Dual Resonance Research Articles

In-situ detection scheme for EGFR gene with temperature and pH compensation using a triple-channel optical fiber biosensor

An advanced multi-parameter optical fiber sensing technology for EGFR gene detection based on DNA hybridization technology is demonstrated in this paper. For traditional DNA hybridization detection methods, temperature and pH compensation can not be realized or need multiple sensor probes. However, the multi-parameter detection technology we proposed can simultaneously detect complementary DNA, temperature and pH based on a single optical fiber probe. In this scheme, three optical signals including dual surface plasmon resonance signal (SPR) and Mach-Zehnder interference signal (MZI) are excited by binding the probe DNA sequence and pH-sensitive material with the optical fiber sensor. The paper proposes the first research to achieve simultaneous excitation of dual SPR signal and Mach-Zehnder interference signal in a single fiber and used for three-parameter detection. Three optical signals have different sensitivities to the three variables. From a mathematical point of view, the unique solutions of exon-20 concentration, temperature and pH can be obtained by analyzing the three optical signals. The experimental results show that the exon-20 sensitivity of the sensor can reach 0.07 nm nM−1, and the limit of detection is 3.27 nM. The designed sensor gives a fast response, high sensitivity, and low detection limit, which is important for the field of DNA hybridization research and for solving the problems of biosensor susceptibility to temperature and pH.

Ultra narrowband perfect absorber for refractive index sensing applications in mid-infrared region

In this study, a novel narrowband perfect absorber (NPA) with dual band resonance frequencies is presented. The proposed NPA absorbs over 99% of the incident laser beam in both resonance modes and it indicates high quality factor (Q = 135.2) resonance which is the highest for a perfect absorber performing in the mid-infrared region. In this work, the charge and current distributions for the corresponding resonance modes are investigated. The absorbance spectrum of the electric and magnetic field distributions is also obtained for the corresponding resonance modes. Furthermore, the detecting performance of the NPA is analyzed by covering the proposed device with a cladding layer. The figure of merit (FOM) and refractive index sensitivity (RIS) of the structure are calculated. Due to its high quality factor, enhanced electric and magnetic field responses, near unity absorbance for both resonance modes and tunable detecting characteristics the proposed NPA can be used in spectroscopy applications.

Stepped Impedance feed reconfigurable slotted elliptical patch antenna with partial ground for wireless applications.

An elliptical patch antenna (EPA) is very useful micro strip patch antenna structure in wireless communications. It has less polarization and feeding problems. In this work, stepped impedance feed reconfigurable slotted elliptical patch antenna (SRSEPA) is proposed and the multi band radiation is achieved using dual resonators and dual PIN diodes. The switching of diodes made four modes of operation that allow multiple bands of operation. Mode 0,3 are triple and Mode 1,2 are dual and operations with different band widths. These different band width wireless communications that include ISM band and Ku and applications the partial ground made the antenna radiate with dipole radiation patters. The patch is printed on 0.8 mm thickness and 30 X 40 mm2 sized FR4 substrate with 4.2 substrate relative constant and 0.02 loss tangent. In this multiple slots are provided multiple bands and stepped impedance feeding technique is used. The antenna is designed and simulated using HFSS tool

Miniature Optical Fiber DNA Hybridization Sensor With Temperature Compensation Using a Gold Nanofilm-Coated Optical Fiber

DNA hybridization method is one of the most important techniques for detecting new disease genes. However, temperature cross-sensitivity is ubiquitously found in the DNA hybridization process, which may cause DNA damage and even produce false positives. An optical DNA hybridization sensor with temperature compensation based on dual surface plasmon resonance (SPR) effect by using a gold nanofilm coating optical fiber was proposed and demonstrated. Two parameters of DNA and temperature detection were realized by different functional modifications of the gold nanofilm. And a matrix equation was employed to analyze the relationship between two variables. Lung cancer-related genes exon-20 gene fragment was successfully detected in our work. From the theoretical and experimental results, the DNA detection limit was 9 nmol/L, and the temperature sensitivity reaches -1.74 nm/°C. The designed sensor could detect DNA with low concentration and measure temperature at the same time. The proposed sensor has the potential to be applied in disease marker gene detection with temperature compensation.

