The Modulation Index Optimization of Microwave Photonic Frequency Conversion Using Double-Sideband Suppressed-Carrier and Balance Detection

2015 ◽  
Vol 713-715 ◽  
pp. 475-478
Author(s):  
Wei Jiang ◽  
Qing Gui Tan ◽  
Dong Liang ◽  
Xiao Jun Li ◽  
Zhong Bo Zhu
Keyword(s):  
Theoretical Analysis ◽  
High Power ◽  
Frequency Conversion ◽  
High Harmonic ◽  
Modulation Index ◽  
Harmonic Suppression ◽  
Microwave Photonic ◽  
Mach Zehnder Modulator ◽  
Simulation Results

In this paper, on basis of DPMZM (Dual-Parallel Mach-Zehnder Modulator), an approach for microwave photonic frequency conversion using DSSC(double-sideband suppressed-carrier) and balance detection is demonstrated. DSSC and balance detection were used to realize high harmonic suppression, and achieve frequency conversion signal with high power and high spectrum purity. In addition, theoretical analysis and simulation results show that the optimal modulation index is m1=2, m2=1.81, and the harmonic suppression is greater than 30dB.

scholarly journals Microwave Photonic Frequency Conversion Based on a Wavelength Swept Laser

2020 ◽  
Vol 10 (11) ◽  
pp. 3813
Author(s):  
Youxue Kong ◽  
Yuan Cao ◽  
Lin Wang ◽  
Guangying Wang ◽  
Xinhuan Feng ◽  
...  
Keyword(s):  
Frequency Conversion ◽  
Microwave Signal ◽  
Optical Carrier ◽  
Microwave Photonic ◽  
System A ◽  
Conversion Frequency ◽  
Mach Zehnder Modulator ◽  
Conversion Performance ◽  
5 Ghz

Microwave photonic frequency conversion, with flexible tunability and a simple structure based on a wavelength swept laser (WSL), is proposed and experimentally demonstrated. In the proposed frequency conversion system, a broadband WSL was used to generate a frequency-chirped optical carrier, which was sent to a Mach Zehnder modulator (MZM). A microwave signal, with its frequency to be converted, was applied to the MZM. The modulated signal was then sent to a dispersive device, where the waveform was compressed or expanded depending on the dispersion of the dispersive device. After photodetection, a frequency up-converted or down-converted microwave signal was generated. The tuning of the conversion frequency was achieved by adjusting the chirp rate of the optical carrier from the WSL or the dispersion of the dispersive device. The proposed approach was experimentally demonstrated. A microwave signal, with its frequency at 5 GHz, was up-converted to 5.577 GHz and down-converted to 4.936 GHz. The quality of the frequency converted microwave signal was also evaluated. The conversion performance could be further improved by introducing a WSL with a high duty cycle.

scholarly journals Novel Dual Beam Cascaded Schemes for 346 GHz Harmonic-Enhanced TWTs

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 195
Author(s):  
Ruifeng Zhang ◽  
Qi Wang ◽  
Difu Deng ◽  
Yao Dong ◽  
Fei Xiao ◽  
...  
Keyword(s):  
High Power ◽  
Peak Power ◽  
Low Cost ◽  
High Harmonic ◽  
Harmonic Signal ◽  
Input Power ◽  
Plasma Diagnostic ◽  
Dual Beam ◽  
Thz Sources ◽  
Simulation Results

