scholarly journals IMPATT Diodes Based on GaAs for Millimeter Wave Applications with Reference to Si

2021 ◽  
Author(s):  
Janmejaya Pradhan ◽  
Satya Ranjan Pattanaik
Keyword(s):  
Power Density ◽  
Output Power ◽  
Millimeter Wave ◽  
Conversion Efficiency ◽  
Small Signal ◽  
Rf Power ◽  
Signal Characteristics ◽  
Maximum Conversion ◽  
Signal Simulation ◽  
Maximum Conversion Efficiency

The small signal characteristics of DDR IMPATTs based on GaAs designed to operate at mm-wave window frequencies such as 94, 140, and 220 GHz are presented in this chapter. Both the DC and Small signal performance of the above-mentioned devices are investigated by using a small signal simulation technique developed by the authors. The efficiency, output power and power density of GaAs IMPATT is higher than that of Si IMPATT. Results show that the DDR IMPATTs based on GaAs are most suitable for generation of RF power with maximum conversion efficiency up to 220 GHz. The noise behavior of GaAs IMPATT yield less noise as compared to Si IMPATT.

scholarly journals Study on Millimeter-Wave Vivaldi Rectenna and Arrays with High Conversion Efficiency

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Guan-Nan Tan ◽  
Xue-Xia Yang ◽  
Huan Mei ◽  
Zhong-Liang Lu
Keyword(s):  
Millimeter Wave ◽  
Conversion Efficiency ◽  
Large Scale ◽  
High Gain ◽  
Dc Voltage ◽  
Dc Power ◽  
Maximum Conversion ◽  
Maximum Conversion Efficiency ◽  
Vivaldi Antenna ◽  
Conversion Efficiencies

A novel Vivaldi rectenna operated at 35 GHz with high millimeter wave to direct current (MMW-to-DC) conversion efficiency is presented and the arrays are investigated. The measured conversion efficiency is 51.6% at 35 GHz and the efficiency higher than 30% is from 33.2 GHz to 36.6 GHz when the input MMW power is 79.4 mW. The receiving Vivaldi antenna loaded with metamaterial units has a high gain of 10.4 dBi at 35 GHz. A SIW- (substrate integrated waveguide-) to-microstrip transition is designed not only to integrate the antenna with the rectifying circuit directly but also to provide the DC bypass for the rectifying circuit. When the power density is 8.7 mW/cm2, the received MMW power of the antenna is 5.6 mW, and the maximum conversion efficiency of the rectenna element is 31.5%. The output DC voltage of the element is nearly the same as that of the parallel array and is about half of the series array. The DC power obtained by the 1 × 2 rectenna arrays is about two times as much as that of the element. The conversion efficiencies of the arrays are very close to that of the element. Large scale arrays could be expended for collecting more DC power.

REVIEW ON PARAMETRIC GENERATION OF TERAHERTZ WAVE: FROM MAXIMUM CONVERSION EFFICIENCY TO NEW ROUTE TO COMPACT AND PORTABLE SOURCES

2011 ◽  
Vol 20 (03) ◽  
pp. 249-270 ◽  
Author(s):  
YUJIE J. DING ◽  
PU ZHAO ◽  
SRINIVASA RAGAM ◽  
DA LI ◽  
IOULIA B. ZOTOVA
Keyword(s):  
Output Power ◽  
Conversion Efficiency ◽  
Laser Cavity ◽  
Terahertz Wave ◽  
Solid State Laser ◽  
Parametric Generation ◽  
Maximum Conversion ◽  
Laser Crystals ◽  
Maximum Conversion Efficiency ◽  
Photon Conversion

We review the recent progress made by our group on power scaling of THz waves and the development of compact and portable THz sources. By reversely stacking GaP plates, we were able to improve the photon conversion efficiency from 25% to 40%, which is the record-high value. As the number of the stacked GaP plates was increased from 4 to 5, the output power was decreased. This is the evidence on back conversion. In order to make our THz source truly compact and portable, we investigated a new route to THz generation by mixing two frequencies generated by a single Nd :YLF solid-state laser. After two Nd :YLF crystals were introduced in the laser cavity, the output power was scaled up to 4.5 μW. Such a configuration exhibits versatile characteristics such as the generation of different THz frequencies by combining two different laser crystals.