Electronically Controlled Frequency Agile Beam Scanning Reflectarray Antenna with Integrated Control Unit

This paper reports the design, development, fabrication, and testing of a 225-element reconfigurable reflectarray (RRA) antenna with frequency agility and beam steering capabilities. The 15 15 (18.75 cm) RRA operating in the Ku band downlink frequency range (11.8 -12.2 GHz) of fixed satellite services (FSS) produces dual resonances switched between uplink frequency range (15-18 GHz) of FSS and earth exploration satellite range of 9.5-9.8 GHz (X Band). To attain reconfigurable multiple resonances, the unit cell is designed with a Malta cross of varying slot lengths interconnected to a square ring via a PIN diode. In the OFF state of the PIN diode connected between the concentric elements, a phase variation of 360° is obtained at 12 GHz and 9.5 GHz by varying the size of the Malta cross. By increasing the width of the outer ring in the ON state of the PIN diode, a dual resonance is obtained at 12 GHz and 17 GHz with 360° phase agility. The beam scanning is attempted at X band frequency by controlling the capacitance offered by the varactor diode connected between an inductive element and Malta cross. The proposed RRA offers 22.16 dBi, 24.5 dBi and 18.43 dBi simulated gain at 17 GHz, 12 GHz, and 9.5 GHz respectively. The simulated sidelobe levels (SLLs) and cross-polarization levels are -14.7 dB and less than -32 dB respectively. The proposed compound reconfigurable reflectarray befits fixed and mobile satellites, earth exploration satellites, radiolocation, aeronautical radio navigation, and deep space research.

Exploring Perspectives on Engineering: Trajectories and Narratives

Engineering, a subject of empirical rigour with the axis of performing a practical function for a system or device user, continuously translates knowledge into social change through an ever-changing modern lens, retaining a dual resonance in the frame of professional evolution. Firstly, a progression of available conceptual knowledge and approaches will occur. This induces the change observed in professional structure and alteration in engineering role and character. These outcomes may be discussed through the path of the discipline’s professional trajectory in parallel with an engineer’s archetypal portrait, not with reference to scientific knowledge expansion, which is characteristic of different historical periods, but in terms of the development of engineering approaches. Although it is often overlooked, at the core of true engineering is a philanthropic heart and the desire to deliver a productive service. Thus, the second evolutionary force is effectively social and forward-looking in nature as public needs grow and diverge, addressed through innovation’s social role. The convergence of these two elementary dynamisms of conceptual and social roots, is exemplified in a case study on Kisiizi Hospital, which speaks directly to the aim of this study: to achieve a comprehensive view of the modern engineering mentality’s application in social settings.
 Propelled by interviews with engineers and project managers alongside primary studies, this exploration proposes the invariance of core engineering frameworks whilst technical progression is observed. This constitutes agreement with the understanding of a professional system of profiles which acts as the stem for social, economic, and technological advancements.

Dual narrow surface lattice resonances in Si/SiO2 nanopillar dimer arrays

Si/SiO2 nanopillar dimer arrays are proposed to form two narrow surface lattice resonances (SLRs). One (named SLR1) mainly comes from the coupling between single Si/SiO2 nanopillar dimers’ electric dipole resonance and arrays’ diffraction waves. Another (named SLR2) mainly comes from the coupling between single Si/SiO2 nanopillar dimers’ magnetic dipole resonance and arrays’ diffraction waves. In the array, Si nanopillar dimers are on SiO2 nanopillar dimers, and SiO2 nanopillar dimers are on a quartz substrate. The simulated results reveal that the two SLRs’ linewidths can be as small as 2.6 nm. However, for the Si/SiO2 nanopillar array without dimers, only one SLR can be formed. Compared to the SLR of the Si/SiO2 nanopillar array, the SLRs’ intensity of the Si/SiO2 nanopillar dimer array is stronger and the SLRs’ linewidth of the Si/SiO2 nanopillar dimer array is smaller. The Si/SiO2 nanopillar dimers’ height and diameter, the gap of dimers, and the arrays’ period are all important to regulate the two SLRs. This work is important to the design of micro–nano photonic devices based on multiple SLRs.

