Passive Split Ring Resonator for Continuous Physiological Sensing Through Conductivity Measurements

2013 ◽  
Author(s):  
Evan Baker ◽  
Noah Shaw ◽  
Chen Wang ◽  
Hao Zhang ◽  
Cheng Sun
Keyword(s):  
Resonant Frequency ◽  
Printed Circuit Board ◽  
Ring Resonator ◽  
Fdtd Method ◽  
Split Ring Resonator ◽  
Circuit Board ◽  
Q Factor ◽  
Split Ring ◽  
Resonator Structure ◽  
Radio Band

The Split Ring Resonator (SRR) has been developed and explored for a number of sensing technologies and devices. A SRR can be equivalently regarded as an LC circuit; changes in the dielectric environment will change the equivalent capacitance of the resonator, resulting in a shift of the resonant frequency as well as the quality factor (Q-factor).This makes the device a promising application for continuous personal health monitoring throughout the day. In this work, we are developing a passive radio frequency sensor based on ring resonator designs. The targeted frequency band is within 2.4–2.5GHz ISM (Industrial-Scientific-Medical radio band) and is available for medical devices. The resonator structure is first simulated using Finite Difference Time Domain (FDTD) method by CST Microwave Studio to determine the resonant frequency. Then for the experimental study, a microstrip transmission line with a double split ring resonator (DSRR) was fabricated on a printed circuit board (PCB) with biocompatible PVC coating on top. Tuning the thickness and material of the biocompatible coating can further improve the biocompatibility, Q-factor, and resulting sensitivity (mS) of the device. Reflection spectrum (S11) is measured using a network analyzer at 100 mW. The current design senses changes in conductivity down to 0.5 mS. By reducing coating thickness, reducing the spacing between resonators, and with more efficient resonator designs we expect to further improve this sensitivity. This sensor could be utilized by either implanted into the interstitial layer beneath the skin or embedded into a contact lens to sense tear salinity levels.

scholarly journals Complex Permittivity Characterization of Liquid Samples Based on a Split Ring Resonator (SRR)

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3385
Author(s):  
Jialu Ma ◽  
Jingchao Tang ◽  
Kaicheng Wang ◽  
Lianghao Guo ◽  
Yubin Gong ◽  
...  
Keyword(s):  
Resonant Frequency ◽  
Complex Permittivity ◽  
Ring Resonator ◽  
High Sensitivity ◽  
Split Ring Resonator ◽  
Debye Model ◽  
Split Ring ◽  
Liquid Samples ◽  
Microwave Sensor

A complex permittivity characterization method for liquid samples has been proposed. The measurement is carried out based on a self-designed microwave sensor with a split ring resonator (SRR), the unload resonant frequency of which is 5.05 GHz. The liquid samples in capillary are placed in the resonant zone of the fabricated senor for high sensitivity measurement. The frequency shift of 58.7 MHz is achieved when the capillary is filled with ethanol, corresponding a sensitivity of 97.46 MHz/μL. The complex permittivity of methanol, ethanol, isopropanol (IPA) and deionized water at the resonant frequency are measured and calibrated by the first order Debye model. Then, the complex permittivity of different concentrations of aqueous solutions of these materials are measured by using the calibrated sensor system. The results show that the proposed sensor has high sensitivity and accuracy in measuring the complex permittivity of liquid samples with volumes as small as 0.13 μL. It provides a useful reference for the complex permittivity characterization of small amount of liquid chemical samples. In addition, the characterization of an important biological sample (inositol) is carried out by using the proposed sensor.

scholarly journals Effect of Stripline Number on Resonant Frequency of Hexagonal Split Ring Resonator Metamaterial

2020 ◽  
Vol 9 (1) ◽  
pp. 26-30
Author(s):  
Romi Fadli Syahputra ◽  
Yan Soerbakti ◽  
Riad Syech ◽  
Erman Taer ◽  
Saktioto Saktioto
Keyword(s):  
Electromagnetic Field ◽  
Resonant Frequency ◽  
Ring Resonator ◽  
Negative Refractive Index ◽  
Split Ring Resonator ◽  
Electromagnetic Properties ◽  
Strip Line ◽  
Frequency Range ◽  
Split Ring ◽  
Resonant Frequency Shift