The applications of terahertz (THz) devices in communication, imaging, and plasma diagnostic are limited by the lack of high-power, miniature, and low-cost THz sources. To develop high-power THz source, the high-harmonic traveling wave tube (HHTWT) is introduced, which is based on the theory that electron beam modulated by electromagnetic (EM) waves can generate high harmonic signals. The principal analysis and simulation results prove that amplifying high harmonic signal is a promising method to realize high-power THz source. For further improvement of power and bandwidth, two novel dual-beam schemes for high-power 346 GHz TWTs are proposed. The first TWT is comprised of two cascaded slow wave structures (SWSs), among which one SWS can generate a THz signal by importing a millimeter-wave signal and the other one can amplify THz signal of interest. The simulation results show that the output power exceeds 400 mW from 340 GHz to 348 GHz when the input power is 200 mW from 85 GHz to 87 GHz. The peak power of 1100 mW is predicted at 346 GHz. The second TWT is implemented by connecting a pre-amplification section to the input port of the HHTWT. The power of 600 mW is achieved from 338 GHz to 350 GHz. The 3-dB bandwidth is 16.5 GHz. In brief, two novel schemes have advantages in peak power and bandwidth, respectively. These two dual-beam integrated schemes, constituted respectively by two TWTs, also feature rugged structure, reliable performance, and low costs, and can be considered as promising high-power THz sources.

Performance Evaluation of Optical Carrier Suppression Radio over Fiber System through Modulation Index Enhancement

2013 ◽  
Vol 756-759 ◽  
pp. 1190-1193 ◽  
Author(s):  
Zhao Xu Liu ◽  
Xiao Gang Chen ◽  
Chao Jiang
Keyword(s):  
System Performance ◽  
Radio Over Fiber ◽  
Modulation Index ◽  
Fiber System ◽  
Optical Carrier ◽  
Optical Carrier Suppression ◽  
Mach Zehnder Modulator ◽  
Simulation Results ◽  
Data Signal ◽  
Radio Over Fiber System

The performance of optical carrier suppression (OCS) radio over fiber (RoF) system is evaluated through tuning the modulation index of Mach-Zehnder modulator, and two different data modulation schemes are considered. The quantitative simulation results validate that there exist an optimum modulation index, and the system performance could be improved if the data signal is modulated on only one of two sidebands.

The Research of Output Voltage Error of Matrix Converter Decreased under Low Switch Frequency

2014 ◽  
Vol 971-973 ◽  
pp. 1194-1197
Author(s):  
Yi Hui Xia ◽  
Xiao Feng Zhang ◽  
Ming Zhong Qiao
Keyword(s):  
Theoretical Analysis ◽  
High Power ◽  
Output Voltage ◽  
Bipolar Transistors ◽  
Matrix Converter ◽  
Input Current ◽  
Insulated Gate Bipolar Transistors ◽  
Pulse Modulation ◽  
Average Value ◽  
Simulation Results

Its switch frequency can’?t be high because of the restrains of insulated gate bipolar transistors (IGBTS) when high power electrical motor driven by matrix converter. This paper mainly discuses about the reason for output voltage error with low switch frequency. And based on the reasons, a method for decreasing output voltage error is proposed, that is to say that referenced input current and output voltage is calculated by using their average value in one sample in the indirect space vector pulse modulation (ISVPWM) when switch frequency is low. Simulation results coincide with theoretical analysis, verifying that the proposed method is feasible and theoretical analysis is right.

scholarly journals Research of Motor Soft Start by High Voltage Motor Drive Inverter

2021 ◽  
Vol 252 ◽  
pp. 02015
Author(s):  
Jing Fang ◽  
Le Zeng ◽  
Qianqian Li
Keyword(s):  
Theoretical Analysis ◽  
Energy Saving ◽  
High Voltage ◽  
High Power ◽  
Control Method ◽  
Motor Drive ◽  
Frequency Range ◽  
Optimal Frequency ◽  
Soft Start ◽  
Simulation Results

The over-current phenomenon of direct starting of high voltage and high power motor is serious bad for the safety of motor. We are usually using motor soft start method when we need to start a motor. There are some motor soft start methods, they can somehow reduce the starting over-current, but they are still having some defects except motor drive inverter. Motor drive inverter can not only realize the purpose of energy saving, but also is an ideal soft start device. We can see a lot of papers about control method research of motor drive inverter, but no paper research on motor soft start by motor drive inverter [1]. This paper focuses on research of motor soft start by motor drive inverter. The optimal frequency range of soft start is obtained through theoretical analysis. The simulation results verify the correctness and feasibility of the theoretical analysis.

