scholarly journals Photo-Excited Switchable Terahertz Metamaterial Polarization Converter/Absorber

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1116
Author(s):  
Dingwang Yu ◽  
Yanfei Dong ◽  
Youde Ruan ◽  
Guochao Li ◽  
Gaosheng Li ◽  
...  
Keyword(s):  
Pump Beam ◽  
Surface Current ◽  
Split Ring Resonator ◽  
Beam Power ◽  
Polarization Converter ◽  
Split Ring ◽  
Dielectric Spacer ◽  
Physical Insight ◽  
Working Principle ◽  
Insight Into

In this paper, a photo-excited switchable terahertz metamaterial (MM) polarization converter/absorber has been presented. The switchable structure comprises an orthogonal double split-ring resonator (ODSRR) and a metallic ground, separated by a dielectric spacer. The gaps of ODSRR are filled with semiconductor photoconductive silicon (Si), whose conductivity can be dynamically tuned by the incident pump beam with different power. From the simulated results, it can be observed that the proposed structure implements a wide polarization-conversion band in 2.01–2.56 THz with the conversion ratio of more than 90% and no pump beam power incident illuminating the structure, whereas two absorption peaks operate at 1.98 THz and 3.24 THz with the absorption rates of 70.5% and 94.2%, respectively, in the case of the maximum pump power. Equivalent circuit models are constructed for absorption states to provide physical insight into their operation. Meanwhile, the surface current distributions are also illustrated to explain the working principle. The simulated results show that this design has the advantage of the switchable performance afforded by semiconductor photoconductive Si, creating a path towards THz imaging, active switcher, etc.

scholarly journals Multiband and multifunctional polarization converter using an asymmetric metasurface

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Negin Pouyanfar ◽  
Javad Nourinia ◽  
Changiz Ghobadi
Keyword(s):  
High Efficiency ◽  
Surface Current ◽  
Split Ring Resonator ◽  
Cross Polarization ◽  
Polarization Converter ◽  
Split Ring ◽  
Root Cause ◽  
Polarized Waves ◽  
Linearly Polarized ◽  
Measured Sample

AbstractA compact and asymmetric multi-band reflective polarization converter metasurface has been offered in this paper. The proposed simple converter can effectively convert an incident linearly polarized EM wave to its orthogonal counterpart and circular polarized waves (RHCP and LHCP) at two frequency bands. The design consists of a square with two curves on the top right and lower left corners and a square Split Ring Resonator (SRR) responsible for linear-to-linear and linear-to-circular polarization conversions, respectively. The simulated results show that the converter successfully transforms a y-polarized incident wave to its orthogonal counterpart in a frequency range of 15.5–16.5 GHz with unity conversion at 16 GHz and circularly-polarized (RHCP) wave at 13 GHz and (LHCP) at 18 GHz, verified through the fabricated and measured sample. Wide angular stability up to 60° oblique incidence along with high efficiency reveals the good applicability of the structure. Moreover, the root cause of the cross-polarization conversion has been analyzed and confirmed through Bi-Mode Foster equivalent circuit and surface current distribution as well. Finally, a fabricated prototype is tested to validate the simulated results through measurement.

scholarly journals Design and Analysis of Metamaterial based-check board AMC Backed EBG Antenna for Body Placement Applications

2021 ◽  
Vol 9 (2) ◽  
pp. 707-721
Author(s):  
Kunapareddy Koteswara Rao, Et. al.
Keyword(s):  
Return Loss ◽  
Surface Current ◽  
Satellite Communications ◽  
High Gain ◽  
Split Ring Resonator ◽  
Magnetic Conductor ◽  
Radiation Characteristics ◽  
Split Ring ◽  
Wireless Applications ◽  
Sar Analysis

In this paper a compact EBG antenna with Artificial Magnetic Conductor (AMC) is proposed for on body applications. The proposed antenna is designed with single SRR (split ring resonator) and double SRR to differentiate the performance of the proposed antenna. The proposed EBG antenna bending analysis is performed at different angles on human body to attain good radiation characteristics. The footprint of proposed antenna is of 0.2λ0*0.24λ0mm2 and AMC with dimension of 0.48λ0*0.48λ0 mm2.The proposed antenna is obtained good return loss and radiation characteristics when EBG antenna is placed on the human leg with an angle of 300 at corresponding operating frequencies 2.4GHz, 5.8GHz, 9GHz and 9.5GHz respectively. The obtained operating frequencies cover wireless applications such as GPS, ISM, and Radar and satellite communications. The proposed EBG antenna is obtained with high gain 7.05dBi at 9.5GHz operating frequency. The surface current distributions are obtained for the proposed antenna is of 137A/m. Good isometric radiation patterns are observed for the proposed antenna. The SAR analysis is performed when the EBG antenna is placed on the human leg at an angle of 30degree is of 1.23W/kg.