Piranti-piranti elektronik maupun optoelektronik yang efisien dan responsif saat ini tengah masif dikembangkan dalam beragam bentuk dan jenis. Meta-material merupakan rancangan optoelektronik yang unik dengan sifat elektromagnetik yang tidak ditemukan secara alami, salah satunya adalah peristiwa indeks bias negatif. Eksplorasi terhadap banyak ragam struktur metamaterial sangat penting dilakukan untuk mengidentifikasi karakteristik tiap struktur. Salah satu struktur metamaterial yang menarik dikaji adalah bentuk heksagonal. Penelitian ini menginvestigasi karakteristik frekuensi resonan dan distribusi medan elektromagnetik metamaterial split ring resonator heksagonal (SRR-H) yang dikombinasikan dengan stripe line (SL) berupa logam tembaga. Lebih lanjut, jumlah SL divariasikan dari 0 - 5 unit dan disimulasikan dalam medium udara dalam rentang frekuensi 1 – 7,5 GHz. Hasil simulasi menunjukan adanya pergeseran frekuensi resonan untuk tiap penambahan SL dalam rentang frekuensi 4,31 – 5,82 GHz. Sebaran medan listrik cenderung terpusat pada cincin resonator sedangkan medan magnet cenderung terdistribusi pada SL. Desain metamaterial SRR-H dengan 3 SL memberikan respon disipasi energi yang terkecil dengan medan E maksimum 2,59 kV×m-1 dan medan H maksimum 8,69 A×m-1. Desain SRR-H ini cukup potensial untuk diaplikasikan sebagai antena gelombang elektomagnetik yang efisien dan juga sebagai biosensor. Efficient and responsive electronic and optoelectronic devices are currently being massively developed in various forms and types. Metamaterial is a unique optoelectronic design with electromagnetic properties that are not found naturally, one of its properties is a negative refractive index. Exploration of different types of metamaterial structures is very important to identify the characteristics of each structure. One of the interesting metamaterial structures is a hexagonal shape. This research investigates the resonant frequency characteristics and electromagnetic field distribution of split-ring resonator (SRR-H) hexagonal-shaped metamaterial which is combined with the copper stripe line (SL). Furthermore, the number of SL is varied from 0 to 5 units and simulated in the air medium in frequency range of 1 - 7.5 GHz. The simulation results show a resonant frequency shift occurred for each SL combination in the 4.31 - 5.82 GHz frequency range. The distribution of the electric field tends to be concentrated on the resonator while the magnetic field tends to be distributed on the SL. The SRR-H metamaterial with 3 SL provides the smallest energy dissipation response with a maximum E field of 2.59 kV×m-1 and a maximum H field of 8.69 A×m-1. The SRR-H design is potential enough to be applied as an efficient electromagnetic wave antenna and also as a biosensor.Keywords: Metamaterials, SRR-H, strip line, resonant frequency, electromagnetic field

scholarly journals Metaheuristic Regression Equations for Split-Ring Resonator Using Time-Varying Particle Swarm Optimization Algorithm

Electronics ◽  
2018 ◽  
Vol 7 (11) ◽  
pp. 300
Author(s):  
Muhammad Mughal ◽  
Tahir Ejaz ◽  
Arshad ◽  
Ashiq Hussain
Keyword(s):  
Particle Swarm Optimization ◽  
Resonant Frequency ◽  
Quality Factor ◽  
Ring Resonator ◽  
Particle Swarm ◽  
Split Ring Resonator ◽  
Regression Equations ◽  
Time Varying ◽  
Split Ring ◽  
Swarm Optimization