Combined wave emission system based on dual resonance method for airborne transient electromagnetic detection

To improve the detection efficiency of airborne transient electromagnetic method (ATEM) and reduce the times of flight experiments, a dual resonance-based combined wave emission circuit is proposed in this paper, which realizes the combined emission of half-sine wave and triangular wave through the selection of different resonant branches. Based on the operating principle of the proposed emission circuit, the model of second-order resistor-inductor-capacitor equivalent circuit is established. Then, the generation process of the combined wave is analyzed, and the segmentation control method is proposed. Finally, the feasibility and effectiveness of the proposed combined wave emission system are verified by simulation model building and prototype testing, and the results show that the emission current has good quality and high stability. Compared with the traditional emission of single wave current, the combined wave current has the advantages of large magnetic moment of half-sine wave and rich high-frequency components of triangular narrow pulse, which can effectively expand the detection range and improve the measurement efficiency of ATEM.

A Resonant High-Pressure Microsensor Based on the Vertical Dual Resonators With Oil-Filled Isolated Structure

This letter developed a resonant high-pressure microsensor with a measurement range of 30 MPa based on a vertical distribution of dual resonators and an oil-filled structure. More specifically, dual resonators were vertically deployed in an H-cavity and were subjected to compressive and tensile stresses under applied pressures while the sensing unit was surrounded by silicon oil and sealed by a corrugated diaphragm structure and a base house for hydraulic measurements. Microfabrication was conducted to fabricate the microsensor and the pressure sensitivities were quantified as 0.135 kHz/MPa (~2103 ppm/MPa) of Resonator I, −0.085 kHz/MPa (~-1358 ppm/MPa) of Resonator II, and 0.219 kHz/MPa (~3461 ppm/MPa) of the differential output of the dual resonators under 20°C, producing fitting and measurement accuracies of 0.01%FS under a pressure range of 0.11-30 MPa and a temperature range of −10-60°C. This study provided a new perspective in the field of high-pressure measurements in harsh environments with high accuracies and sensitivities.

Terahertz metamaterial using reconfigurable H-shaped resonator with tunable perfect absorption characteristic

A design of H-shaped tunable metamaterial absorber (HTMA) is proposed to show multi-resonance and tunable perfect absorption characteristics. It consists of a reconfigurable H-shaped Al resonator suspended on the bottom Al layer. HTMA shows multi-resonance characteristic that can be actively tuned by reconfiguring the H-shaped resonator. The transverse magnetic (TM) responses can be switched from single perfect absorption resonance at 3.04 THz to dual perfect absorption resonances at 3.22 THz and 4.82 THz. While the transverse electric (TE) responses exhibit triple-resonance with great tunability. The corresponding quality factor (Q-factor) and sensitivity are calculated. The sensitivities are 1.16 THz/RIU, 1.76 THz/RIU, 1.27 THz/RIU, 2.24 THz/RIU, and 2.94 THz/RIU for dual-resonance in TM mode and triple-resonance in TE mode, respectively. In consideration of the above optical characteristics, it can be used for the sensing application when the device is exposed to different surrounding refractive index. These results indicate the potential of the proposed HTMA to be applied in optical gas sensors, biosensors, and polarization switches.

A 53–78 GHz Complementary Push–Push Frequency Doubler With Implicit Dual Resonance for Output Power Combining

This paper presents a millimeter-wave (mmW) frequency doubler based on complementary push-push (CPP) configuration achieving wideband, low-power and high-efficiency operation. Conventional push-push (PP) frequency doublers typically rely on half-wave rectification and suffer from performance compromise between the desired output and the DC current consumed. To mitigate this issue, a simple but effective CPP frequency doubling scheme is proposed to realize full-wave rectification, attaining enhanced output harmonic current and improved fundamental rejection without extra power consumption. At the output, an implicit dual-resonance (IDR) network featuring inherent resonant frequency alignment is employed to efficiently combine the harmonic power generated by the CPP transistors. Implemented in a 65-nm CMOS process and occupying a core area of 0.04 mm2, the proposed frequency doubler prototype measures conversion loss of < 10 dB from 53 to 78.5 GHz at 0-dBm input, while consuming 21.5 mW from a 1-V supply.

