scholarly journals A THz Coupler based on Graphene Patterns with SU-8 Photoresist Dielectric Layer

2021 ◽  
Author(s):  
Elham Zandi
Keyword(s):  
Optical Sensors ◽  
Layer Structure ◽  
Equivalent Circuit Model ◽  
High Sensitivity ◽  
Frequency Range ◽  
Reflection And Transmission ◽  
Full Wave ◽  
Tunable Device ◽  
Indoor Communications ◽  
Simulation Results

Abstract Leveraging both method and concept, a novel multi-layer structure based on Graphene patterns and SU-8 photoresist dielectric is proposed at THz frequency range. By considering reflection and transmission channels as outputs, a simple THz coupler is provided. The structure is described exploiting equivalent circuit model while results are verified by full wave simulations. According to simulation results, the proposed device is able to reflect and transmit THz waves with high sensitivity versus gate biasing. The operation involves five bands in entire THz spectrum while the structure behavior can be adjusted by external gate biasing. Such a tunable device is in great demand to realize optical sensors and systems in several fields from indoor communications, security and medical imaging.

Design of multi-layered bandpass filter with independently controllable triple-passband response

2014 ◽  
Vol 6 (6) ◽  
pp. 611-618 ◽  
Author(s):  
Yung-Wei Chen ◽  
Hung-Wei Wu ◽  
Yan-Kuin Su
Keyword(s):  
Frequency Response ◽  
Bandpass Filter ◽  
Bottom Layer ◽  
Wide Frequency Range ◽  
Electromagnetic Simulation ◽  
Frequency Range ◽  
High Isolation ◽  
Full Wave ◽  
Simulation Results ◽  
Good Agreement

In this paper, a new multi-layered triple-passband bandpass filter using embedded and stub-loaded stepped impedance resonators (SIRs) is proposed. The filter is designed to have triple-passband at 1.8, 2.4, and 3.5 GHz. The 1st and 2nd passbands (1.8/2.4 GHz) are simultaneously generated by controlling the impedance and length ratios of the embedded SIRs (on top layer). The 3rd passband (3.5 GHz) is generated by using the stub-loaded SIR (on bottom layer). Using the embedded SIR, the even modes can be tuned within very wide frequency range and without affecting the odd modes. Therefore, the design of multi-band filters with very close passbands can be easily achieved and having a high isolation between the passbands. The filter can provide the multi-path propagation to enhance the frequency response and achieving the compact circuit size. The measured results are in good agreement with the full-wave electromagnetic simulation results.

A Modeling Method of Wideband Devices Based on Modified Nodal Analysis

2012 ◽  
Vol 182-183 ◽  
pp. 1323-1327
Author(s):  
Feng Lu ◽  
Jia Lu
Keyword(s):  
Equivalent Circuit Model ◽  
Measured Data ◽  
Model Fit ◽  
Maximum Relative Error ◽  
Frequency Range ◽  
Circuit Partitioning ◽  
Nodal Analysis ◽  
Modified Nodal Analysis ◽  
Simulation Results ◽  
Verification Process

According to the simplified circuit partitioning principle, this paper improves the Modified Nodal Analysis(MNA) of wideband Equivalent Circuit Model(ECM). The form of upconversion impedance is transformed from series into parallel. The results show that in the parallel form, the verification process of impedance type has been eliminated and it will not introduce new nodes. At the same time, the amount of computation has been reduced. The maximum relative error of measured data with this model fit is less than 0.693%. The simulation results and ECM test data are consistent with better at 0 to 8GHz frequency range.

Millimeter Wave Characterization of Wire Bond Transitions for W-Band Electromagnetic Sensor

2015 ◽  
Vol 738-739 ◽  
pp. 103-106
Author(s):  
Yong Fang ◽  
Bao Qing Zeng ◽  
Wen Tao Zhang ◽  
Pu Wang
Keyword(s):  
Equivalent Circuit ◽  
Millimeter Wave ◽  
Equivalent Circuit Model ◽  
Single Wire ◽  
Full Wave ◽  
Wire Bond ◽  
W Band ◽  
Electromagnetic Sensor ◽  
Simulation Results ◽  
Lumped Equivalent Circuit

This paper presents millimeter wave characterization and models of various wire bond transitions between chip’s ground-signal-ground pad (GSG) and microstrip (MS), include single-wire-nomatch MS-GSG transition, double-wire-nomatch MS-GSG, single-wire-match MS-GSG transition, and double-wire-match MS-GSG transition. It also presents the 3D full-wave electromagnetic simulation. Analysis results show that the double-wire-match MS-GSG transition’s characteristic is better than other three transitions in the whole W band. The accurate extracted parameter values are used for the lumped equivalent circuit model, whose simulation results are good with the full wave simulation results. The error between lumped equivalent circuit and full-wave models is of the order of ±0.2dB for S11 and S21 in the frequency range 75 - 105GHz. The proposed lumped equivalent circuit is suitable to be implemented in commercial microwave CAD tools for the electromagnetic sensor designing.

