Frequency Shift ◽  
Fiber Laser ◽  
High Power ◽  
High Efficiency ◽  
Maximum Output Power ◽  
Gain Medium ◽  
Maximum Output ◽  
Optical Efficiency ◽  
Central Wavelength ◽  
Raman Fiber Laser

In this paper, we experimentally investigated the extreme frequency shift in high-power Raman fiber laser (RFL). The RFL was developed by using a pair of fiber Bragg gratings with fixed and matched central wavelength (1120 nm) combined with a piece of 31-m-long polarization maintaining (PM) passive fiber adopted as Raman gain medium. The pump source was a homemade high-power, linearly polarized (LP) wavelength-tunable master oscillator power amplifier (MOPA) source with ${\sim}25~\text{nm}$ tunable working range (1055–1080 nm). High-power and high-efficiency RFL with extreme frequency shift between the pump and Stokes light was explored. It is found that frequency shift located within 10.6 THz and 15.2 THz can ensure efficient Raman lasing, where the conversion efficiency is more than 95% of the maximal value, 71.3%. In addition, a maximum output power of 147.1 W was obtained with an optical efficiency of 71.3%, which is the highest power ever reported in LP RFLs to the best of our knowledge.

scholarly journals A Compact and High Efficiency Intracavity Opo Based on Periodically-poled Lithium Niobate

2020 ◽  
Author(s):  
Ke Wang ◽  
Mingyao Gao ◽  
Shuhui Yu ◽  
Jian Ning ◽  
Zhenda Xie ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
High Efficiency ◽  
Continuous Wave ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Periodically Poled ◽  
Periodically Poled Lithium Niobate ◽  
Optical Parametric ◽  
Simulated Temperature ◽  
Output Laser

Abstract We demonstrate a compact, high-efficiency and widely tunable intracavity singly resonant optical parametric oscillator (IC-OPO) based on multichannel periodically-poled lithium niobate (PPLN). The IC-OPO is composed of 808 nm pump laser diode (LD), Nd:YVO4 laser and linear OPO. The continuous-wave (CW) mid-infrared (MIR) output laser is tunable from 2.25 μm to 4.79 μm. The maximum output power exceeds 1.08 W at 3.189 μm at 9.1 W LD pump power and the conversion efficiency is 11.88 %. We also build up a prototype with volume of Wmm3 and its total weight is less than 2 Kg. The measured power stability is 1.3 % Root Meat Square (RMS) for a 3 h duration under simulated high temperature conditions of 40 ℃. RMS is 2.6 % for a 4 h duration when simulated temperature is - 40 ℃.

scholarly journals Development of the range extender for a 48 V electric vehicle

2019 ◽  
Vol 177 (2) ◽  
pp. 113-121
Author(s):  
Marcin NOGA
Keyword(s):  
Electric Vehicle ◽  
Hybrid Electric Vehicle ◽  
High Efficiency ◽  
Combustion Engine ◽  
Maximum Output Power ◽  
Operating Voltage ◽  
Maximum Output ◽  
Nickel Metal ◽  
Nickel Metal Hydride ◽  
Range Extender

The article deals with the concept, development and results of preliminary tests of a range extender for an electric light commercial vehicle Melex with a 48 V electrical system. The purpose of the project is to build a prototype of the range extender powered by an internal combustion engine that will increase the range of the vehicle with electric drive, and at the same time will be characterized by a high efficiency and low exhaust emissions. The developed range extender is a combination of a 163cc single-cylinder combustion engine with a generator joined through a ribbed belt transmission. The 3-phase generator from a heavy-duty vehicle was used. In order to match the output voltage of the generator to the system voltage of the electric vehicle, an external adjustable regulator and a rectifier bridge with an increased operating voltage were used. The range extender was attached to a body of the electric vehicle by means of a welded frame made of thin-walled steel profiles. Initial tests of the developed range extender showed its proper interaction with both the lead-acid battery of the vehicle as well as with the nickel-metal hydride battery (NiMH) adapted to 48 V voltage from a hybrid electric vehicle. A maximum output power exceeding 2 kW was obtained. Maximum value of the overall efficiency of the range extender reaches up to 18.8%, which is a high value considering the small size of the used engine and the type of generator. The directions for further development of the range extender were also revealed in this paper.

scholarly journals Full-Band Oversized Turnstile-Based Waveguide Four-Way Power Divider/Combiner for High-Power Applications