This article presents a new technique for determining accurate values of resonant frequency and quality factor pertaining to the split-ring resonator. Different conducting shield materials have been used around a copper split-ring. The split-ring has been designed to operate at about 2.1 GHz. Various equations were worked out earlier to determine the values of resonant frequency and quality factor. However, these equations yielded different solutions. Therefore, simulations were used to obtain the values of the resonant frequency and quality factor of the split-ring resonator with different five-shield materials, using High-Frequency Structure Simulator (HFSS) software. In this work, a novel method has been introduced for obtaining values of resonant frequency which provides results with negligible error. An optimal technique, namely time-varying particle swarm optimization (TVPSO), was then performed to obtain two sets of equations for resonant frequency and quality factor. The two sets of equations, optimized using TVPSO, were compared for their effectiveness in matching the actual frequency and quality factor for each of the five materials. It was found that the TVPSO was significant in achieving the frequency and quality factor regression equation to accurately resemble the actual values portrayed by the low mean absolute error.

scholarly journals Shield Optimization and Formulation of Regression Equations for Split-Ring Resonator

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Tahir Ejaz ◽  
Hamood Ur Rahman ◽  
T. Tauqeer ◽  
Adnan Masood ◽  
Tahir Zaidi
Keyword(s):  
Resonant Frequency ◽  
Quality Factor ◽  
Ring Resonator ◽  
Low Cost ◽  
Split Ring Resonator ◽  
Ring Resonators ◽  
Regression Equations ◽  
Split Ring ◽  
Optimum Result ◽  
5 Ghz

Microwave resonators are widely used for numerous applications including communication, biomedical and chemical applications, material testing, and food grading. Split-ring resonators in both planar and nonplanar forms are a simple structure which has been in use for several decades. This type of resonator is characterized with low cost, ease of fabrication, moderate quality factor, low external noise interference, high stability, and so forth. Due to these attractive features and ease in handling, nonplanar form of structure has been utilized for material characterization in 1–5 GHz range. Resonant frequency and quality factor are two important parameters for determination of material properties utilizing perturbation theory. Shield made of conducting material is utilized to enclose split-ring resonator which enhances quality factor. This work presents a novel technique to develop shield around a predesigned nonplanar split-ring resonator to yield optimized quality factor. Based on this technique and statistical analysis regression equations have also been formulated for resonant frequency and quality factor which is a major outcome of this work. These equations quantify dependence of output parameters on various factors of shield made of different materials. Such analysis is instrumental in development of devices/designs where improved/optimum result is required.

scholarly journals A Novel Symmetrical Split Ring Resonator Based on Microstrip for Microwave Sensors

2016 ◽  
Vol 16 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Rammah A. Alahnomi ◽  
Z. Zakaria ◽  
E. Ruslan ◽  
Amyrul Azuan Mohd Bahar
Keyword(s):  
Insertion Loss ◽  
Ring Resonator ◽  
Performance Enhancement ◽  
Split Ring Resonator ◽  
Q Factor ◽  
Loose Coupling ◽  
Split Ring ◽  
Linear Coupling ◽  
High Q ◽  
Microwave Sensors

Abstract In this paper, novel symmetrical split ring resonator (SSRR) is proposed as a suitable component for performance enhancement of microwave sensors. SSRR has been employed for enhancing the insertion loss of the microwave sensors. Using the same device area, we can achieve a high Q-factor of 141.54 from the periphery enhancement using Quasi-linear coupling SSRR, whereas loose coupling SSRR can achieve a Q-factor of 33.98 only. Using Quasi-linear coupling SSRR, the Q-factor is enhanced 4.16 times the loose coupling SSRR using the same device area. After the optimization was made, the SSRR sensor with loose coupling scheme has achieved a very high Qfactor value around 407.34 while quasi-linear scheme has achieved high Q-factor value of 278.78 at the same operating frequency with smaller insertion loss. Spurious passbands at 1st, 2nd, 3rd, and 4th harmonics have been completely suppressed well above -20 dB rejection level without visible changes in the passband filter characteristics. The most significant of using SSRR is to be used for various industrial applications such as food industry, quality control, bio-sensing medicine and pharmacy. The simulation result that Quasi-linear coupling SSRR is a viable candidate for the performance enhancement of microwave sensors has been verified.

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.

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