202 citations · 1.3k across the 26 of their papers we have counts for
30 papers
Nonreciprocal Polychromatic Radiation from a Space-Time-Modulated Omega-Topology Meta-Transceiver
Sajjad Taravati, Ya-Adama Kabia
Time-modulated metasurfaces offer a magnet-free route to nonreciprocal wave control, but existing realizations modulate only the electric response of the structure, and proposals f…
Temporal Quadrupole Moments: Floquet Higher-Order Topology with Nonreciprocal Frequency-Converting Corner States
Sajjad Taravati, Jingbang Liu
We introduce the temporal quadrupole moment and leverage its nonreciprocal frequency-converting topological corner states to experimentally realize a magnet-free transceiving circu…
The Bragg Frequency Convertor: A Meeting Between Spatial and Temporal Periodicities For Selective Parametric Frequency Translation
Sajjad Taravati
This study introduces the Bragg Frequency Converter, a spatiotemporal-periodic grating concept that extends conventional Bragg gratings into the dynamic domain for pure parametric…
Frequency Conversion Characteristics of Spatiotemporal Josephson Metasurfaces for Quantum Applications
Sajjad Taravati
This presentation explores the various characteristics of a nonreciprocal, frequency-converting Josephson metasurface operating at millikelvin temperatures. Leveraging the unique p…
Temporal Bragg Gratings: Broadband Reconfigurable Parametric Amplifiers
Sajjad Taravati
This paper introduces temporal Bragg gratings as a new class of broadband, reconfigurable parametric amplifiers. We present a comprehensive investigation of power amplification in…
On-Chip Nonreciprocal Superconducting Frequency Multiplier for Cryogenic Millimeter-Wave Multiplexed Control
Sajjad Taravati
Space-time-periodic modulation of superconducting circuits offers a compact, on-chip route to nonreciprocity, frequency conversion, and parametric gain, without the bulk of convent…
Designing Space-Time Metamaterials: The Central Role of Dispersion Engineering
Sajjad Taravati
Space-time metamaterials are redefining wave engineering by enabling fully dynamic four-dimensional control of electromagnetic fields, allowing simultaneous manipulation of frequen…
Space-Time-Coupled Qubits for Enhanced Superconducting Quantum Computing
Sajjad Taravati
The pursuit of scalable and robust quantum computing necessitates innovative approaches to overcome the inherent challenges of qubit connectivity, decoherence, and susceptibility t…
Light Interaction With a Space-Time-Modulated Josephson Junction Array and Application to Angular-Frequency Beam Multiplexing
Sajjad Taravati
Josephson junctions, as pivotal components of modern technologies such as superconducting quantum computing, owe their prominence to their unique nonlinear properties at low temper…
Finite-Difference Time-Domain Simulation of Wave Transmission Through Space-Time-Varying Media
Sajjad Taravati, Ahmed A Kishk, George V Eleftheriades
A comprehensive study on the Finite Difference Time Domain (FDTD) numerical modelling of space- and time-varying media is presented. We investigate the dynamic behavior of oblique…
Photon-Blockade Analogue Nonreciprocal Absorption in Spatiotemporal Metasurfaces
Sajjad Taravati
Controlling the flow of electromagnetic energy is essential for advancing quantum technologies. We introduce a spatiotemporally modulated superconducting metasurface that exhibits…
Magnet-Free Nonreciprocal Phase-Shifter Based on Time Modulation
Sajjad Taravati, George V. Eleftheriades
Recently, nonreciprocal phase shifters have attracted a surge of interest thanks to the advent of nonreciprocal electromagnetic systems, such as nonreciprocal metasurfaces, nonreci…
Lightweight Low-Noise Linear Isolator Integrating Phase-Engineered Temporal Loops
Sajjad Taravati, George V. Eleftheriades
The quest for efficient and versatile microwave and optical isolators has recently spawned several novel space-time-modulated isolator structures. However, such space-time isolator…
Highly Linear Nonmagnetic Circulator Enabled By A Temporal Nonreciprocal Phase Shifter
Sajjad Taravati, George V. Eleftheriades
Conventional circulators are made of magnetic ferrites and suffer from a cumbersome architecture, incompatibility with integrated circuit technology and inability for high frequenc…
Intelligent-Metasurface-Assisted Full-Duplex Wireless Communications
Sajjad Taravati, George V. Eleftheriades
The limited radio-frequency spectrum is a fundamental factor in the design of wireless communication systems. The ever increasing number of wireless devices and systems has led to…
Pure and Linear Frequency Converter Temporal Metasurface
Sajjad Taravati, George V. Eleftheriades
Metasurfaces are ultrathin structures which are constituted by an array of subwavelength scatterers with designable scattering responses. They have opened up unprecedented exciting…
Full-duplex Reflective Beamsteering Metasurface Featuring Magnetless Nonreciprocal Amplification
Sajjad Taravati, George V. Eleftheriades
Nonreciprocal radiation refers to electromagnetic wave radiation in which a structure provides different responses under the change of the direction of the incident field. Modern w…
Programmable Nonreciprocal Metaprism
Sajjad Taravati, George V. Eleftheriades
Optical prisms are made of glass and map temporal frequencies into spatial frequencies by decomposing incident white light into its constituent colors and refract them into differe…
Four-Dimensional Wave Transformations By Space-Time Metasurfaces
Sajjad Taravati, George V. Eleftheriades
Static metasurfaces have shown to be prominent compact structures for reciprocal and frequency-invariant transformation of electromagnetic waves in space. However, incorporating te…
Nonreciprocal-Beam Phased-Array Antennas
Reza Karimian, Shahrokh Ahmadi, Mona Zaghloul +1
This study presents a nonreciprocal-beam phased-array antenna constituted of phase-gradient patch radiators integrated with transistor-based nonreciprocal phase shifters. Such an a…
Space-Time Medium Functions as a Perfect Antenna-Mixer-Amplifier Transceiver
Sajjad Taravati, George V. Eleftheriades
We show that a space-time-varying medium can function as a front-end transceiver, i.e., an antenna-mixer-amplifier. Such a unique functionality is endowed by space-time surface wav…
Full-Duplex Nonreciprocal-Beam-Steering Metasurfaces Comprising Time-Modulated Twin Meta-Atoms
Sajjad Taravati, George V. Eleftheriades
We present the concept, theoretical model and experimental implementation of a full-duplex nonreciprocal-beam-steering transmissive phase-gradient metasurface. Such a metasurface i…
Space-Time Modulation: Principles and Applications
Sajjad Taravati, Ahmed A. Kishk
This paper overviews the principles, theoretical analysis and numerical simulation of STM media and their applications in communication systems. We first present a global perspecti…
Generalized Space-Time Periodic Diffraction Gratings: Theory and Applications
Sajjad Taravati, George V. Eleftheriades
This paper studies the theory and applications of the diffraction of electromagnetic waves by space-time periodic (STP) diffraction gratings. We show that, in contrast with convent…