Electronics ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 193
Author(s):  
Juan Cano ◽  
Franco Di Paolo ◽  
Angel Mediavilla ◽  
Paolo Colantonio
Keyword(s):  
High Power ◽  
Rectangular Waveguide ◽  
High Efficiency ◽  
Maximum Output Power ◽  
Variable Number ◽  
Power Divider ◽  
Electrical Performance ◽  
Maximum Output ◽  
Relative Bandwidth ◽  
Full Band

Very high-power and high-efficiency microwave applications require waveguide structures to combine/divide the power from/to a variable number of high-power solid-state devices. In the literature, among the different waveguide configurations, those capable of providing the maximum output power show a limited relative bandwidth. To overcome this limitation, in this paper a full-band (40%) waveguide power divider/combiner specifically designed for high-power applications (up to several kW) is presented. The proposed structure uses an evolved turnstile junction with a standard rectangular waveguide common port, rotated 45°, with respect to its central axis, to divide/combine the signal to/from the four output/input rectangular ports. The inclusion of an oversized central cavity together with circular and rectangular waveguide impedance transformers at the common port allows the achievement of a full-band operation with excellent electrical performance, while maintaining a very simple and compact configuration. Only two layers of metal are required for the physical implementation of this structure in platelet configuration. A prototype has been designed covering the full Ka-band (26.5–40 GHz), showing an excellent measured performance with around 30 dB of return loss, 0.18 dB of insertion loss, and less than 1.5° of phase imbalance.

scholarly journals Comparing Novel MMIC and Hybrid Circuit High Efficiency GaAs Schottky Diode mm-Wave Frequency Doublers

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1718
Author(s):  
J. R. Powell ◽  
Colin Viegas ◽  
Hoshiar Singh Sanghera ◽  
P. G. Huggard ◽  
Byron Alderman
Keyword(s):  
Schottky Diode ◽  
Integrated Circuit ◽  
High Efficiency ◽  
The Novel ◽  
Excellent Performance ◽  
Output Waveguide ◽  
Monolithic Microwave Integrated Circuit ◽  
Frequency Doublers ◽  
Hybrid Circuit ◽  
Good Agreement

A novel Schottky diode frequency doubler in E-band, using biased series-connected diodes in the output waveguide, is reported. The doubler was implemented using a GaAs Schottky Monolithic Microwave Integrated Circuit (MMIC) process with integrated capacitors and beam leads. A comparison is made with a hybrid doubler using a more conventional single-ended configuration with two discrete diodes in a planar transmission line circuit. Both devices exhibit excellent performance over the 67–78 GHz design bandwidth, with the novel MMIC design producing 25 to 55 mW at 12 to 22% power conversion efficiency. Good agreement of measurements with simulations was also found.

scholarly journals Tandem Solar Cells Based on Cu2O and c-Si Subcells in Parallel Configuration: Numerical Simulation

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Mihai Răzvan Mitroi ◽  
Valerică Ninulescu ◽  
Laurenţiu Fara
Keyword(s):  
Numerical Simulation ◽  
Solar Cells ◽  
Solar Cell ◽  
Output Power ◽  
High Efficiency ◽  
Low Cost ◽  
Maximum Output Power ◽  
Model Parameters ◽  
Maximum Output ◽  
Parallel Configuration

A tandem solar cell consisting of a bottom c-Si high-efficiency subcell and a top low-cost Cu2O subcell in parallel configuration is evaluated for the first time by a use of an electrical model. A numerical simulation based on the single-diode model of the solar cell is performed. The numerical method determines both the model parameters and the parameters of the subcells and tandem from the maximization of output power. The simulations indicate a theoretical limit value of the tandem power conversion efficiency of 31.23% at 298 K. The influence of temperature on the maximum output power is analyzed. This tandem configuration allows a great potential for the development of a new generation of low-cost high-efficiency solar cells.

scholarly journals A compact and high efficiency intracavity OPO based on periodically poled lithium niobate

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ke Wang ◽  
Mingyao Gao ◽  
Shuhui Yu ◽  
Jian Ning ◽  
Zhenda Xie ◽  
...  
Keyword(s):  
Lithium Niobate ◽  
High Efficiency ◽  
Continuous Wave ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Periodically Poled ◽  
Periodically Poled Lithium Niobate ◽  
Optical Parametric ◽  
Simulated Temperature ◽  
Output Laser

