Zobrazeno 1 - 10
of 125
pro vyhledávání: '"Abdelshafy, Ahmed A."'
Abstract -- We construct an analytical model for the dispersion of the hot modes in a traveling wave tube (TWT) based on the Lagrangian field theory, upgrading its constants to be frequency-dependent. The frequency dependence of the parameters of the
Externí odkaz:
http://arxiv.org/abs/2201.01712
Autor:
Oshmarin, Dmitry, Abdelshafy, Ahmed F., Nikzamir, Alireza, Green, Michael M., Capolino, Filippo
The first experimental demonstration of an oscillator based on a periodic, resonant microstrip circuit with a degenerate band edge (DBE) is presented. The DBE is a fourth-order exceptional degeneracy of the eigenmodes in a lossless periodic waveguide
Externí odkaz:
http://arxiv.org/abs/2109.07002
We demonstrate that a periodic waveguide comprising of uniform lossless segments together with discrete gain and radiating elements supports exceptional points of degeneracy (EPDs). We provide analytical expressions for all possible conditions that g
Externí odkaz:
http://arxiv.org/abs/2104.04056
The concept of exceptional point of degeneracy (EPD) is used to conceive a degenerate synchronization regime that is able to enhance the level of output power and power conversion efficiency for backward wave oscillators (BWOs) operating at millimete
Externí odkaz:
http://arxiv.org/abs/2104.00113
Autor:
Rouhi, Kasra, Marosi, Robert, Mealy, Tarek, Abdelshafy, Ahmed F., Figotin, Alexander, Capolino, Filippo
The interaction between a linear electron beam and a guided electromagnetic wave is studied in the contest of exceptional points of degeneracy (EPD) supported by such an interactive system. The study focuses on the case of a linear beam traveling wav
Externí odkaz:
http://arxiv.org/abs/2103.14767
Publikováno v:
Phys. Rev. Applied 15, 064021 (2021)
Abstract An exceptional point of degeneracy (EPD) is induced in a system made of an electron beam interacting with an electromagnetic (EM) guided mode. This enables a degenerate synchronous regime in backward wave oscillators (BWOs) where the electro
Externí odkaz:
http://arxiv.org/abs/2005.08912
Autor:
Abdelshafy, Ahmed F., Oshmarin, Dmitry, Othman, Mohamed A. K., Green, Michael M., Capolino, Filippo
We propose a new class of oscillators by engineering the dispersion of two-coupled periodic waveguides to exhibit a degenerate band edge (DBE). The DBE is an exceptional point of degeneracy (EPD) of order four, i.e., representing the coalescence of f
Externí odkaz:
http://arxiv.org/abs/2002.00857
Publikováno v:
Phys. Rev. Applied 14, 014078 (2020)
We show how an exceptional point of degeneracy (EPD) is formed in a system composed of an electron beam interacting with an electromagnetic mode guided in a slow wave structure (SWS) with distributed power extraction from the interaction zone. Based
Externí odkaz:
http://arxiv.org/abs/1904.12946
Autor:
Abdelshafy, Ahmed F., Othman, Mohamed A. K., Oshmarin, Dmitry, Al-Mutawa, Ahmad, Capolino, Filippo
We present a novel paradigm for dispersion engineering in coupled transmission lines (CTLs) based on exceptional points of degeneracy (EPDs). We develop a theory for fourth-order EPDs consisting of four Floquet-Bloch eigenmodes coalescing into one de
Externí odkaz:
http://arxiv.org/abs/1809.05256
Publikováno v:
Phys. Rev. Applied 11, 014007 (2019)
We present a general theory of exceptional points of degeneracy (EPD) in periodically time-variant systems that do not necessarily require the presence of loss or gain, and we show that even a single resonator with a time-periodic component may devel
Externí odkaz:
http://arxiv.org/abs/1804.01075