scholarly journals Feasibility Study of Enhancing Microwave Brain Imaging Using Metamaterials

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5472 ◽  
Author(s):  
Eleonora Razzicchia ◽  
Ioannis Sotiriou ◽  
Helena Cano-Garcia ◽  
Efthymios Kallos ◽  
George Palikaras ◽  
...  
Keyword(s):  
Brain Imaging ◽  
Impedance Matching ◽  
Human Head ◽  
Split Ring Resonator ◽  
Case Scenario ◽  
Split Ring ◽  
Matching Layer ◽  
Dielectric Target ◽  
The Brain ◽  
Brain Haemorrhage

We present an approach to enhance microwave brain imaging with an innovative metamaterial (MM) planar design based on a cross-shaped split-ring resonator (SRR-CS). The proposed metasurface is incorporated in different setups, and its interaction with EM waves is studied both experimentally and by using CST Microwave Studio® and is compared to a “no MM” case scenario. We show that the MM can enhance the penetration of the transmitted signals into the human head when placed in contact with skin tissue, acting as an impedance-matching layer. In addition, we show that the MM can improve the transceivers’ ability to detect useful “weak” signals when incorporated in a headband scanner for brain imaging by increasing the signal difference from a blood-like dielectric target introduced into the brain volume. Our results suggest that the proposed MM film can be a powerful hardware advance towards the development of scanners for brain haemorrhage detection and monitoring.

Reduced Cross-Polarization Patch Antenna with Optimized Impedance Matching Using a Complimentary Split Ring Resonator and Slots as Defected Ground Structure

2021 ◽  
Vol 36 (6) ◽  
pp. 718-725
Author(s):  
Narayanasamy RajeshKumar ◽  
Palani Sathya ◽  
Sharul Rahim ◽  
Akaa Eteng
Keyword(s):  
Patch Antenna ◽  
Ring Resonator ◽  
Impedance Matching ◽  
Equivalent Circuit Model ◽  
Split Ring Resonator ◽  
Cross Polarization ◽  
Defected Ground Structure ◽  
Ground Structure ◽  
Split Ring ◽  
Surface Current Density

An innovative method is proposed to improve the cross-polarization performance and impedance matching of a microstrip antenna by integrating a complimentary split ring resonator and slots as a defected ground structure. An equivalent circuit model (ECM) enables the design take into consideration the mutual coupling between the antenna patch and the Defected Ground Structure. The input impedance and surface current density analysis confirms that the integration of a CSRR within a rectangular microstrip patch antenna leads to uniform comparative cross-polarization level below 40 dB in the H-plane, over an angular range of ± 50°. Introducing parallel slots, as well, leads to a reduction of spurious antenna radiation, thereby improving the impedance matching. Measurements conducted on a fabricated prototype are consistent with simulation results. The proposed antenna has a peak gain of 4.16 dB at 2.6 GHz resonating frequency, and hence is good candidate for broadband service applications.

scholarly journals Design of Cavity-Backed Bow-Tie Antenna with Matching Layer for Human Body Application

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 4015 ◽  
Author(s):  
Jeong ◽  
Park ◽  
Lee
Keyword(s):  
Reflection Coefficient ◽  
Human Body ◽  
Electromagnetic Interference ◽  
Impedance Matching ◽  
Human Head ◽  
Impedance Match ◽  
Broadband Antenna ◽  
Matching Layer ◽  
Antenna Performance ◽  
Bow Tie

