Highly Linear Nonmagnetic Circulator Enabled By A Temporal Nonreciprocal Phase Shifter

Sajjad Taravati; George V. Eleftheriades

Home/Archive/arXiv

arXiv · 2107.09788

Highly Linear Nonmagnetic Circulator Enabled By A Temporal Nonreciprocal Phase Shifter

Sajjad Taravati·George V. Eleftheriades

View original source ↗Read source document ↗Export metadata ↓

Abstract

Conventional circulators are made of magnetic ferrites and suffer from a cumbersome architecture, incompatibility with integrated circuit technology and inability for high frequency applications. To overcome these limitations, here we propose a lightweight low-profile non-magnetic circulator comprising a nonreciprocal time-varying phase shifter. This circulator is composing a nonreciprocal temporal phase shifter and two reciprocal delay-line-based phase shifters. The proposed nonreciprocal temporal phase shifter is based on the generation of time-harmonic signals, enforcing destructive interference for undesired time harmonics and constructive interference for desired time harmonics at different locations of the structure. Such a unique task is accomplished through two phase-engineered temporal loops. The phase and frequency of these two loops are governed by external signals with different phases, imparting an effective electronic angular momentum to the system. We observe large isolation level of greater than 32 dB, a P1dB of +31.7 dBm and IIP3 of +42.4 dBm. Furthermore, this circulator is endowed with a reconfigurable architecture and can be directly embedded in a conventional integrated circuit (IC) technology to realize a class of high power handling and linear IC circulators.

Explore related subjects

physics.app-ph physics.ins-det physics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Sajjad Taravati, George V. Eleftheriades. 2021-06-23. Highly Linear Nonmagnetic Circulator Enabled By A Temporal Nonreciprocal Phase Shifter. https://arxiv.org/abs/2107.09788

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Measuring vacancy-type defect density in monolayer semiconductors

Two-dimensional (2D) materials have attracted wide-spread interest due to their unique and tunable properties. Their optoelectronic, mechanical, and thermal properties are greatly influenced by crystal defects, which are, in turn, used to control these properties. However, experimental quantification of the density of defects, whether deliberately introduced or inherent, is very difficult in these atomically thin materials. Here we show that helium atom micro-diffraction can be used to measure the defect density in ~15x20um monolayer MoS2, a prototypical 2D semiconductor, quickly and easily compared to standard methods. We present a simple analytic model, the lattice gas equation, that captures the relationship between atomic Bragg diffraction intensity and defect density. The model, combined with ab initio scattering calculations, shows that our technique can immediately be applied to a wide range of 2D materials, independent of sample chemistry or structure. Additionally, wafer-scale characterization is immediately possible.

physics.app-ph↗

arXiv2026

Compact Modeling of Oxide-Semiconductor, 2D Material, Carbon Nanotube, and Cryogenic Transistors with Experiment Verification

This paper presents a unified compact model for emerging transistor technologies, including oxide-semiconductor field-effect transistors (OSFETs), 2D material FETs (2DFETs), carbon nanotube FETs (CNFETs), and cryogenic MOSFETs. A unified charge-density formulation is developed to account for quantum confinement, trap charges, and band-tail states in channel charge calculations. A physics-based transport model is introduced to seamlessly capture carrier transport from the long-channel diffusive regime to the short-channel ballistic limit. Scaling models are incorporated to accurately describe 2D electrostatic effects. Cryogenic operation is modeled through the inclusion of band-tail states and temperature-dependent mobility and threshold voltage. The proposed model is validated against experimental data from the fabricated OSFETs with multiple channel lengths and published measurements of 2DFETs, CNFETs, and cryogenic MOSFETs. Excellent agreement is demonstrated across diverse device architectures, operating conditions, and material systems.

physics.app-ph↗

arXiv2026

Multiplexing approaches to thermoradiative signatureless communications

Using mid-infrared emission from semiconductor devices for covert communications remains a relatively unexplored and yet promising opportunity. The phenomenon of negative luminescence allows for a method of signatureless covert communications where the net infrared emission of an emitting optoelectronic device is balanced to be identical to the ambient thermal background. In this work we provide a practical demonstration of covert data transfer over a thermoradiative channel with data rates up to 100 kbps. In addition, we demonstrate several additional multiplexing techniques that make the proposed thermoradiative communications method more secure against interception by achieving zero instantaneous optical emission, while remaining detectable if a sufficiently spatially or spectrally discerning observation is utilised. Finally, we discuss various application scenarios in which the proposed methods can be used to achieve secure signatureless communications.

physics.app-ph↗