A terahertz (THz) antenna with tunable filtering is designed and numerically studied. A slotted monopole radiator with defected ground structure is used for operating with wideband response with an impedance bandwidth in the range of 3.80-11.98 THz for ≤-10 . A slot is engraved in the radiator for obtaining the filtering characteristics in the antenna response. By varying its chemical potential, the frequency band 5.05-6.69 THz with graphene material can provide the tunability in the frequency and bandwidth of the filtered band in the antenna response. Furthermore, the antenna can provide radiation efficiency of more than 90% and gain with a peak value of 6.6 dBi in the passband.
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http://dx.doi.org/10.1364/AO.475609 | DOI Listing |
Sensors (Basel)
January 2025
Department of Electrical and Electronic Engineering, The University of Manchester, Manchester M13 9PL, UK.
In radio frequency identification (RFID), differences in spectrum policies and tag misreading in different countries are the two main issues that limit its application. To solve these problems, this article proposes a composite right/left-handed transmission line (CRLH-TL)-based reconfigurable antenna for ultra-high frequency near-field and far-field RFID reader applications. The CRLH-TL is achieved using a periodically capacitive gap-loaded parallel plate line.
View Article and Find Full Text PDFNano Lett
January 2025
Second Physics Institute, University of Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany.
Conducting polymers have emerged as promising active materials for metasurfaces due to their electrically tunable states and large refractive index modulation. However, existing approaches are often limited to infrared operation or single-polymer systems, restricting their versatility. In this Letter, we present organic metasurfaces featuring dual conducting polymers, polyaniline (PANI) and poly(3,4-ethylenedioxythiophene) (PEDOT), to achieve contrasting dynamic optical responses at visible frequencies.
View Article and Find Full Text PDFChem Asian J
January 2025
School of Materials and Chemistry, University of Shanghai for Science and Technology, Shanghai, 200093, China.
J Phys Chem B
January 2025
Dipartimento di Chimica e Chimica Industriale, Università di Pisa, via G. Moruzzi 13, 56124 Pisa, Italy.
Light-harvesting complexes (LHCs) play a critical role in modulating energy flux within photosynthetic organisms in response to fluctuating light. Under high light conditions, they activate quenching mechanisms to mitigate photodamage. Despite their importance, the molecular mechanisms underlying these photoprotective processes remain incomplete.
View Article and Find Full Text PDFSensors (Basel)
November 2024
Photonics Research Group, Department of Electrical and Information Engineering, Politecnico di Bari, 70126 Bari, Italy.
This study explores the achievement of a tunable true time-delay (TTD) system for a microwave phased-array antenna (MPAA) by incorporating the reversible phase-transition property of phase-change material (PCM) with Bragg gratings (BGs) and a cascade of three phase-shifted Bragg grating resonators (CPSBGRs). The goal was to design a low-power-consuming, non-volatile highly tunable compact TTD system for beam steering. A programmable on/off reflector was designed by changing a PCM-incorporated BG/CPSBGR from one phase to another.
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