scholarly journals Penta band single negative meta-atom absorber designed on square enclosed star-shaped modified split ring resonator for S-, C-, X- and Ku- bands microwave applications

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Md. Rashedul Islam ◽  
Mohammad Tariqul Islam ◽  
Md. Moniruzzaman ◽  
Md. Samsuzzaman ◽  
Haslina Arshad
Keyword(s):  
Ring Resonator ◽  
Surface Current ◽  
Good Deal ◽  
Split Ring Resonator ◽  
Unit Cell ◽  
Q Factor ◽  
Split Ring ◽  
Ring Shape ◽  
Microwave Applications ◽  
Meta Atom

AbstractThis paper represents a penta band square enclosed star-shaped modified split ring resonator (SRR) based single negative meta-atom absorber (MAA) for multi-band microwave regime applications. FR-4 low-cost material has been used as a substrate to make the MAA unit cell with 0.101λ0 × 0.101λ0 of electrical size, where λ0 is the wavelength calculated at the lower resonance frequency of 3.80 GHz. There are two outer square split ring and one inner star ring shape resonator of 0.035 mm thickness of copper placed on the one side, and another side of the substrate has full copper to construct the desired unit cell. The MAA unit cell provides five absorption peaks of 97.87%, 93.65%, 92.66%, 99.95%, and 99.86% at the frequencies of 3.80, 5.65, 8.45, 10.82, and 15.92 GHz, respectively, which covers S-, C-, X-, and Ku- bands. The properties of MAA have been investigated and analyzed in the E-, H-fields and surface current. The EMR and highest Q factor of the designed MAA is 9.87 and 30.41, respectively, and it shows a single negative (SNG) property. Different types of parametric analysis have been done to show the better performance of absorption. Advanced Designed System (ADS) software has been used for equivalent circuit to verify the simulated S11 result obtained from the CST-2019 software. Experimental outcomes of the MAA unit cell have a good deal with the simulated result and measured result of the 24 × 20 array of unit cells also shown. Since the unit cell provides superior EMR, excellent Q-factor, and highest absorption so the recommended MAA can be effectively used as a penta band absorber in microwave applications, like notch filtering, sensing, reducing the unintended noise generated with the copper component of the satellite and radar antennas.

Dual-band reflection polarization converter for circularly polarized waves based on a zigzag asymmetric split ring resonator

2021 ◽  
Vol 129 (1) ◽  
pp. 014901
Author(s):  
Shengyuan Shi ◽  
Kefang Qian ◽  
Wentao Gao ◽  
Jing Dai ◽  
Minhua Li ◽  
...  
Keyword(s):  
Ring Resonator ◽  
Split Ring Resonator ◽  
Dual Band ◽  
Polarization Converter ◽  
Split Ring ◽  
Circularly Polarized ◽  
Polarized Waves

scholarly journals Design and Analysis of Patch Antenna for C, X, Ku Band Applications

2021 ◽  
Author(s):  
Shantha Selvakumari R ◽  
Vishnoo Priyaa P
Keyword(s):  
Resonant Frequency ◽  
Patch Antenna ◽  
Return Loss ◽  
Ring Resonator ◽  
Surface Current ◽  
Split Ring Resonator ◽  
Split Ring ◽  
Wireless Applications ◽  
Complementary Split Ring Resonator ◽  
Radar Applications

Abstract This paper presents the design and simulation of patch antenna loaded with metamaterial called Complementary Split Ring Resonator (CSRR) with increased gain and bandwidth suitable for wireless applications such as satellite, TV and radar applications. FR4 substrate with dielectric constant (εr ) of 4.4 is used. The radiating patch consists of CSRR structure fed by microstrip line to achieve triple(C, X, Ku ) band characteristics. The proposed antenna is designed and simulated using Ansys High Frequency Structural Simulator (HFSS). The proposed antenna with 4 rings having a resonant frequency of 7.662, 9.8510, 10.9455, 11.8410, 12.7365 and 13.7315GHz and the bandwidth of 230, 1090, 640, 580, 620 and 2000MHz respectively. The proposed antenna with 6 rings also having a resonant frequency of 7.7615, 9.9525, 11.0450, 11.9405 and13.7315GHz and bandwidth of 160, 1130, 490, 1360 and 1480MHz are achieved. The proposed antenna is analyzed in terms of return loss, VSWR, gain and bandwidth. The electric field and surface current distribution were observed for the proposed antenna having 6 rings.