Polarization-selective narrow band dual-toroidal-dipole resonances in a symmetry-broken dielectric tetramer metamaterial.

Here we propose a metasurface consisting of symmetry-broken dielectric tetramer arrays, which can generate polarization-selective dual-band toroidal dipole resonances (TDR) with ultra-narrow linewidth in the near-infrared region. We found, by breaking the C4v symmetry of the tetramer arrays, two narrow-band TDRs can be created with the linewidth reaching ∼ 1.5 nm. Multipolar decomposition of scattering power and electromagnetic field distribution calculations confirm the nature of TDRs. A 100% modulation depth in light absorption and selective field confinement has been demonstrated theoretically by simply changing the polarization orientation of the exciting light. Intriguingly, it is also found that absorption responses of TDRs on polarization angle follow the equation of Malus' law in this metasurface. Furthermore, the dual-band toroidal resonances are proposed to sense the birefringence of an anisotropic medium. Such polarization-tunable dual toroidal dipole resonances with ultra-narrow bandwidth offered by this structure may find potential applications in optical switching, storage, polarization detection, and light emitting devices.

Glueless Multiple Input Multiple Output Dielectric Resonator Antenna with Improved Isolation

In this dissemination, a glueless compact dual port dielectric resonator antenna (DRA) is proposed for X-band applications. A prototype has been fabricated with RT Duroid substrate and Eccostock (ϵr = 10)-made DRA. The ring shaped DRA is excited by aperture coupled feeds maintaining symmetry between both the ports. Four cylindrical copper rods with four strips have been used to fix the DRA on the substrate and provide additional mechanical stability. Eight copper strips are used to provide impedance matching and impedance bandwidth (IBW) widening. The measured IBW of dual port DRA is 10.5% (8.05–8.95 GHz) and maximum gain of radiator is 6.2 dBi. The proposed antenna becomes compact when the net volume of DRA is approximately 3.5 cm3 and the volume of the substrate is 2.88 cm3, with a surface area of 36 cm2 and operating in X-band, which finds applications in satellite communication, weather radar, synthetic aperture radar, and telemetry tracking and control.

Dual color infrared photodetector with superconducting metamaterials.

Superconducting photodetection offers a wide spectral coverage ranging from the microwave to X-ray, and in the short wavelength range, single photon sensitivity can be achieved. However, in the longer wavelength infrared region, the system detection efficiency is low due to the lower internal quantum efficiency and weak optical absorption. Here, we utilized the superconducting metamatieral to enhance the light coupling efficiency and reach nearly perfect absorption at dual color infrared wavelengths. Dual color resonances arise from hybridization of local surface plasmon mode of the metamaterial structure and the Fabry-Perot-like cavity mode of metal (Nb)-dielectric (Si)-metamatieral (NbN) tri-layer structure. We demonstrated that, at the working temperature of 8 K slightly below TC ∼8.8 K, this infrared detector exhibits the peak responsivity of 1.2 × 106V/W and 3.2 × 106V/W at two resonant frequencies 36.6 THz and 104 THz, respectively. The peak responsivity is enhanced about ∼8 and ∼22 times, respectively, compared to that of non-resonant frequency (67 THz). Our work provides a way to harvest infrared light efficiently and hence improve the sensitivity of superconducting photodetectors in multispectral infrared range, which may find promising applications in thermal image and gas sensing etc.

The American Pipe Dream: Performance of Drug Addiction, 1890–1940

The American Pipe Dream: Performance of Drug Addiction, 1890–1940

Machine learning assisted hepta band THz metamaterial absorber for biomedical applications

