A Dielectric Loss Model Based on Interfacial Electron Tunneling

A dielectric loss model based on the tunneling of electrons from metal electrodes into traps in the insulator near the interface is described. The temperature dependence of the losses is controlled primarily by the energy distribution of the traps and the frequency dependence is controlled by their spatial distribution. Traps distributed uniformly in both energy and space result in essentially temperature- and frequency-independent losses. The model predicts an inverse dependence of losses on sample thickness. The step-response currents for the tunnel mechanism become nonlinear at high applied fields; however, the detailed behavior is very sensitive to the trap distribution assumed. For a particular trap distribution it is possible to have a polarity-dependent, irreversible step response.

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A new path loss model based on the volumetric occupancy rate for the pine forests at 5G frequency band

International Journal of Microwave and Wireless Technologies ◽

10.1017/s175907872000152x ◽

2020 ◽

pp. 1-10

Author(s):

Abdullah Genc

Keyword(s):

Path Loss ◽

Forest Area ◽

Occupancy Rate ◽

Loss Model ◽

Path Loss Model ◽

Model Based ◽

Proposed Model ◽

Pine Trees ◽

Foliage Density ◽

Reference Measurements

Abstract In this paper, a new empirical path loss model based on frequency, distance, and volumetric occupancy rate is generated at the 3.5 and 4.2 GHz in the scope of 5G frequency bands. This study aims to determine the effect of the volumetric occupancy rate on path loss depending on the foliage density of the trees in the pine forest area. Using 4.2 GHz and the effect of the volumetric occupancy rate contributes to the literature in terms of novelty. Both the reference measurements to generate a model and verification measurements to verify the proposed models are conducted in three different regions of the forest area with double ridged horn antennas. These regions of the artificial forest area consist of regularly sorted and identical pine trees. Root mean square error (RMSE) and R-squared values are calculated to evaluate the performance of the proposed model. For 3.5 and 4.2 GHz, while the RMSEs are 3.983 and 3.883, the values of R-squared are 0.967 and 0.963, respectively. Additionally, the results are compared with four path loss models which are commonly used in the forest area. The proposed one has the best performance among the other models with values 3.98 and 3.88 dB for 3.5 and 4.2 GHz.

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Path loss model based on cluster at 28 GHz in the indoor and outdoor environments

Science China Information Sciences ◽

10.1007/s11432-017-9127-6 ◽

2017 ◽

Vol 60 (8) ◽

Cited By ~ 3

Author(s):

Lai Zhou ◽

Limin Xiao ◽

Zhi Yang ◽

Jiahui Li ◽

Jin Lian ◽

...

Keyword(s):

Path Loss ◽

Loss Model ◽

Path Loss Model ◽

Model Based ◽

Outdoor Environments ◽

Indoor And Outdoor Environments ◽

Indoor And Outdoor

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Graphene for Magnetoresistive Junctions

MRS Proceedings ◽

10.1557/opl.2011.646 ◽

2011 ◽

Vol 1284 ◽

Author(s):

J. Inoue ◽

T. Hiraiwa ◽

R. Sato ◽

A. Yamamura ◽

S. Honda ◽

...

Keyword(s):

Dirac Point ◽

Electron Tunneling ◽

Tight Binding ◽

Metal Electrodes ◽

Binding Model ◽

Transition Metal Alloys ◽

Dependent Change ◽

Band Mixing ◽

Junction Structure ◽

Very High

ABSTRACTInfluence of the linear energy-momentum relationship in graphene on conductance and magnetoresistance (MR) in ferromagnetic metal (FM)/graphene/FM lateral junctions is studied in a numerical simulation formulated using the Kubo formula and recursive Green’s function method in a tight-binding model. It is shown that the contribution of electron tunneling through graphene should be considered in the electronic transport in metal/graphene/metal junctions, and that the Dirac point (DP) is effectively shifted by the band mixing between graphene and metal electrodes. It is shown that MR appears due to spin-dependent shift of DP or spin-dependent change in the electronic states at DPs. It is shown that the MR ratio caused by the latter mechanism can be very high when certain transition metal alloys are used for electrodes. These results do not essentially depend on the shape of the junction structure. However, to obtain high MR ratios, the effects of roughness should be small.

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