A Simple and Efficient Method for Designing Broadband Terahertz Absorber Based on Singular Graphene Metasurface

In this paper, we propose a simple and efficient method for designing a broadband terahertz (THz) absorber based on singular graphene patches metasurface and metal-backed dielectric layer. An accurate circuit model of graphene patches is used for obtaining analytical expressions for the input impedance of the proposed absorber. The input impedance is designed to be closely matched to the free space in a wide frequency range. Numerical simulation and analytical circuit model results consistently show that graphene metasurface-based THz absorber with an absorption value above 90% in a relative bandwidth of 100% has been achieved.

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Mechanical Response of the Lungs at High Frequencies

Journal of Biomechanical Engineering ◽

10.1115/1.3426193 ◽

1978 ◽

Vol 100 (2) ◽

pp. 57-66 ◽

Cited By ~ 61

Author(s):

J. J. Fredberg ◽

A. Hoenig

Keyword(s):

Efficient Method ◽

High Frequency ◽

Input Impedance ◽

Mechanical Response ◽

Airway Wall ◽

Frequency Range ◽

Resonant Frequencies ◽

High Frequencies ◽

Branching Networks ◽

Adult Humans

We put forward an efficient method for computing the input impedance of complex asymmetrically branching duct networks, and apply this method to simulation of the dynamic response of the lungs of normal adult humans in the frequency range extending to 10,000 Hz. The results indicate that the response of comparable symmetric and asymmetric branching networks differ at high frequency (> 2 kHz in air), and that the airway wall response is an important factor in determining system damping and resonant frequencies.

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Detailed three-phase circuit model for power transformers over wide frequency range based on design parameters

Electric Power Systems Research ◽

10.1016/j.epsr.2012.06.015 ◽

2012 ◽

Vol 92 ◽

pp. 115-122 ◽

Cited By ~ 2

Author(s):

M. García-Gracia ◽

M. Villén ◽

M.A. Cova ◽

N. El Halabi

Keyword(s):

Wide Frequency Range ◽

Circuit Model ◽

Power Transformers ◽

Design Parameters ◽

Frequency Range ◽

Three Phase

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AC Equivalent Circuit Model of an Electrochemical Accelerometer for 3D Numerical Simulation in the Low-Frequency Range

Energies ◽

10.3390/en12244686 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4686

Author(s):

Qiuzhan Zhou ◽

Yuzhu Chen ◽

Jikang Hu ◽

Boshi Lyu

Keyword(s):

Numerical Simulation ◽

Equivalent Circuit ◽

Characteristic Curve ◽

Equivalent Circuit Model ◽

Low Frequency ◽

Circuit Model ◽

Frequency Range ◽

Element Analysis ◽

Amplitude Frequency Characteristic ◽

Vibration Sensors

The electrochemical principles presented in this paper can be applied to the manufacture of vibration sensors for oil and gas exploration, as well as long-period vibration sensors for the observation of natural earthquakes. To facilitate the manufacture of high-volume electrochemical accelerometer (EAM), this paper presents an AC equivalent circuit model of an EAM in a low-frequency range. A 3D time-dependent numerical simulation based on finite element analysis was designed to combine a complex chemical reaction with electric circuit theory. A sensitive chip channel model was constructed by using partial differential equations and the problem caused by a designed mathematical model was solved by using multi-physics finite element analysis. When the electrochemical properties of an electrochemical vibration sensor and its design parameters as well as the parameters of the AC equivalent circuit model are considered, the abstract processing of the sensor on the equivalent circuit is better accomplished. The effectiveness of the proposed simulation model and the equivalent circuit model were verified by comparing the amplitude-frequency characteristic curve of the equivalent circuit with the amplitude-frequency characteristic curve of the single-channel simulation model of the sensitive chip. These model not only have great significance for the design guidance of an external conditioning circuit but also provide an effective method to decouple the output signal and noise of the sensor reaction cavity.

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