This paper presents the broadband antenna for the microwave radiometric sensing of internal body temperature. For broadband operation, the bow-tie antenna was designed and backed with a cylindrical cavity, which decreased environmental electromagnetic interference and also improved the directivity of the antenna. The broadband impedance-transforming balun in microstrip form was also designed to feed the bow-tie antenna, and was located inside the cavity. An impedance-matching dielectric layer (IMDL) was introduced on top of the bow-tie antenna, for impedance match with the human body with high permittivity. The fabricated antenna was measured in free space with the IMDL removed, showing an input reflection coefficient lower than −10 dB from 2.64 to > 3.60 GHz with antenna gain over 6.0 dBi and radiation efficiency over 74.7% from 2.7 to 3.5 GHz. The IMDL was re-installed on the cavity-backed bow-tie antenna to measure the antenna performance for the human head with relative permittivity of about 40. The measured reflection coefficient was as low as −28.9 dB at 2.95 GHz and lower than −10 dB from 2.65 to > 3.5 GHz. It was also shown that the designed antenna recovered a good impedance match by adjusting the permittivity and thickness of the IMDL for the different parts of the human body with different permittivities.

scholarly journals A ring monopole quad band antenna loaded with metamaterial and slots for wireless applications

2021 ◽  
Vol 10 (5) ◽  
pp. 2716-2723
Author(s):  
Basavalinga Swamy ◽  
C. M. Tavade ◽  
Kishan Singh
Keyword(s):  
Radiation Pattern ◽  
Ring Resonator ◽  
Impedance Matching ◽  
Split Ring Resonator ◽  
Circular Ring ◽  
Metamaterial Structure ◽  
Split Ring ◽  
Wireless Applications ◽  
Matching Performance ◽  
Ground Part

The present wireless applications demand a compact, multi-operated, and stable radiation pattern antenna with good gain and impedance matching performance. To accomplish this requirement. In this paper, we propose a compact metamaterial structure loaded quad band antenna. The structural specifications/layout of the antenna consists of a circular ring monopole fed by a microstrip line. The ground part of the antenna is loaded with a metamaterial rectangular split-ring resonator (RSRR), an L-shaped slot, and two horizontally placed rectangular slots parallel to each other. No external matching circuit is utilized and impedance matching is solely controlled by the placement of slots. The antenna shows operation at 2.1 GHz (2.01-2.24 GHz, a bandwidth of 230 MHz (WLAN)), 4.5 GHz (4.35-4.66 GHz, a bandwidth of 310 MHz (C-band)), 5.5 GHz (5.37-5.77 GHz bandwidth of 400 MHz (WiMAX)), and 7.2 GHz (7.08-7.33 GHz, a bandwidth of 250 MHz (satellite band)). The antenna exhibits good gain and stable radiation pattern in both the plane and thus can be utilized for aforementioned applications.

scholarly journals Fractal Antenna Based on Split Ring Resonators with Defected Ground Structure

2020 ◽  
pp. 110-117
Author(s):  
Aruna R ◽  
Sreegiri S S
Keyword(s):  
Impedance Matching ◽  
Wide Band ◽  
Split Ring Resonator ◽  
Ring Resonators ◽  
Fractal Antenna ◽  
Defected Ground Structure ◽  
Ground Structure ◽  
Split Ring ◽  
Split Ring Resonators ◽  
Circular Patch

In this paper presents the design of a circular microstrip fractal antenna (CMFA) loaded with parasitic edge-coupled (EC) split ring resonators (SRR) and defected ground structure (DGS). The basic resonant structure is a circular patch antenna designed at 3.2 GHz on FR4 substrate with relative permittivity 4.4, and 1.6 mm thickness. One iteration of circular patch and slots is employed to form it fractal and so as to attain multiband performance, the antenna is inset fed by a 50? microstrip line. Further the work is extended to demonstrate the effect of placing split ring resonator to particular position of substrate, improves the impedance matching leading to improved bandwidth. In addition L shaped defected ground structures are used to improve the antenna performance. . A comparison between fractal antenna with and without SRRs and DGS is made and the results verifies that a better gain improvement and return loss. The dimensions of the antenna are 45 mm x 45 mm and it can be used for ultra wide band (UWB) applications.

scholarly journals A Split Ring Resonator-Based Metamaterial for Microwave Impedance Matching with Biological Tissue