EFFECT OF QUADRUPLE P-SPIRAL SPLIT RING RESONATOR (QPS-SRR) STRUCTURE ON MICROSTRIP PATCH ANTENNA DESIGN

2016 ◽  
Vol 78 (5-5) ◽  
Author(s):  
Nornikman Hassan ◽  
Mohamad Zoinol Abidin Abd. Aziz ◽  
Muhammad Syafiq Noor Azizi ◽  
Mohamad Hafize Ramli ◽  
Mohd Azlishah Othman ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Patch Antenna ◽  
Return Loss ◽  
Ring Resonator ◽  
Surface Current ◽  
Split Ring Resonator ◽  
Microstrip Patch Antenna ◽  
Split Ring ◽  
Microstrip Patch ◽  
Rectangular Patch

In this project, the different locations of the quadruple P-spiral split ring resonator (MI-SRR) structure are embedded in the basic rectangular patch antenna. It started with a basic rectangular microstrip patch antenna that simulated in CST Microwave Studio software. After that, four different locations (Location A, Location B, Location C and Location D) of QPS-SRR had chosen to compare its performance of return loss, resonant frequency, surface current radiation pattern, and gain. Location A is representing the antenna with the QPS-SRR at the center part of the patch while Location B has the QPS-SRR at the upper part of the FR-4 substrate. For the Location C and Location D represent the antenna with MI-SRR at the ground at antenna with MI-SRR at the other layer, respectively. Compared with the basic rectangular antenna with only – 27.082 dB, the best return loss was reached by Location A with - 34.199 dB with resonant frequency at 2.390 GHz, while the Location C only shifted the minor value to 2.394 GHz with only - 25.13 dB.

scholarly journals Metamaterial Inspired Microstrip Offset Feed Truncated Antenna for Automotive Radar Application

2019 ◽  
Vol 8 (4) ◽  
pp. 11815-11818
Keyword(s):  
Short Range ◽  
Ring Resonator ◽  
Surface Current ◽  
Split Ring Resonator ◽  
Current Gain ◽  
Automotive Radar ◽  
Split Ring ◽  
Complementary Split Ring Resonator ◽  
Rectangular Patch ◽  
Radar Applications

A state-of-the-art design of microstrip offset feed truncated antenna for automotive radar applications operating at 24 GHz UWB band is proposed. The rectangular patch is truncated and ring shaped co directional complementary split ring resonator is imprinted on edge truncated rectangular patch to radiate in the short-range radar UWB band. The proposed antenna with Codirectional complementary split ring resonator antenna is having measurement of 5.1 x 4.65 x1.6 mm3 with operating frequency ranges from 24.6 to 30.3 GHz.This work comprises the thorough inquiries such as return loss, distribution of surface current, gain and radiation pattern. With the help of parametric analysis width of slit (z), width of feed (Wf) and length of feed (lf) the dimension of the proposed antenna is obtained. Simulation have shown decent fairness which proves the feasibility of the projected antenna for the automotive short-range RADAR application.

scholarly journals Determination of Permittivity of Dielectric Analytes in the Terahertz Frequency Range Using Split Ring Resonator Elements Integrated with On-Chip Waveguide

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4264 ◽  
Author(s):  
Sae June Park ◽  
John Cunningham
Keyword(s):  
Ring Resonator ◽  
Target Material ◽  
Surface Current ◽  
Split Ring Resonator ◽  
Frequency Range ◽  
Split Ring ◽  
Resonance Modes ◽  
Novel Method ◽  
On Chip

We investigate the use of finite-element simulations as a novel method for determining the dielectric property of target materials in the terahertz (THz) frequency range using split-ring resonator (SRR) sensing elements integrated into a planar Goubau line (PGL) waveguide. Five such SRRs were designed to support resonances at specific target frequencies. The origin of resonance modes was identified by investigating the electric field distribution and surface current modes in each SRR. Red-shifts were found in the resonances upon deposition of overlaid test dielectric layers that saturated for thicknesses above 10 µm. We also confirmed that the SRRs can work as independent sensors by depositing the analyte onto each individually. The relation between the permittivity of the target material and the saturated resonant frequency was obtained in each case, and was used to extract the permittivity of a test dielectric layer at six different frequencies in the range of 200–700 GHz as an example application. Our approach enables the permittivity of small volumes of analytes to be determined at a series of discrete frequencies up to ~1 THz.

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