AbstractWe demonstrate a compact, high efficiency and widely tunable intracavity singly resonant optical parametric oscillator (IC-OPO) based on multichannel periodically poled lithium niobate (PPLN). The IC-OPO is composed of 808 nm pump laser diode (LD), Nd:YVO4 laser and linear OPO. The continuous-wave (CW) mid-infrared (MIR) output laser is tunable from 2.25 to 4.79 μm. The maximum output power exceeds 1.08 W at 3.189 μm at 9.1 W LD pump power and the conversion efficiency is 11.88%. We also build up a prototype with volume of 145 × 85 × 42.5 mm3 and its total weight is less than 2 kg. The measured power stability is 1.3% Root Meat Square (RMS) for a 3 h duration under simulated high temperature conditions of 40 °C. RMS is 2.6% for a 4 h duration when simulated temperature is − 40 °C.

scholarly journals Green Route for Fabrication of Water-Treatable Thermoelectric Generators

2022 ◽  
Vol 2022 ◽  
pp. 1-12
Author(s):  
Shinichi Hata ◽  
Misaki Shiraishi ◽  
Soichiro Yasuda ◽  
Gergely Juhasz ◽  
Yukou Du ◽  
...  
Keyword(s):  
Thermoelectric Power ◽  
Organic Semiconductors ◽  
Thermoelectric Materials ◽  
High Performance ◽  
High Efficiency ◽  
Aqueous Media ◽  
Maximum Output Power ◽  
Maximum Output ◽  
Thermoelectric Generators ◽  
Green Route

Since future energy harvesting technologies require stable supply and high-efficiency energy conversion, there is an increasing demand for high-performance organic thermoelectric generators (TEGs) based on waterproof thermoelectric materials. The poor stability of n-type organic semiconductors in air and water has proved a roadblock in the development of reliable thermoelectric power generators. We developed a simple green route for preparing n-type carbon nanotubes (CNTs) by doping with cationic surfactants and fabricated films of the doped CNTs using only aqueous media. The thermoelectric properties of the CNT films were investigated in detail. The nanotubes doped using a cationic surfactant (cetyltrimethylammonium chloride (CTAC)) retained an n-doped state for at least 28 days when exposed to water and air, indicating higher stability than that for contemporary CNT-based thermoelectric materials. The wrapping of the surfactant molecules around the CNTs is responsible for blocking oxygen and water from attacking the CNT walls, thus, extending the lifetime of the n-doped state of the CNTs. We also fabricated thermoelectric power conversion modules comprising CTAC-doped (n-type) and sodium dodecylbenzenesulfonate- (SDBS-) doped (p-type) CNTs and tested their stabilities in water. The modules retained 80±2.4% of their initial maximum output power (at a temperature difference of 75°C) after being submerged in water for 30 days, even without any sealing fills to prevent device degradation. The remarkable stability of our CNT-based modules can enable the development of reliable soft electronics for underwater applications.

scholarly journals Design and simulate a doherty power amplifier using GaAs technology for telecommunication applications

2019 ◽  
Vol 15 (2) ◽  
pp. 845
Author(s):  
Ehsan Barmala
Keyword(s):  
Output Power ◽  
Power Amplifier ◽  
Power Amplifiers ◽  
High Efficiency ◽  
Maximum Output Power ◽  
Input Power ◽  
Power Divider ◽  
Maximum Efficiency ◽  
Maximum Output ◽  
Doherty Power Amplifier

<span>In this paper, a Doherty power amplifier was designed and simulated at 2.4 GHz central frequency which has high efficiency. A Doherty power amplifier is a way to increase the efficiency in the power amplifiers. OMMIC ED02AH technology and PHEMT transistors, which is made of gallium arsenide, have been used in this simulation. The Doherty power amplifier unique feature is its simple structure which is consisting of two parallel power amplifiers and transmission lines. In order to integrate the circuit, the Doherty power transmission amplifier lines were implemented using an inductor and capacitive components. Also, the Wilkinson power divider is used on the chip input. To improve the efficiency, the auxiliary amplifier dimensions is selected enlarge and the further input power is allocated it by the power divider. A parallel R-C circuit has been used at the input of transistors to improve their stability. Simulation results show that the Doherty power amplifier has 17.2 dB output power gain, 23 dBm maximum output power, and its output power P<sub>1dB</sub> =22.6dBm at compression point -1 dB, also, its maximum efficiency is 55.5%.</span>

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