Frequency-temperature sensitivity reduction with optimized microwave Bragg resonators

Floch, Jean-Michel Le; Murphy, Claire; Hartnett, John G.; Madrangeas, Valérie; Křupka, J.; Cros, Dominique; Tobar, Michael E.

doi:10.1063/1.4973676

Cited by 5 publications

(3 citation statements)

References 60 publications

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“…However, Ohmic loss at high frequency, e.g., the THz band, will become unacceptably high. For low-loss operation, all-dielectric mirrors were invented, such as photonic metasurface [ 58 , 59 ], gratings [ 60 , 61 ] or Bragg reflectors [ 7 , 8 , 62 ]. Bragg reflectors consist of alternating layers with high (

) and low (

) permittivity, whose thicknesses are respectively denoted as

and

(see Figure 5 a).…”

Section: Resultsmentioning

confidence: 99%

“…In the era of fifth-generation mobile networks, plenty of works have been devoted to developing integrable microwave components, such as microstrip antenna [ 1 ], circulators [ 2 ], capacitors [ 3 , 4 , 5 ], filters [ 6 ], low-loss waveguides [ 7 ], resonators [ 8 ] and multi-functional surface coatings [ 9 , 10 ]. To improve their electrical performance, miniaturization of device size and suppression of material loss are essential.…”

Section: Introductionmentioning

confidence: 99%

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Dielectric Properties of BaTiO3–Epoxy Nanocomposites in the Microwave Regime

2021

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We synthesized BaTiO3–epoxy nanocomposites (particle size < 100 nm) with volume fractions up to 25 vol. %, whose high-frequency complex permittivity was characterized from 8.2 to 12.5 GHz. The maximum dielectric constant approaches 9.499 with an acceptable loss tangent of 0.113. The dielectric loss gradually saturates when the particle concentration is higher than 15 vol. %. This special feature is an important key to realizing high-k and low-loss nanocomposites. By comparing the theoretical predictions and the experimental data, four applicable effective-medium models are suggested. The retrieved dielectric constant (loss tangent) of 100-nm BaTiO3 nanopowder is in the range of 50–90 (0.1–0.15) at 8.2–12.5 GHz, exhibiting weak frequency dispersion. Two multilayer microwave devices—total reflection and antireflection coatings—are designed based on the fabricated nanocomposites. Both devices show good performance and allow broadband operation.

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) and low (

) permittivity, whose thicknesses are respectively denoted as

and

(see Figure 5 a).…”

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dielectric Properties of BaTiO3–Epoxy Nanocomposites in the Microwave Regime

2021

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“…Nanophotonics encompasses an exciting field that focuses on light interactions with nanoscale materials. − The backbone of photonics is formed by light interaction resonances. − These resonances, have guided the use of the widely recognizable Fabry–Pérot and Bragg resonators as elemental blocks in complex optical devices with distinctive properties. − Nanophotonics research has advanced mainly due to the development of nanoscale materials with novel physical properties. − Nanowires (NWs) are essential building blocks for energy device design in nanophotonics because of the capable of supporting propagating 1D surface plasmons. − In cases where the NW length exceeds the propagation distance of a plasmon, the NW can function as a plasmon waveguide, typically supporting multiple plasmon modes with transverse confinement along the NW surface. − Surface plasmon resonances (SPRs) define the collective charge oscillations, which, when integrated with semiconductors, can significantly influence the properties of photoelectric conversion systems. − …”

mentioning

confidence: 99%

Ultra-High-Responsivity Vertical Nanowire-based Phototransistor under Standing-Wave Plasmon Mode Interaction Induced by Near-Field Circular OLED

Asare‐Yeboah

et al. 2020

J. Phys. Chem. Lett.

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High-responsivity photodevices are strongly desired for various demanding applications, such as optical communications, logic circuits, and sensors. The use of quantum and photon confinement has enabled a true revolution in the development of high-performance devices. Unfortunately, many practical optoelectronic devices exhibit intermediate sizes where resonant enhancement effects seem to be insignificant. Here we design and fabricate an ultra-high-responsivity organic-light-emitting-diode-induced nanowire resonance phototransistor (ONRPT) based on standing-wave resonance in the nanoscale cavity, subjected to a nearfield light. Observations of the ONRPT in standing-wave resonance mode indicate a >10 4 enhancement in the on/off ratio and a six times higher subthreshold slope when compared with the ONRPT in non-resonance mode. The ONRPT, which leads itself to outstanding electrical and favorably stable performance, opens up a plethora of opportunities for high-efficiency energy devices and allows for nanowire applications in the solar cell, piezo-photonic detectors, and optical modulators.

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Simple thermal model to characterize dry and wet pulsed-tube cryocoolers

et al. 2021

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Cryogenic sapphire oscillators are unique three-dimensional structures that provide the highest performance local oscillators at short-term integration times. To further understand this device whose highest weakness is its sensitivity to temperature and reach its ultimate limit, we undertake a rigorous analysis of the properties of the cryocoolers with a simple thermal model. We show that the separation of variables is possible, as the cryocooler structure transfers heat from top to bottom and side to center independently. Comparisons between the modeling and experiments are consistent, and we illustrate where predictions using the established lumped element model work well with a test-set of valid conditions. With the aid of published data, we provide fittings of the thermophysical properties of air for temperatures less than 300K and pressures less than 1 atm.

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Frequency-temperature sensitivity reduction with optimized microwave Bragg resonators

Abstract: International audienc

Cited by 5 publications

References 60 publications

Dielectric Properties of BaTiO3–Epoxy Nanocomposites in the Microwave Regime

Dielectric Properties of BaTiO3–Epoxy Nanocomposites in the Microwave Regime

Ultra-High-Responsivity Vertical Nanowire-based Phototransistor under Standing-Wave Plasmon Mode Interaction Induced by Near-Field Circular OLED

Simple thermal model to characterize dry and wet pulsed-tube cryocoolers

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