Double Ring Resonator Research Articles

Detection of Water Quality using Defected Ground Double Split Ring Resonator

Water is an essential thing for life. Now days due to population growth and pollution, the quality of water is degraded. In this paper, a single element double split ring resonator (DSRR) has been presented as a sensor to detect the quality of water. Here, two square shape metallic split rings are designed along with the microstrip line. On the back side of the substrate, defected ground structure (DGS) is introduced. The resonant frequency of the resonator is 11.12 GHz. Quality of water is detected by the shift in S21 resonant frequency with the variation in transmission coefficient. This sensor can be used in our daily life to detect the quality of water and it may be useful in medical field also.

Real-time and hazard-free water quality monitoring based on microwave planar resonator sensor

This manuscript presents the development of a microwave microfluidic sensor for monitoring organic contaminants in water. This method offers a contactless, non-intrusive, and real-time monitoring system. The sensor is comprised of a compact double-ring resonator integrated with a 3D-printed microfluidic channel, operating at 4.5∼4.6 GHz with a quality factor of 120. The channel configuration on the resonator ensures maximum interaction between the electromagnetic field and the liquid sample and provides high sensitivity and resolution. The developed sensor was used to monitor organics (glucose, acetate and glucose-acetate mix) and the chemical oxygen demand (COD) standard (potassium hydrogen phthalate) in concentrations ranging from 50 to 800 mg/L as COD. The feasibility, reproducibility, and accuracy of the sensing platform was further validated by analyzing the S21 characteristic of the sensor. A monotonic decrease in the resonant amplitude of S21 was observed as the concentration of organics increased, with the sensitivity of 0.603 dB/COD [g/L], 0.087 dB/COD [g/L], 0.099 dB/COD [g/L] and 0.077 dB/COD [g/L] for potassium hydrogen phthalate, sodium acetate, glucose, and a glucose- acetate mixture, respectively. The findings support the capability of the microwave microfluidic sensor to detect dielectric properties variation associated with a minimum concentration of 17 mg/L glucose in water in real time. The response of the sensor was compared with conventional COD measurements using potassium dichromate digestion to compare the efficiency of the developed sensor with the spectrophotometric method to measure COD.

Temperature sensing system with high signal-to-noise ratio and large temperature sensing range based on multiwavelength Brillouin fiber laser

A double-ring resonator temperature sensing system based on a multiwavelength Brillouin fiber laser (MBFL) is proposed and demonstrated experimentally. In the two ring resonators, a 3.2-km long dispersion shifted fiber is used as the sensing fiber while a 3.2-km long dispersion compensating fiber is the reference. Second-order Stokes light generated by two gain fibers are used as the beat frequency to obtain the microwave signal. The frequency of the signal is 1.657 GHz, which avoids the low frequency noise region, and the signal has a high signal-to-noise ratio of 39 dB. A change in the center frequency of the beat frequency microwave signal accurately corresponds with the temperature changing. The sensitivity of temperature is 2.26 MHz / ° C in the condition of the sensing temperature being from 5°C to 85°C and the reference temperature being 25°C. Obviously, the MBFL can sense temperature not only below the reference but also above it; thus the scheme has a larger temperature sensing range.

Bandwidth enhancement of five-port reflectometer-based ENG DSRR metamaterial for microwave imaging application

A five-Port Reflectometer (FPR) with the integration of ultra-wideband (UWB) Epsilon Negative (ENG) Double Split Ring Resonator (DSRR) metamaterial array is introduced in this paper for microwave imaging (MWI) application. The designed DSRR consists of two concentric rings with a split in each which are spatially rotated by 180°, formed an inverted structure to exhibit a wide negative epsilon bandwidth of 187 % (from 0.5 GHz to 15 GHz). The FPR is designed using a ring junction topology and semi-circularly curved inter-port transmission lines (TLs) which are placed between five equally spaced ports. Localizing the DSRR metamaterial in a periodic array of 5 × 4 at the ground plane of FPR lead to 79.79 % fractional bandwidth and reflection coefficient within the operating frequencies of 0.991 GHz–2.2576 GHz. Equivalent circuit model has been alluded with an intricate description of different array configurations of the metamaterial unit cell. Comparison of EM simulation and circuit simulation has been performed to validate the equivalent circuit model. It is found that the existence of stray capacitance, Cstray which is represented by the DSRR configurations, significantly influenced the resonant frequency and bandwidth of FPR. Measured results of the proposed design suits well with the simulations and prove higher efficacious applicability of the proposed design for microwave imaging application. A comparison of the reconstructed image also proves its suitability for the microwave imaging application.