2020 ◽  
Vol 10 (19) ◽  
pp. 6740
Author(s):  
Vincenza Portosi ◽  
Antonella Maria Loconsole ◽  
Francesco Prudenzano
Keyword(s):  
Biological Tissue ◽  
Ring Resonator ◽  
Impedance Matching ◽  
Split Ring Resonator ◽  
Scattering Parameter ◽  
Split Ring ◽  
Antenna Measurement ◽  
Microwave Beam ◽  
Hyperthermia Therapy ◽  
Promising Solution

A metamaterial lens based on a split ring resonator (SRR) array has been designed and optimized to improve the focusing and the penetration depth in human biological tissue of a microwave beam irradiated by a substrate integrated waveguide (SIW) cavity backed patch antenna. The impedance matching of the antenna loaded with human tissue is strongly improved. The simulations have been performed by using CST Microwave Studio®. A prototype of the device has been fabricated with the printed board circuits (PCB) process and has been characterized using a Network Analyzer and an antenna measurement system in anechoic chamber. A novel microwave applicator for hyperthermia therapy of skin cancer could be developed. The performances of the proposed applicator have been evaluated in terms of measured S11 scattering parameter modulus and simulated power loss density. The obtained results indicate that an SRR-based metamaterial is a promising solution for external microwave applicators to employ in dermatology.

scholarly journals Design and Implementation of a Multiband Metamaterial-Loaded Reconfigurable Antenna for Wireless Applications

2021 ◽  
Vol 2021 ◽  
pp. 1-21
Author(s):  
Ritesh Kumar Saraswat ◽  
Mithilesh Kumar
Keyword(s):  
High Speed ◽  
Satellite Communication ◽  
Ring Resonator ◽  
Impedance Matching ◽  
Ground Plane ◽  
Satellite System ◽  
Split Ring Resonator ◽  
Split Ring ◽  
System Service ◽  
Wireless Standards

This article presents a multiband antenna with the implementation of a metamaterial split-ring resonator (SRR), quasicomplementary split-ring resonator (CSRR), and slots to achieve octaband characteristics for wireless standards. Multiband features are accomplished by the implementation of the slot approach within the radiating section part and loading the SRR and CSRR cells. The electrical dimension is 0.256λ × 0.176 λ × 0.0128λ (32 × 22 × 1.6 mm3) of the proposed design, at a lower frequency of 2.4 GHz. The proposed design indicates the frequency-band reconfigurability nature by using the switching PIN diode placed at the slotted section of the ground plane. During the OFF state of switching, the element structure resonates in eight wireless communication bands covering various high-speed multiple applications of Internet of Things (IoT) regarding wireless standards S-band WLAN (WiFi, Bluetooth, Z-wave, wireless HART, and WBAN), lower C-band (WAIC, satellite communication transmission application), C-band WLAN, X-band (ITU region 2), Ku-band (direct broadcast satellite system and terrestrial microwave communication system service), and K-band (radar communication application) at 2.4, 4.3, 5.8, 8.5, 11.1, 13.9, 16.1, and 18.9 GHz, respectively, with S11 ≤ −10 dB. The antenna achieves an optimum peak gain of 4.23 dBi and radiation efficiency of 82.78% at operating frequency regarding wireless standards. The average efficiency of the proposed design is more than 70% for all resonant modes. The radiation characteristics (gain/efficiency/patterns/impedance matching) are shown in the stable and improved form at achieved wireless modes.

Split ring resonator inspired microstrip filtenna for Ku-band application

2017 ◽  
Vol 50 (4-6) ◽  
pp. 391-403 ◽  
Author(s):  
Soumya RANJAN MISHRA ◽  
K. L. SHEEJA ◽  
Nagendra P. PATHAK
Keyword(s):  
Ring Resonator ◽  
Split Ring Resonator ◽  
Split Ring ◽  
Ku Band
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