Nonreciprocal Graphene Devices and Antennas Based on Spatiotemporal Modulation

Correas-Serrano, D.; Gómez‐Díaz, J. S.; Sounas, Dimitrios L.; Hadad, Yakir; Álvarez‐Melcón, A.; Alù, Andrea

doi:10.1109/lawp.2015.2510818

Cited by 117 publications

(92 citation statements)

References 19 publications

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“…In this context, particularly relevant are the recent developments in state-of-the-art graphene-based modulators that demonstrate an intrinsic device modulation frequency of 150 GHz (33), which is about one or two orders of magnitude smaller than the thermal emission frequency at 500-1,500 K--therefore making our proposal realistic also in the thermal infrared frequency range. In this context, our group has recently proposed a theoretical design for a nonreciprocal radiation setup based on a dual-mode waveguide operating at infrared frequencies based on modulated graphene layers (34). More broadly, our results also show that time-varying emitters and antennas may provide a fertile ground for future communication systems.…”

Section: Resultsmentioning

confidence: 52%

Breaking temporal symmetries for emission and absorption

Hadad

Soric

Alù

2016

Proc. Natl. Acad. Sci. U.S.A.

261

177

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Time-reversal symmetries impose stringent constraints on emission and absorption. Antennas, from radiofrequencies to optics, are bound to transmit and receive signals equally well from the same direction, making a directive antenna prone to receive echoes and reflections. Similarly, in thermodynamics Kirchhoff's law dictates that the absorptivity and emissivity are bound to be equal in reciprocal systems at equilibrium, e(ω, θ) = a(ω, θ), with important consequences for thermal management and energy applications. This bound requires that a good absorber emits a portion of the absorbed energy back to the source, limiting its overall efficiency. Recent works have shown that weak time modulation or mechanical motion in suitably designed structures may largely break reciprocity and time-reversal symmetry. Here we show theoretically and experimentally that a spatiotemporally modulated device can be designed to have drastically different emission and absorption properties. The proposed concept may provide significant advances for compact and efficient radiofrequency communication systems, as well as for energy harvesting and thermal management when translated to infrared frequencies.

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Section: Resultsmentioning

confidence: 52%

Breaking temporal symmetries for emission and absorption

Hadad

Soric

Alù

2016

Proc. Natl. Acad. Sci. U.S.A.

261

177

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“…As such, it is an excellent candidate for realization of time-modulated metasurfaces. In [40], spatiotemporal modulation of graphene sheets has been proposed to develop power isolator waveguides and nonreciprocal leaky-wave antennas through space-time modal transitions of SPPs. In [47], the authors have demonstrated theoretical realization of space-time gradient metamaterials based on graphene-wrapped microwires by using a robust semi-analytical framework based on multipole scattering which overcomes the challenges facing time-domain simulation techniques for accurate characterization of time-modulated systems with significantly different time-scales of optical and modulation frequencies.…”

Section: Implementation Based On Graphene-wrapped Microwiresmentioning

confidence: 99%

Electrically tunable harmonics in time-modulated metasurfaces for wavefront engineering

2018

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Modulation of metasurfaces in time gives rise to several exotic space-time scattering phenomena by breaking the reciprocity constraint and generation of higher-order frequency harmonics. We introduce a new design paradigm for time-modulated metasurfaces, enabling tunable engineering of the generated frequency harmonics and their emerging wavefronts by electrically controlling the phase delay in modulation. It is demonstrated that the light acquires a dispersionless phase shift regardless of incident angle and polarization, upon undergoing frequency conversion in a timemodulated metasurface which is linearly proportional to the modulation phase delay and the order of generated frequency harmonic. The conversion efficiency to the frequency harmonics is independent of modulation phase delay and only depends on the modulation depth and resonant characteristics of the metasurface, with the highest efficiency occurring in the vicinity of resonance, and decreasing away from the resonant regime. The modulation-induced phase shift allows for creating tunable spatially varying phase discontinuities with 2π span in the wavefronts of generated frequency harmonics for a wide range of frequencies and incident angles. Specifically, we apply this approach to a time-modulated metasurface in the Teraherz regime consisted of graphene-wrapped silicon microwires. For this purpose, we use an accurate and efficient semi-analytical framework based on multipole scattering. We demonstrate the utility of the design rule for tunable beam steering and focusing of generated frequency harmonics giving rise to several intriguing effects such as spatial decomposition of harmonics, anomalous bending with full coverage of angles and dual-polarity lensing. Furthermore, we investigate the angular and spectral performance of the time-modulated metasurface in manipulation of generated frequency harmonics to verify its constant phase response versus incident wavelength and angle. The nonreciprocal response of the metasurface in wavefront engineering is also studied by establishing nonreciprocal links with large isolations via modulationinduced phase shift. The proposed design approach enables a new class of high-efficiency tunable metasurfaces with wide angular and frequency bandwidth, wavefront engineering capabilities, nonreciprocal response and multi-functionality.