Broken Heart Shaped Monopole Antenna for WiMAX Applications

A monopole broken heart shaped antenna is presented in this article. The WiMAX band application has been taken as objective. The proposed antenna design is carried out in different iterations to obtain the required band. Proposed broken hearts shaped antenna works in the band from 3.2GHz – 4.1GHz.the heart shaped double slotted ring resonator (SRR) with two different radius is seen in the final iteration to enhance the bandwidth (900MHz), and gain (3dB). The other parameters such as VSWR (almost < 2 at WiMAX band), impedance (both real & imaginary), efficiency which is almost 89%has been noticed in this design. So, the proposed broken heart shaped monopole antenna which works at WiMAX band shows the moderate gain, size reduction omnidirectional pattern, high efficiency, etc. which are important in WIMAX application band.

A finite element method towards acoustic phononic crystals by weak formulation

A weak formulation method is presented to analyze the propagation of acoustic waves in periodic crystal-like systems called phononic crystals. First, a compact circle and double split ring resonators with high impedance contrast to air background are employed to compute band structures with not only real parts of wavevectors but also imaginary parts of them. Calculating the imaginary part, which directly predicts a propagation length in band gaps, is not readily available in previous studies. It analytically enables us to more understand the behavior of evanescent mode in band gaps. Moreover, we present that the weak formulation method is advantageous in calculating equi-frequency contour.

Terahertz optical characteristics of two types of metamaterials for molecule sensing.

We investigate spectral responses of two different terahertz (THz) metamaterials of double split ring resonator (DSRR) and the nano slot resonator (NSR) for molecule sensing in low concentration. Two different resonant frequencies of DSRR can be controlled by polarization angle of incident THz beam. For comparison of THz optical characteristics, two NSRs were made as showing the same resonant frequencies as DSRR's multimode. The monosaccharide molecules of glucose and galactose were detected by these two types of metamaterials matching the resonant frequencies in various concentration. NSR shows higher sensitivity in very low concentration range rather than DSRR, although the behavior was easily saturated in terms of concentration. In contrast, DSRR can cover more broad concentration range with clear linearity especially under high quality factor mode in polarization of 67.5 degree due to the Fano resonance. THz field enhancement distributions were calculated to investigate sensing performance of both sensing chips in qualitative and quantitative manner.

Gain and Bandwidth Enhancement of Microstrip Antenna Array using Double Square Split Ring Resonator FSS as a Superstrate for WiMax/WiFi/WLAN Applications

Gain and Bandwidth Enhancement of Microstrip Antenna Array using Double Square Split Ring Resonator FSS as a Superstrate for WiMax/WiFi/WLAN Applications

Pneumatically tunable microwave split ring resonators

We have investigated the operation of a coupled system of double split ring resonators (SRRs) to demonstrate the tunability by changing its physical layout. A pneumatic system is proposed to dynamically shift the structural arrangement of the coupled SRRs in response to the incident electromagnetic wave. It is executed by manipulating the lateral placement of the levitated bottom ring relative to the static ring in the top layer using various levels of pneumatic force. We reduced the electromagnetic interference by avoiding metallic components and improved the stability through the contactless operation. The proposed pneumatic system uses only the air to modulate the operational frequency of the coupled SRRs. Both the simulation and the experiment have shown the transition between the quasi-edge coupled and the broad-side coupled modes of the double SRRs shift the resonance frequency over 28% around 3.0 GHz. This pneumatic implementation brings a new method of reconfigurable SRRs.

Suppression of mutual coupling in rectangular dielectric resonator antenna arrays using Epsilon-Negative metamaterials (ENG)

ABSTRACTA double slotted symmetrical split ring resonator with an inductive stub in its inner ring is presented as a Single Negative Electric (SNG) metamaterial to suppress mutual coupling between two E-plane coupled microstrip line fed rectangular dielectric resonator antenna (RDRA) array. The proposed SRR exhibits two resonant frequencies and wide stop-bands. The -10 dB bandwidth of S21 from 2022MHz to 2720 MHz and from 2187 MHz to 3839 MHz are obtained for the first structure, #1, and the second structure, #2, respectively. By introducing an ENG layer between the two RDRAs, the experimental reduction in mutual coupling is more than 23 dB with a small frequency shift (∼ 20 MHz), while the impedance matching is improved. The radiation efficiency and total efficiency are increased while the far-field pattern in the E-plane is not disturbed.