Design Technique of High Power Efficiency LLC DC-DC Converters for Photovoltaic Cells

2018 ◽  
Vol 2 (1) ◽  
pp. 30
Author(s):  
Hisatsugu Kato ◽  
Yoichi Ishizuka ◽  
Kohei Ueda ◽  
Shotaro Karasuyama ◽  
Atsushi Ogasahara
Keyword(s):  
High Power ◽  
Power Efficiency ◽  
Photovoltaic Cells ◽  
Input Voltage ◽  
Design Technique ◽  
Load Range ◽  
Voltage Range ◽  
Simulation Results ◽  
Secondary Side ◽  
High Power Efficiency

This paper proposes a design technique of high power efficiency LLC DC-DC Converters for Photovoltaic Cells. The secondary side circuit and transformer fabrication of proposed circuit are optimized for overcoming the disadvantage of limited input voltage range and, realizing high power efficiency over a wide load range of LLC DC-DC converters. The optimized technique is described with theoretically and with simulation results. Some experimental results have been obtained with the prototype circuit designed for the 80 - 400 V input voltage range. The maximum power efficiency is 98 %.

scholarly journals Current-Mode Third-Order Quadrature Oscillator Using CDTAs

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jiun-Wei Horng
Keyword(s):  
Theoretical Analysis ◽  
Phase Difference ◽  
Oscillation Frequency ◽  
Current Mode ◽  
Third Order ◽  
Quadrature Oscillator ◽  
Oscillation Condition ◽  
Transconductance Amplifiers ◽  
Simulation Results ◽  
A Current

This paper describes a current-mode third-order quadrature oscillator based on current differencing transconductance amplifiers (CDTAs). Outputs of two current-mode sinusoids with90°phase difference are available in the quadrature oscillator circuit. The oscillation condition and oscillation frequency are orthogonal controllable. The proposed circuit employs only grounded capacitors and is ideal for integration. Simulation results are included to confirm the theoretical analysis.

scholarly journals BBO-sapphire sandwich structure for frequency conversion of high power lasers

2014 ◽  
Vol 4 (5) ◽  
pp. 1092 ◽  
Author(s):  
Carolin Rothhardt ◽  
Jan Rothhardt ◽  
Arno Klenke ◽  
Thomas Peschel ◽  
Ramona Eberhardt ◽  
...  
Keyword(s):  
High Power ◽  
Sandwich Structure ◽  
Frequency Conversion ◽  
High Power Lasers

New repetitive motion planning scheme with cube end-effector planning precision for redundant robotic manipulators

Robotica ◽  
2021 ◽  
pp. 1-22
Author(s):  
Limin Shen ◽  
Yuanmei Wen
Keyword(s):  
Theoretical Analysis ◽  
Motion Planning ◽  
Robotic Manipulators ◽  
Robotic Manipulator ◽  
Repetitive Motion ◽  
End Effector ◽  
Difference Formula ◽  
Planning Scheme ◽  
Simulation Results ◽  
The Difference

Abstract Repetitive motion planning (RMP) is important in operating redundant robotic manipulators. In this paper, a new RMP scheme that is based on the pseudoinverse formulation is proposed for redundant robotic manipulators. Such a scheme is derived from the discretization of an existing RMP scheme by utilizing the difference formula. Then, theoretical analysis and results are presented to show the characteristic of the proposed RMP scheme. That is, this scheme possesses the characteristic of cube pattern in the end-effector planning precision. The proposed RMP scheme is further extended and studied for redundant robotic manipulators under joint constraint. Based on a four-link robotic manipulator, simulation results substantiate the effectiveness and superiority of the proposed RMP scheme and its extended one.

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