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“…Electromagnetics‐based sensing is also expanding in medicine, bacteria and virus detection, and imaging, because of their customizable characteristics. In the last few years, several studies have used sensing antennas in the radio frequencies ranges . The sensitivity of the designed sensor depends on the chosen operating frequency, the sample dielectric properties and size, and the form of the sample material (liquid, solid, gas, powder, etc).…”

Section: Introductionmentioning

confidence: 99%

“…The sensitivity of the designed sensor depends on the chosen operating frequency, the sample dielectric properties and size, and the form of the sample material (liquid, solid, gas, powder, etc). Correas‐Serrano et al and Elsheakh et al introduced a cavity resonator antenna to sense the bacteria at a frequency range of 2.4 GHz, based on the proximity coupled feed method. The antenna was designed on Rogers substrate with thickness 1.28 mm and size 50 mm×50 mm.…”

Section: Introductionmentioning

confidence: 99%

“…In the last few years, several studies have used sensing antennas in the radio frequencies ranges. [24][25][26][27][28] The sensitivity of the designed sensor depends on the chosen operating frequency, the sample dielectric properties and size, and the form of the sample material (liquid, solid, gas, powder, etc). Correas-Serrano et al 26 and Elsheakh et al 27 introduced a cavity resonator antenna to sense the bacteria at a frequency range of 2.4 GHz, based on the proximity coupled feed method.…”

Section: Introductionmentioning

confidence: 99%

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Using millimeter‐waves for rapid detection of pathogenic bacteria in food based on bacteriophage

Sultan

Ali

Fahmy

et al. 2019

Engineering Reports

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The accessibility of a rapid method for detection and identification of food‐borne pathogens is crucial for food industry worldwide. Antibiotic resistance bacteria (eg, E. coli) that can enter the food chain in different ways, can indeed survive on foods causing disease to humans. Hence, the introduction of a rapid detection technology becomes necessary for the food industry to ensure consumer safety, especially for products with short shelf lives. Bacteriophages can be used to detect and identify bacteria. In this study, a novel biosensor is proposed to detect pathogens by means of phage‐based baroreceptor. The biosensing technique is based on millimeter‐waves technology in the 30 to 60 GHz frequency range. The proposed biosensor can detect the pathogenic bacteria in different food samples by using a diamond‐shape microstrip slot antenna. The bacteriophage‐bacterium interaction is detected through the dynamic changes in transmission lines and antennas responses. The correctness of the antenna to detect E. coli in real food sample (tomato) is also investigated. The results indicate that, through the designed sensing elements, the transient interaction between bacteria and phage can effectively be detected. This sensing mechanism allows for a faster, more accurate, and low‐cost detection of pathogenic bacteria than traditional assays. Finally, the results are compared with previously reported sensing techniques.

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Nonreciprocal Graphene Devices and Antennas Based on Spatiotemporal Modulation

Cited by 117 publications

References 19 publications

Breaking temporal symmetries for emission and absorption

Breaking temporal symmetries for emission and absorption

Electrically tunable harmonics in time-modulated metasurfaces for wavefront engineering

Using millimeter‐waves for rapid detection of pathogenic bacteria in food based on bacteriophage

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