Experimental investigations of wave-DSRR interactions in liquid-phase media

In this paper, the mechanical displacement and the resulting resonance shift of a basic double split ring resonator (DSRR) which is placed in different low-loss liquid-phase environments are experimentally demonstrated. Such resulting dynamic process is due to the wave-DSRR interactions and the induced electromagnetic attraction force when an incident electromagnetic wave with enhanced intensity acts on the DSRR. Low-loss liquids including polyalphaolefin and polydimethylsiloxane are used in this paper as the host media to clearly show the electromagnetic resonance and its resonance shift performances. These experimental investigations and the obtained results can create a completely different research direction for the application of metamaterials in liquid-phase environments.

Compact near zero index metasurface lens with high aperture efficiency for antenna radiation characteristic enhancement

In this paper, a high gain, aperture efficient, low profile compact, near zero index (NZI) metasurface (MS) lens antenna with enhanced radiation characteristic is proposed. A high-performance transmissive MS is designed by using modified double circular ring resonator as unit cell with measured 3 dB transmission band from 8.80 to 11.90 GHz. It is observed that a triple layer stacked MS lens has the maximum ability to converge the electromagnetic radiation. The focusing mechanism of multiple stacked MS is studied by using measured E- and H-plane radiation pattern plot and H-Field distribution. A high gain low profile antenna is designed by placing the proposed small single surface NZI MS lens over a microstrip patch antenna acting as a microwave source. The proposed NZI MS lens is found to increase the measured gain of E- and H-plane by 10.70 dB in boresight direction at operating frequency 10.15 GHz. The front to back ratio is improved by 8 and 3 dB in E- and H-plane, respectively. The proposed MS lens antenna is able to achieve a broadside gain of 97.50% of the maximum gain achieved due to ideal effective radiation surface.

Tunable graphene-silica hybrid metasurface for far-infrared frequency

We present graphene-based metasurface structure that is actively tuned over far infrared frequency range. Tunable metasurface is created by using single ring and double ring split ring resonator (SRR) and complementary split ring resonator (CSRR). Proposed metasurface structures are analysed over different graphene chemical potential. Results of different metasurface are compared in terms of their transmittance, reflectance, phase variation and phase difference. The modulation depth of the transmittance is achieved more than 90%. It is also observed that resonance response becomes stronger when higher chemical potential is applied to graphene metasurface. The designed graphene metasurface can be used as sensor, polarizer and modulator in modern photonics devices.

Dual mode modified double square ring resonator structure at 76 GHz

AbstractDual mode modified double square ring resonator (MDSRR) operating at 76 GHz millimeter‐wave has been simulated, and experimentally verified. MDSRR structure operates in two modes, metamaterial (MTM) mode and frequency selective surface (FSS) mode, depending on the direction of the electric field. The MDSRR in the MTM mode performs well at the desired frequency region by providing the highest insertion loss, S21, as reported in the literature with a loss of −0.5 dB. The electromagnetically induced transparency principle is applied to explain the loss reduction mechanism. The low losses MTM structure has the potential to enhance the performance of the radiating elements of the automotive radar systems. Conversely, in the FSS mode, the FSS characteristics of the proposed structure are numerically simulated and verified experimentally by changing the direction of the electric field along the x‐direction, in which the structure shows opposite behavior compared to the MTM performance. To demonstrate the validity of the FSS characteristics, the MDSRRs structure was tested using a waveguide measurement facility. The experiment results match well with that of the simulation, and wideband‐stop characteristics are introduced in the range of 74 GHz to 80.3 GHz.

