فهرست مقالات Phase shift

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  1 - Butterfly-like phase shift: a novel gauge for critical coupling of add–drop resonator
  Mahdi Bahadoran Preecha Yupapin
  10.1007/s40094-018-0291-2
  AbstractOptical transfer function for add–drop resonator is derived in the presence of coupling loss using the scattering matrix method. A critical coupling condition for ADR is calculated. The response of the ADR under variation of coupling losses and coupling coeffici چکیده کامل

  AbstractOptical transfer function for add–drop resonator is derived in the presence of coupling loss using the scattering matrix method. A critical coupling condition for ADR is calculated. The response of the ADR under variation of coupling losses and coupling coefficients is studied. The number of allowed states under the critical condition is determined. The full width at half maximum as sharp as 0.17 nm is achieved. It is found that the relative phase shifts of through and drop ports show the same responses under the critical coupling condition. This response emerges in a butterfly-like phase shift, which can be considered as a new evaluating factor for checking the system in critical coupling condition. پرونده مقاله
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  2 - تحلیل و مدلسازی ترانسفورماتورهای شیفت‌دهنده‌ی فاز کلاس Aو D و E باهدف بهبودکیفیت‌توان و حدودپایداری
  هانی شاهنظری ثانی هادی شاهنظری ثانی
  ترانسفورماتور های شیفت دهنده ی فاز با تغییر در دامنه و زاویه ی فاز ولتاژ به منظور کنترل توان انتقال یافته از خطوط مورد استفاده قرار می‌گیرند. در انواع PST در گروه نخست از سوییچ های مکانیکی و قطعات متحرک استفاده می‌شود و در گروه دوم سوییچ های نیمه هادی و مبدل های الکترون چکیده کامل

  ترانسفورماتور های شیفت دهنده ی فاز با تغییر در دامنه و زاویه ی فاز ولتاژ به منظور کنترل توان انتقال یافته از خطوط مورد استفاده قرار می‌گیرند. در انواع PST در گروه نخست از سوییچ های مکانیکی و قطعات متحرک استفاده می‌شود و در گروه دوم سوییچ های نیمه هادی و مبدل های الکترونیک قدرت جایگزین سوییچ های مکانیکی شده است. دراین مقاله تحلیل ساختار درونی وعملکرد ترانسفورماتورهای شیفت دهنده ی فاز کلاس Aو D و E بیان گردیده و با استفاده از یک برنامه، توزیع توان در شبکه ی قدرت دردو حالت استفاده از ترانسفورماتور های شیفت دهنده ی فاز و بدون وجود این ترانسفورماتور ها در نرم افزارMATLAB شبیه سازی شده و نتایج عددی تاثیر ترانسفورماتور های شیفت دهنده ی فاز برروی جریان و توان توزیع شده بین دوخط موازی 110KVبررسی می شود. و مشخص میگردد که ترانسفورماتور های شیفت دهنده ی فاز برای کنترل توزیع توان اکتیو بین خطوط مورد استفاده قرار می گیرند و درترانسفورماتور شیفت دهنده ی فاز کلاس A حدود بالایی و پایینی زاویه ی آتش تریستورها تابعی از شرایط کار سیستم قدرت است و محدودیت تعیین کننده ی عملکرد این ترانسفورماتورها ، بالا بودن محتوای هارمونیکی ولتاژ خروجی است. و درکلاس D ازسوییچ های GTO استفاده شده و خاموش و روشن شدن آن ها به روش کموتاسیون اجباری بوده و یکی از خصوصیات برجسته آن ها عدم وابستگی عملکرد مبدل ها به شرایط کار سیستم است که خروجی آن ها به طور پیوسته و درهر شرایطی قابل کنترل است. پرونده مقاله
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  3 - Dynamic Characteristics and Vibrational Response of a Capacitive Micro-Phase Shifter
  M Fathalilou M Sadeghi S Afrang G Rezazadeh
  The objective of this paper is to control the phase shifting by applying a bias DC voltage and changing the mechanical characteristics in electrostatically-actuated micro-beams. This problem can be more useful in the design of micro-phase shifters, which has not general چکیده کامل

  The objective of this paper is to control the phase shifting by applying a bias DC voltage and changing the mechanical characteristics in electrostatically-actuated micro-beams. This problem can be more useful in the design of micro-phase shifters, which has not generally been investigated their mechanical behavior. By presenting a mathematical modeling, Galerkin-based step by step linearization method (SSLM) and Galerkin-based reduced order model have been used to solve the governing static and dynamic equations, respectively. The equilibrium positions or fixed pints of the system have been determined and the calculated static and dynamic pull-in parameters have been validated by previous experimental and theoretical results and a good agreement has been achieved. The frequency response of the system has been studied and illustrated that changing applied bias DC voltage affects the resonance frequency and maximum amplitude of the system vibrations. Then, phase diagram of the system for various damping ratio and excitation frequencies has been gained. It has been shown that by changing the bias DC voltage applied on the electrostatically-actuated micro-beam, which can be used as a varactor in phase shifter circuit, the stiffness of the micro-beam changes and consequently the phase shifting can be controlled. Finally, effect of the geometrical and mechanical properties of the micro-beam on the value of the phase shifting has been studied. پرونده مقاله
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  4 - Effects of the Residual Stress and Bias Voltage on the Phase Diagram and Frequency Response of a Capacitive Micro-Structure
  S Ahouighazvin M Mohamadifar P Mahmoudi
  In this paper, static and dynamic behavior of a varactor of a micro-phase shifter under DC, step DC and AC voltages and effects of the residual stress on the phase diagram have been studied. By presenting a mathematical modeling, Galerkin-based step by step linearizatio چکیده کامل

  In this paper, static and dynamic behavior of a varactor of a micro-phase shifter under DC, step DC and AC voltages and effects of the residual stress on the phase diagram have been studied. By presenting a mathematical modeling, Galerkin-based step by step linearization method (SSLM) and Galerkin-based reduced order model have been used to solve the governing static and dynamic equations, respectively. The calculated static and dynamic pull-in voltages have been validated by previous experimental and theoretical results and a good agreement has been achieved. Then the frequency response and phase diagram of the system have been studied. It has been shown that increasing the bias voltage shifts down the phase diagram and left the frequency response. Also increasing the damping ratio shifts up the phase diagram. Finally, the effect of residual stress on the phase diagram has been studied. پرونده مقاله
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  5 - A Linear Discriminant Analysis based Modulation Recognition Method for Linear Modulations
  Mohamad Reza Ahvaraki Seyed Ali Ghroashi Behrad Mahboobi
  In this paper, a new method for signal modulation classification based on Linear Discriminant Analysis for multi-class cases is introduced and its results are compared with two other methods of automatic modulation classification. Higher-order complex cumulants are used چکیده کامل

  In this paper, a new method for signal modulation classification based on Linear Discriminant Analysis for multi-class cases is introduced and its results are compared with two other methods of automatic modulation classification. Higher-order complex cumulants are used as feature vectors in the first place. Then, linear Fisher discriminant analysis maps these vectors to another space to separate different classes efficiently. One versus all support vector machine classifier and kernel Fisher discriminant analysis methods with radial basis function kernel is used. The achieved results in comparison with two research papers show that the proposed method classifies the classes in a shorter time with equal or better accuracy. پرونده مقاله