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.

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 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.

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.

scholarly journals High-Gain Millimeter-Wave Patch Array Antenna for Unmanned Aerial Vehicle Application

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3914
Author(s):  
Kyei Anim ◽  
Jung-Nam Lee ◽  
Young-Bae Jung
Keyword(s):  
Surface Wave ◽  
Millimeter Wave ◽  
Large Scale ◽  
High Gain ◽  
Metal Plate ◽  
Array Antenna ◽  
Wave Radiation ◽  
Wave Band ◽  
Large Patch ◽  
Large Coupling

A high-gain millimeter-wave patch array antenna is presented for unmanned aerial vehicles (UAVs). For the large-scale patch array antenna, microstrip lines and higher-mode surface wave radiations contribute enormously to the antenna loss, especially at the millimeter-wave band. Here, the element of a large patch array antenna is implemented with a substrate integrated waveguide (SIW) cavity-backed patch fed by the aperture-coupled feeding (ACF) structure. However, in this case, a large coupling aperture is used to create strongly bound waves, which maximizes the coupling level between the patch and the feedline. This approach helps to improve antenna gain, but at the same time leads to a significant level of back radiation due to the microstrip feedline and unwanted surface-wave radiation, especially for the large patch arrays. Using the SIW cavity-backed patch and stripline feedline of the ACF in the element design, therefore, provides a solution to this problem. Thus, a full-corporate feed 32 × 32 array antenna achieves realized gain of 30.71–32.8 dBi with radiation efficiency above 52% within the operational band of 25.43–26.91 GHz. The fabricated antenna also retains being lightweight, which is desirable for UAVs, because it has no metal plate at the backside to support the antenna.

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