27 citations · 79 across the 11 of their papers we have counts for
11 papers
Super-exponential Amplification of Wavepacket Propagation in Traveling Wave Tubes
Kasra Rouhi, Filippo Capolino, Alexander Figotin
We analyze wavepacket propagation in traveling wave tubes (TWTs) analytically and numerically. TWT design in essence comprises a pencil-like electron beam in vacuum interacting wit…
Small-Signal Model for Inhomogeneous Helix Traveling-Wave Tubes using Transfer Matrices
Robert Marosi, Kasra Rouhi, Tarek Mealy +2
Abstract We introduce a practical method for modeling the small-signal behavior of frequency-dispersive and inhomogeneous helix-type traveling-wave tube (TWT) amplifiers based on a…
Chiral terahertz lasing with Berry curvature dipoles
Amin Hakimi, Kasra Rouhi, Tatiana G. Rappoport +2
Materials with Berry curvature dipoles (BDs) support a non-Hermitian electro-optic (EO) effect that is investigated here for lasing at terahertz (THz) frequencies. Such a system is…
Simple Reciprocal Electric Circuit Exhibiting Exceptional Point of Degeneracy
Kasra Rouhi, Filippo Capolino, Alexander Figotin
An exceptional point of degeneracy (EPD) occurs when both the eigenvalues and the corresponding eigenvectors of a square matrix coincide and the matrix has a nontrivial Jordan bloc…
Parametric Modeling of Serpentine Waveguide Traveling Wave Tubes
Kasra Rouhi, Robert Marosi, Tarek Mealy +2
A simple and fast model for numerically calculating small-signal gain in serpentine waveguide traveling-wave tubes (TWTs) is described. In the framework of the Pierce model, we con…
Time Modulation to Manage and Increase the Power Harvested From External Vibrations
Alireza Nikzamir, Kasra Rouhi, Alexander Figotin +1
We investigate how a single resonator with a time-modulated component extracts power from an external ambient source. However, the collected power is largely dependent on the preci…
Analytical Solution for Space-Charge Waves in a Two-Stream Cylindrical Electron Beam
Tarek Mealy, Robert Marosi, Kasra Rouhi +1
We present an analytical method to compute the wavenumbers and electric fields of the space-charge-wave eigenmodes supported by a two-stream electron beam, consisting of a solid in…
Enhanced Sensitivity of Degenerate System Made of Two Unstable Resonators Coupled by Gyrator Operating at an Exceptional Point
Kasra Rouhi, Alireza Nikzamir, Alexander Figotin +1
We demonstrate that a circuit comprising two unstable LC resonators coupled via a gyrator supports an exceptional point of degeneracy (EPD) with purely real eigenfrequency. Each of…
Exceptional Points in Gyrator-Based Circuit and Nonlinear High-Sensitivity Oscillator
Alireza Nikzamir, Kasra Rouhi, Alexander Figotin +1
We present a scheme for high-sensitive oscillators based on an exceptional point of degeneracy (EPD) in a circuit made of two LC resonators coupled by a gyrator. The frequency of o…
Exceptional Degeneracies in Traveling Wave Tubes with Dispersive Slow-Wave Structure Including Space-Charge Effect
Kasra Rouhi, Robert Marosi, Tarek Mealy +3
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 interactiv…
Exceptional Points of Degeneracy Directly Induced by Space-Time Modulation of a Single Transmission Line
Kasra Rouhi, Hamidreza Kazemi, Alexander Figotin +1
We demonstrate how exceptional points of degeneracy (EPDs) are induced in a single transmission line (TL) directly by applying periodic space-time modulation to the per-unit-length…