A Research for Broadband Modeling Method of Electro-Absorption Modulator

2011 ◽  
Vol 130-134 ◽  
pp. 3242-3246
Author(s):  
Jian Wu ◽  
Qian Zhao
Keyword(s):  
Equivalent Circuit ◽  
Relative Error ◽  
Measurement Data ◽  
Equivalent Circuit Model ◽  
Modeling Method ◽  
Maximum Relative Error ◽  
Frequency Range ◽  
Circuit Partitioning ◽  
Impedance Model ◽  
Simulation Results

This paper improves the broadband equivalent circuit model (ECM) modeling method of Electro-absorption Modulator. According to the principle of Circuit Partitioning Simplified, the series form of the original increased frequency impedance model is transformed into the parallel form. The result shows that the new method eliminates the process of the impedance type verification, will not introduce new nodes, and reduces the computation. After testing, the maximum relative error of this model to fit measurement data is only 0.693%. This method’s simulation results are consistent with the test data of ECM better in 0-8GHz frequency range.

scholarly journals Analysis and Design of Ultra-Wideband 3-Way Bagley Power Divider Using Tapered Lines Transformers

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Khair Al Shamaileh ◽  
Abdullah Qaroot ◽  
Nihad Dib ◽  
Abdelfattah Sheta ◽  
Majeed A. Alkanhal
Keyword(s):  
Design Procedure ◽  
Ultra Wideband ◽  
Power Divider ◽  
Frequency Range ◽  
Analysis And Design ◽  
Wave Simulation ◽  
Full Wave ◽  
Quarter Wave ◽  
Simulation Results

An ultra-wideband (UWB) modified 3-way Bagley polygon power divider (BPD) that operates over a frequency range of 2–16 GHz is presented. To achieve the UWB operation, the conventional quarter-wave transformers in the BPD are substituted by two tapered line transformers. For verification purposes, the proposed divider is simulated, fabricated, and measured. The agreement between the full-wave simulation results and the measurement ones validates the design procedure.

scholarly journals Design of Low-Profile Frequency-Selective Rasorbers Based on Three-Legged Loaded Element

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Yu Qiang ◽  
Dongfang Zhou ◽  
Qikun Liu ◽  
Zhenning Yao
Keyword(s):  
Layer Structure ◽  
Equivalent Circuit Model ◽  
Bottom Layer ◽  
Frequency Selective Surface ◽  
Structure Model ◽  
Unit Cell Size ◽  
Low Profile ◽  
Simulation Results ◽  
Frequency Selective ◽  
Good Agreement

A novel low-profile dual-polarization frequency-selective rasorber (FSR) with a transmissive window in the absorption band is proposed in this paper. Based on the equivalent circuit model (ECM), the principles of the impedance design are theoretically derived. Then, a two-layer structure model is constructed. The top layer is composed of a lossy three-legged loaded element (TLLE), and the bottom layer is composed of a square ring bandpass frequency-selective surface (FSS). Furthermore, the strips are folded to reduce the unit cell size to stabilize the angular response. The maximum stable response angle increases from 20 to 40° due to the miniaturized design under both TE and TM polarization. The experimental results of the prototype are in good agreement with the simulation results, which validates the rationality of our design.

A Tri-band Angularly Stable Frequency Selective Surface with Controllable Resonances for EM Shielding

Frequenz ◽  
2020 ◽  
Vol 74 (1-2) ◽  
pp. 25-31 ◽  
Author(s):  
Fei Wang
Keyword(s):  
Layer Structure ◽  
Equivalent Circuit Model ◽  
Single Layer ◽  
Frequency Selective Surface ◽  
Electromagnetic Shielding ◽  
Low Profile ◽  
Stable Frequency ◽  
Simulation Results ◽  
Frequency Selective ◽  
The Operating Mechanism

AbstractIn the paper, a tri-band angularly stable frequency selective surface (FSS) with controllable resonances for electromagnetic shielding is proposed. Different from traditional single-layer structure, the FSS proposed is based on cascaded structure that creates three adjustable blocking bands around frequency 5.93 GHz, 7.33 GHz and 9.17 GHz, respectively. The designed FSS has a low profile with thickness of λ0/100, where the λ0 represents wavelength of the first band-stop resonance frequency. Besides, the proposed FSS exhibits stable frequency response up to 70° with respect to different polarizations. Therefore, this FSS is flexible and can be used in electromagnetic shielding field where needs conformal screen. To investigate and understand the operating mechanism better, a equivalent circuit model (ECM) is deduced and given in the Section 2, the calculated results match the full-wave EM simulation results perfectly. Finally, a prototype of this FSS is fabricated and measured, the measurement results are in accordance with the simulation results.

Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

1988 ◽  
Vol 46 ◽  
pp. 204-205
Author(s):  
Kazumichi Ogura ◽  
Michael M. Kersker
Keyword(s):  
High Resolution ◽  
Layer Structure ◽  
High Sensitivity ◽  
Beam Current ◽  
Electron Beam Current ◽  
Lattice Structures ◽  
Super Lattice ◽  
Different Types ◽  
Backscattered Electron ◽  
Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

scholarly journals Differentiating and quantifying exosome secretion from a single cell using quasi-bound states in the continuum

Nanophotonics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1081-1086 ◽  
Author(s):  
Abdoulaye Ndao ◽  
Liyi Hsu ◽  
Wei Cai ◽  
Jeongho Ha ◽  
Junhee Park ◽  
...  
Keyword(s):  
Single Cell ◽  
Optical Sensors ◽  
Figure Of Merit ◽  
Bound States ◽  
Single Cell Analysis ◽  
Optical Cavity ◽  
High Sensitivity ◽  
Cell Secretion ◽  
The Continuum ◽  
Refractive Index Detection

AbstractOne of the key challenges in biology is to understand how individual cells process information and respond to perturbations. However, most of the existing single-cell analysis methods can only provide a glimpse of cell properties at specific time points and are unable to provide cell secretion and protein analysis at single-cell resolution. To address the limits of existing methods and to accelerate discoveries from single-cell studies, we propose and experimentally demonstrate a new sensor based on bound states in the continuum to quantify exosome secretion from a single cell. Our optical sensors demonstrate high-sensitivity refractive index detection. Because of the strong overlap between the medium supporting the mode and the analytes, such an optical cavity has a figure of merit of 677 and sensitivity of 440 nm/RIU. Such results facilitate technological progress for highly conducive optical sensors for different biomedical applications.

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