Measurement of Dielectric Constant of Thin Leaves by Moisture Content at 4mm Band

Helhel, Selçuk; Çolak, Bektaş; Özen, Şükrü

doi:10.2528/pierl09021605

Cited by 45 publications

(10 citation statements)

References 12 publications

(13 reference statements)

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“…The average water content was found to be 27.85%. According to [ 33 ] an empirical expression for the leaf relative complex permittivity as a function of the water content Mg is:

…”

Section: Methodsmentioning

confidence: 99%

A Computational Model for Path Loss in Wireless Sensor Networks in Orchard Environments

Anastassiu

Vougioukas

Fronimos

et al. 2014

Sensors

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A computational model for radio wave propagation through tree orchards is presented. Trees are modeled as collections of branches, geometrically approximated by cylinders, whose dimensions are determined on the basis of measurements in a cherry orchard. Tree canopies are modeled as dielectric spheres of appropriate size. A single row of trees was modeled by creating copies of a representative tree model positioned on top of a rectangular, lossy dielectric slab that simulated the ground. The complete scattering model, including soil and trees, enhanced by periodicity conditions corresponding to the array, was characterized via a commercial computational software tool for simulating the wave propagation by means of the Finite Element Method. The attenuation of the simulated signal was compared to measurements taken in the cherry orchard, using two ZigBee receiver-transmitter modules. Near the top of the tree canopies (at 3 m), the predicted attenuation was close to the measured one—just slightly underestimated. However, at 1.5 m the solver underestimated the measured attenuation significantly, especially when leaves were present and, as distances grew longer. This suggests that the effects of scattering from neighboring tree rows need to be incorporated into the model. However, complex geometries result in ill conditioned linear systems that affect the solver's convergence.

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“…The average water content was found to be 27.85%. According to [ 33 ] an empirical expression for the leaf relative complex permittivity as a function of the water content Mg is:

…”

Section: Methodsmentioning

confidence: 99%

A Computational Model for Path Loss in Wireless Sensor Networks in Orchard Environments

Anastassiu

Vougioukas

Fronimos

et al. 2014

Sensors

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“…On the other hand, the relative permittivity of dry leaves is usually ≈2. [ 39 ] Therefore, most of the variation in the capacitance is from the variation in d air , explaining why the elastically collapsible air pockets increase the sensitivity of the sensor.…”

Section: Figurementioning

confidence: 99%

Plant‐Based Biodegradable Capacitive Tactile Pressure Sensor Using Flexible and Transparent Leaf Skeletons as Electrodes and Flower Petal as Dielectric Layer

Elsayes

Sharma

Yiannacou

et al. 2020

Advanced Sustainable Systems

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In biomedical sciences, there is demand for electronic skins with highly sensitive tactile sensors, having applications in patient monitoring, human–machine interfaces, and on‐body sensors. In clinical applications, it would be especially beneficial if the sensors would be disposable. Here, an all plant‐material‐based biodegradable capacitive tactile pressure sensor for disposable electronic skins is reported. Silver‐nanowire‐coated leaf skeletons are used as breathable and flexible electrodes while freeze‐dried rose petals are used as the dielectric layer. The leaf skeleton electrodes have a rough fractal‐like architecture, which provides good adhesion to the silver nanowires and maintains interconnections between the silver nanowires when the electrodes are bent. The electrodes display low constant resistance up to curvature of 800 m−1. The rose petal dielectric layer has a multiscale 3D cell wall microstructure, which compresses elastically when subjected to pressure. The fabricated sensor can respond to pressures ranging from 0.007 to at least 60 kPa, with a maximum sensitivity of ≈0.08 kPa−1. The signal is stable for at least 5000 pressure cycles, after an initial break‐in period. Owing to the all biomaterial constituents, the sensor is biodegradable under aqueous conditions. The sensor is successfully applied as an e‐skin in touch sensing and gesture monitoring.

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“…They can be represented by a model to quantify the electromagnetic difference for P ‐ and X ‐bands . They can be represented by a model to quantify the electromagnetic wave penetration difference for P ‐ and X ‐bands . Their electromagnetic properties are strongly dependent on moisture gravimetric and its variation, that is, the dielectric properties are weather dependent .…”

Section: Interaction Between Incident Wave and Vegetation Canopymentioning

confidence: 99%

Numerical investigation of airborne radars for remote sensing applications

Costa

Silva

Mologni³

et al. 2014

Micro & Optical Tech Letters

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This article reports an accurate numerical investigation of some technological solutions for embedded airborne radars in the P‐ and X‐bands applied to remote sensing. The propagation analyses are based on transient and Floquet simulations by taken into account the influence of an entire fuselage from a commercial plane and the vegetation electromagnetic characteristics, similar to Amazon rainforest, to reproduce a realistic situation. Moreover, it is designed and analyzed a log‐periodic antenna with dual polarization for embedded airborne radars. The antenna analysis is based on S‐parameters and radiation pattern characteristics. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1473–1478, 2014

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Measurement of Dielectric Constant of Thin Leaves by Moisture Content at 4mm Band

Cited by 45 publications

References 12 publications

A Computational Model for Path Loss in Wireless Sensor Networks in Orchard Environments

A Computational Model for Path Loss in Wireless Sensor Networks in Orchard Environments

Plant‐Based Biodegradable Capacitive Tactile Pressure Sensor Using Flexible and Transparent Leaf Skeletons as Electrodes and Flower Petal as Dielectric Layer

Numerical investigation of airborne radars for remote sensing applications

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