scholarly journals A Graphene-Based THz Wave Duplexer and Filter: Switching via Gate Biasing

2021 ◽  
Author(s):  
AmirAli Mohammad Khani
Keyword(s):  
Silicon Dioxide ◽  
Equivalent Circuit ◽  
Frequency Range ◽  
Ideal Candidate ◽  
Simulation Results ◽  
Rlc Circuits ◽  
Incident Waves ◽  
Reconfigurable Device ◽  
Thz Waves ◽  
Transmission And Reflection

Abstract This work introduces a Graphene-based multi-layer reconfigurable device as a wave duplexer in the THz frequency range. Adjusting transmitting and reflecting parts of incident waves alongside controlling absorption provides the interesting capability to select target waves in different frequencies. The proposed device includes periodic graphene patterns on both sides of silicon dioxide as substrate. Additionally, the patterns are biased differently compared to conventional patterns which makes it possible to achieve two distinct behaviors versus frequency. Exploiting equivalent circuit models (ECM) for graphene and dielectric, the whole device is modeled by passive RLC circuits. According to simulation results, the proposed device can transmit and reflect incident THz waves at desired frequencies in 0.1 THz to 30 THz which makes it an ideal candidate for manipulating THz waves in terms of transmission and reflection.

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.

Resonant Characteristics of Split Ring Resonator and Unit Cell for Periodic Metamaterial Devices

2021 ◽  
Vol 35 (11) ◽  
pp. 1378-1379
Author(s):  
Brinta Chowdhury ◽  
Thisara Walpita ◽  
B. Yang ◽  
A. Eroglu
Keyword(s):  
Equivalent Circuit ◽  
Ring Resonator ◽  
Equivalent Circuit Model ◽  
Split Ring Resonator ◽  
Circuit Model ◽  
Split Ring ◽  
Analytical Formulation ◽  
Lumped Element ◽  
Ring Structures ◽  
Simulation Results

The resonant characteristics of single split ring resonator-based metamaterial devices with single gap are presented using the analytical formulation developed for the lumped element equivalent circuit model. The characteristics of the metamaterial resonators have been investigated for different ring sizes, gap widths and substrate permittivity. Equivalent circuit model is developed for two ring structures. The analytical, and simulation results are compared and verified. The prototype has been then built and measured. It has been observed that all the results agree. The results presented in this paper can be used to develop devices at the THz range that can operate as sensors, antennas or tuning elements.

scholarly journals Design and Development of a Wideband Planar Yagi Antenna Using Tightly Coupled Directive Element

Micromachines ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 975
Author(s):  
Muhammad A. Ashraf ◽  
Khalid Jamil ◽  
Ahmed Telba ◽  
Mohammed A. Alzabidi ◽  
Abdel Razik Sebak
Keyword(s):  
Reflection Coefficient ◽  
Wireless Communication ◽  
Radiation Pattern ◽  
Excellent Agreement ◽  
Frequency Range ◽  
Fractional Bandwidth ◽  
Yagi Antenna ◽  
Tightly Coupled ◽  
Simulation Results ◽  
Novel Concept

In this paper, a novel concept on the design of a broadband printed Yagi antenna for S-band wireless communication applications is presented. The proposed antenna exhibits a wide bandwidth (more than 48% fractional bandwidth) operating in the frequency range 2.6 GHz–4.3 GHz. This is achieved by employing an elliptically shaped coupled-directive element, which is wider compared with other elements. Compared with the conventional printed Yagi design, the tightly coupled directive element is placed very close (0.019λ to 0.0299λ) to the microstrip-fed dipole arms. The gain performance is enhanced by placing four additional elliptically shaped directive elements towards the electromagnetic field’s direction of propagation. The overall size of the proposed antenna is 60 mm × 140 mm × 1.6 mm. The proposed antenna is fabricated and its characteristics, such as reflection coefficient, radiation pattern, and gain, are compared with simulation results. Excellent agreement between measured and simulation results is observed.