scholarly journals Geometry Optimization of Thermoelectric Modules: Deviation of Optimum Power Output and Conversion Efficiency

Entropy ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 1233
Author(s):  
Mario Wolf ◽  
Alexey Rybakov ◽  
Richard Hinterding ◽  
Armin Feldhoff
Keyword(s):  
Conversion Efficiency ◽  
Thermoelectric Materials ◽  
Power Output ◽  
Geometry Optimization ◽  
Electrical Energy ◽  
Material Research ◽  
Full Understanding ◽  
Fem Simulations ◽  
Maximum Conversion ◽  
Maximum Conversion Efficiency

Besides the material research in the field of thermoelectrics, the way from a material to a functional thermoelectric (TE) module comes alongside additional challenges. Thus, comprehension and optimization of the properties and the design of a TE module are important tasks. In this work, different geometry optimization strategies to reach maximum power output or maximum conversion efficiency are applied and the resulting performances of various modules and respective materials are analyzed. A Bi2Te3-based module, a half-Heusler-based module, and an oxide-based module are characterized via FEM simulations. By this, a deviation of optimum power output and optimum conversion efficiency in dependence of the diversity of thermoelectric materials is found. Additionally, for all modules, the respective fluxes of entropy and charge as well as the corresponding fluxes of thermal and electrical energy within the thermolegs are shown. The full understanding and enhancement of the performance of a TE module may be further improved.

Modeling of Near-Field Concentrated Solar Thermophotovoltaic Microsystem

2014 ◽  
Author(s):  
Mahmoud Elzouka ◽  
Mukesh Kulsreshath ◽  
Sidy Ndao
Keyword(s):  
Power Density ◽  
Output Power ◽  
Conversion Efficiency ◽  
Near Field ◽  
Separation Distance ◽  
Heat Radiation ◽  
Cooling Power ◽  
Emitter Temperature ◽  
Pv Cell ◽  
Field Radiation

Modeling of a near-field concentrated solar thermophotovoltaic (STPV) microsystem is carried out to investigate the use of STPV-based solid-state energy conversion as a high power density MEMS power generator. Near-field radiation can be realized between two closely separated surfaces (i.e. order of radiation wavelength), resulting in the enhancement of the heat radiation flux orders of magnitudes higher than the blackbody limit, consequently increasing cell output power density. The Near-field STPV model consists of an absorber/emitter model used to estimate the net power absorbed from solar irradiance, a near-field radiation transfer model to evaluate the power tunneled from the emitter to the PV cell at different separation distances, and a PV cell model to determine the photocurrent generated due to thermal radiation absorbed. Results reveal that decreasing separation distance between the emitter and the PV cell increases the absorber/emitter thermal efficiency, increases conversion efficiency, and the power density (×100 far-field). The results also predict increase in cooling power requirement as the separation distance is decreased, which may be a limiting design parameter for near-field STPV microsystems. Based on the model, an overall conversion efficiency of 17% at a separation distance of 10 nm and emitter temperature of 2000 K with solar concentration 6000 sun can be reached; this corresponds to an output power density of 9×105 W/m2.

Mitsubishi FA-Based Solar Photovoltaic Tracking Control System

2012 ◽  
Vol 468-471 ◽  
pp. 928-932
Author(s):  
De Jun Miao ◽  
Yi Zong Dai
Keyword(s):  
Conversion Efficiency ◽  
Tracking Control ◽  
Control Strategies ◽  
Photovoltaic System ◽  
Solar Photovoltaic ◽  
Input Control ◽  
Maximum Conversion ◽  
Maximum Conversion Efficiency ◽  
Solar Photovoltaic System ◽  
And Control

A sort of two axes auto- tracking solar photovoltaic system based on Mitsubishi FA productions to solve the problem of low conversion efficiency in existing systems. It is discussed that how to design frames of input、control、execution 、functions and control strategies. The method of timing light intensity comparison is proposed to achieve automatic tracking of solar cells. This system can regulate automatically the horizontal angle and the vertical angle of the battery board by controlling circuits of sensors, plc, transducer and amplifier. Sound results are shown by tracking maximum conversion efficiency of this system.

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