A hepta-band terahertz metamaterial absorber (MMA) with modified dual T-shaped resonators deposited on polyimide is presented for sensing applications. The proposed polarization sensitive MMA is ultra-thin (0.061 λ) and compact (0.21 λ) at its lowest operational frequency, with multiple absorption peaks at 1.89, 4.15, 5.32, 5.84, 7.04, 8.02, and 8.13 THz. The impedance matching theory and electric field distribution are investigated to understand the physical mechanism of hepta-band absorption. The sensing functionality is evaluated using a surrounding medium with a refractive index between 1 and 1.1, resulting in good Quality factor (Q) value of 117. The proposed sensor has the highest sensitivity of 4.72 THz/RIU for glucose detection. Extreme randomized tree (ERT) model is utilized to predict absorptivities for intermediate frequencies with unit cell dimensions, substrate thickness, angle variation, and refractive index values to reduce simulation time. The effectiveness of the ERT model in predicting absorption values is evaluated using the Adjusted R2 score, which is close to 1.0 for nmin = 2, demonstrating the prediction efficiency in various test cases. The experimental results show that 60% of simulation time and resources can be saved by simulating absorber design using the ERT model. The proposed MMA sensor with an ERT model has potential applications in biomedical fields such as bacterial infections, malaria, and other diseases.

Prediction model for multidirectional vortex-induced vibrations of catenary riser in convex/concave and perpendicular flows

This study presents an advanced numerical prediction model based on nonlinear wake oscillators for the investigation of multidirectional vortex-induced vibration (VIV) responses of a long catenary riser depending on the structural curved configuration versus the incoming flow direction. By considering a uniform free-stream flow aligned with the initial curvature plane of the catenary riser in a convex or concave shape, the normal flow velocity component is nonlinearly sheared owing to the spanwise variation of inclination angles. This is different from the perpendicular flow case in which the normal flow velocity is spatially constant. To capture the influence of flow direction on the three-dimensionally coupled cross-flow and in-line VIV, distributed wake oscillators are introduced and applied to simulate the fluctuating hydrodynamic lift and drag forces that account for the important effects of cylinder inclination, variable vortex excitation frequencies, global–local​ displacement relationships, and relative flow-cylinder velocities. The amplified mean drag force and the axial force depending on the tangential flow velocity are also considered. These empirical hydrodynamic effects are nonlinearly coupled with the equations of riser three-dimensional motion, and the overall governing equations are numerically solved to assess the multimode, multi-frequency and multi-degree-of-freedom responses. Validation of the model is carried out for VIV of flexible straight and curved cylinders based on experimental results in the literature. Parametric investigations are performed by varying the incoming flow velocities in perpendicular, convex and concave configurations for a long catenary riser with a low mass-damping ratio. In-plane (horizontal and vertical) and out-of-plane VIV features are presented and discussed in terms of space–time varying amplitudes, drag-amplified shape reconfigurations, oscillation frequencies, lock-in occurrences, dual resonances, orbital motion trajectories, fluid–structure energy transfer, and multimodal contributions. Overall prediction results highlight the influence of the cylinder geometric configuration versus the incoming flow orientation on multidirectional VIV characteristics that should be recognised and incorporated into practical analysis tools.

The acoustic performance of a dual Helmholtz resonators system in the presence of a grazing flow

Helmholtz resonators (HR) are widely used in aero-engine systems for noise reduction. By connecting a pair of HRs in series (neck-cavity-neck-cavity), a dual HRs system is formed. This study investigated the influence of neck length, cavity volume and flow Mach number on the noise attenuation performance of a dual HRs system. A three-dimensional numerical simulation was performed to calculate the transmission loss results. The transmission loss (TL) results indicated that the second neck length can influence the second resonance frequency and TL max. Changing the cavity volume significantly influences the noise attenuation ability under lower flow rate conditions compared to higher flow rate conditions. The flow Mach number had a more significant impact on the first TL peak than on the second TL peak. This study shows the relationship between the geometric parameters, grazing flow and noise attenuation performance of a dual HRs system and could provide guidance in designing suitable dual HRs for aero-engine systems.

High quality factor dual wavelength Fano resonance based on continuous bound states

The predecessor of China Optics was China Optics and Applied Optics Digest, which was founded in 1985. At that time, it was the only retrieval journal in the field of optics in China. At the end of 2008, China Optics and Applied Optics Digest was renamed

A 3D-Printed Encapsulated Dual Wide-Band Dielectric Resonator Antenna With Beam Switching Capability

A 3D-Printed Encapsulated Dual Wide-Band Dielectric Resonator Antenna With Beam Switching Capability