Closed Loop Resonator Based Compact UWB Antenna with Single Notched Band Varying between WLAN and X-band for UWB Applications

Frequenz ◽  
2020 ◽  
Vol 74 (5-6) ◽  
pp. 201-209
Author(s):  
Mohammad Ahmad Salamin ◽  
Sudipta Das ◽  
Asmaa Zugari
Keyword(s):  
Closed Loop ◽  
Ground Plane ◽  
Frequency Range ◽  
Uwb Antenna ◽  
Notched Band ◽  
X Band ◽  
Compact Size ◽  
Simulation Results ◽  
Uwb Applications ◽  
Good Agreement

AbstractIn this paper, a novel compact UWB antenna with variable notched band characteristics for UWB applications is presented. The designed antenna primarily consists of an adjusted elliptical shaped metallic patch and a partial ground plane. The proposed antenna has a compact size of only 17 × 17 mm2. The suggested antenna covers the frequency range from 3.1 GHz to 12 GHz. A single notched band has been achieved at 7.4 GHz with the aid of integrating a novel closed loop resonator at the back plane of the antenna. This notched band can be utilized to alleviate the interference impact with the downlink X-band applications. Besides, a square slot was cut in the loop in order to obtain a variable notched band. With the absence and the existence of this slot, the notched band can be varied to mitigate interference of the upper WLAN band (5.72–5.82 GHz) and X-band (7.25–7.75 GHz) with UWB applications. A good agreement between measurement and simulation results was achieved, which affirms the appropriateness of this antenna for UWB applications.

Modeling and Simulation of the New Thin Film Transformer Equivalent Circuit

2013 ◽  
Vol 785-786 ◽  
pp. 1273-1277
Author(s):  
Xiao Ping Hu ◽  
Liang Zheng ◽  
Ye Long Zhong ◽  
Li Yun Ye
Keyword(s):  
Thin Film ◽  
Modeling And Simulation ◽  
Equivalent Circuit ◽  
Circuit Modeling ◽  
Automatic Extraction ◽  
S Parameter ◽  
Equivalent Circuit Modeling ◽  
Equivalent Circuit Parameters ◽  
Simulation Results

We research the new thin film transformer equivalent circuit modeling, simulate and modify the traditional estimate formula of the transformer equivalent circuit parameters, in order to attain the automatic extraction of thin film transformer parameters. This paper used MATLAB and Agilent ADS on the thin film transformers for the S parameter simulation. The simulation results show the estimation has better accurate and universal, it also shows the effect of different number of turns and thin film materials on the properties of thin film transformer.

scholarly journals Iterative Analysis of Dielectric Constant of Patch Antenna Substrate at UHF Band

2018 ◽  
Vol 7 (2.16) ◽  
pp. 7
Author(s):  
Amish Kumar Jha ◽  
Bharti Gupta Gupta ◽  
Preety D Swami
Keyword(s):  
Dielectric Constant ◽  
Material Properties ◽  
Patch Antenna ◽  
Dielectric Materials ◽  
Substrate Material ◽  
Frequency Range ◽  
Shape Model ◽  
Iterative Analysis ◽  
Working Frequency ◽  
Simulation Results

This paper presents an investigation of effect of substrate material properties on the performance of antenna. The simulations are tested for 30 different dielectric materials on the basic RPA antenna model as well as on the most common U shape model using CST Microwave Studio. Two designs are proposed. On the basis of simulation results it has been concluded that for the first design the best material is which has a dielectric constant of 2.7 (𝜀r = 2.7) with bandwidth improvements of around 69.33% to 88.6% as compared to the most frequently used materials at present. For the second design the best result is obtained for the material that has dielectric constant in the range 2.0 to 2.7.  For a material having dielectric constant of 2.1 (𝜀r = 2.1) bandwidth improvement of around 11.74% with respect to RT Duroid was observed. For the second design, radiations from all other materials were not available in the working frequency range of 1GHz to 6GHz.  

scholarly journals Terahertz Hollow Core Antiresonant Fiber with Metamaterial Cladding

Fibers ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 14 ◽  
Author(s):  
Jakeya Sultana ◽  
Md. Saiful Islam ◽  
Cristiano M. B. Cordeiro ◽  
Alex Dinovitser ◽  
Mayank Kaushik ◽  
...  
Keyword(s):  
Photonic Crystal ◽  
Terahertz Radiation ◽  
Single Mode ◽  
Hollow Core ◽  
Crystal Fiber ◽  
Higher Order Modes ◽  
Metallic Inclusions ◽  
Simulation Results ◽  
Lower Loss ◽  
Thz Waves

A hollow core antiresonant photonic crystal fiber (HC-ARPCF) with metal inclusions is numerically analyzed for transmission of terahertz (THz) waves. The propagation of fundamental and higher order modes are investigated and the results are compared with conventional dielectric antiresonant (AR) fiber designs. Simulation results show that broadband terahertz radiation can be guided with six times lower loss in such hollow core fibers with metallic inclusions, compared to tube lattice fiber, covering a single mode bandwidth (BW) of 700 GHz.

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.

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