Chaotic dynamics and optical power saturation in parity–time (PT) symmetric double-ring resonator

In this work, we report emergence of saturation and chaotic spiking of optical power in a double-ring resonator with balanced loss and gain, obeying the so-called parity–time symmetry. We have modeled the system using a discrete-time iterative equation known as the Ikeda map. In the linear regime, evolution of optical power in the system shows power saturation behavior below the PT threshold and exponential blowup above the PT threshold. We found that in the unbroken PT regime, optical power saturation occurs owing to the existence of stable stationary states, which lies on the surface of four-dimensional hypersphere. Inclusion of Kerr nonlinearity into our model leads to the emergence of a stable, chaotic and divergent region in the parameter basin for period-1 cycle. A closer inspection into the system shows us that the largest Lyapunov exponent blows up in the divergent region. It is found that the existence of high nonnegative largest Lyapunov exponent causes chaotic spiking of optical power in the resonators.

High-Sensitivity Microwave Sensor Based on An Interdigital-Capacitor-Shaped Defected Ground Structure for Permittivity Characterization.

This study proposes a high-sensitivity microwave sensor based on an interdigital-capacitor-shaped defected ground structure (IDCS-DGS) in a microstrip transmission line for the dielectric characterization of planar materials. The proposed IDCS-DGS was designed by modifying the straight ridge structure of an H-shaped aperture. The proposed sensor was compared with conventional sensors based on a double-ring complementary split ring resonator (CSRR), a single-ring CSRR, and a rotated single-ring CSRR. All the sensors were designed and fabricated on 0.76-mm-thick RF-35 substrate and operated at 1.5 GHz under unloaded conditions. Five different standard dielectric samples with dielectric constants ranging from 2.17 to 10.2 were tested for the sensitivity comparison. The sensitivity of the proposed sensor was measured by the shift in the resonant frequency of the transmission coefficient, and compared with conventional sensors. The experiment results show that the sensitivity of the proposed sensor was two times higher for a low permittivity of 2.17 and it was 1.42 times higher for a high permittivity of 10.2 when compared with the double-ring CSRR-based sensor.

带有同心双圆环谐振腔的MIM波导的Fano谐振特性研究

带有同心双圆环谐振腔的MIM波导的Fano谐振特性研究

High throughput and label-free particle sensor based on microwave resonators

We developed a novel particle sensor based on micro channels embedded in microwave resonators, which are fabricated by standard print circuit board manufacturing technology. The sensing frequency falls in the range 2–4 GHz, the widely used microwave S band. A 70 μm-particle can produce a frequency shift of 0.5 MHz in a sensor with 150 μm channel size, with a dwell time of 0.5 ms by using double split ring resonators. These resonator sensors may employ phase-locked loop in achieving a higher detection resolution.

Design and analysis of single loop and double loop photonic crystal ring resonator based on hexagonal lattice structure

Photonic Crystal (PC) based optical devices have been widely explored in recent era due to their capability of miniaturization and large-scale integration of optical and opto-electronic devices. In this paper, two dimensional PC based Single Loop, Double Loop (Horizontal) and Double Loop (Vertical) Ring Resonators using hexagonal lattice structure is designed and analyzed. It reports the Discrete Fourier Transform (DFT) analysis using Finite Difference Time Domain (FDTD) method and calculates the Photonic Band Gap (PBG) using Plane Wave Expansion (PWE) method. The comparative analysis of three configurations based on Q factor reports the outperformance of double loop photonic crystal ring resonator (PCRR) with lattice constants A = 30 and C = 30 at 1550 nm with Q factor 17,000. The Q factor for double loop horizontal and single loop structure is 16,300 and 15,500 at 1550 nm.

Wearable Ring Resonator Antenna

In this paper a metamaterial wearable antenna is proposed. The proposed design is based on a transmission line coupled to a pair of double ring resonators (DRRs) on an e‐textile substrate. The metallic antenna layer is fully embroidered providing both electromagnetic and mechanical good properties. The proposed design is validated by comparison of 3D electromagnetic simulations and measurements. The obtained results correspond to S11 < −29.5 dB with a gain of 9.64 dBi at resonance frequency and 93% efficiency covering a 160 MHz bandwidth. In addition, the effect of environmental condition such as temperature and humidity on antenna is reported. Results show the resonance frequency level shift in several climatic conditions. Moreover, the specific absorption rate (SAR) to preserve the human body safety from radiation is performed by means of numerical simulations, according to the international regulation. Experimental results confirm that the embroidered MTM antenna is a useful technique to control the propagation of signals on wearable applications.