Dual Resonant Structure Research Articles

Partial Discharge Wideband Full-Band High-Gain Resonant Cavity UHF Sensor Research.

To meet the real demand for broadband full-band high-gain antenna sensors in the process of partial discharge (PD) Ultra-High frequency (UHF) detection test and online monitoring of power equipment, this paper builds a resonant cavity monopole UHF antenna sensor based on Fabry-Perot resonant cavity antenna technology, conducts the sensor Voltage Standing Wave Ratio (VSWR) optimization study using curved flow technology, conducts the sensor gain optimization study using slot dual resonant structure, and, finally, tests the sensor performance using the built PD detection test platform. The resonant cavity monopole antenna exhibits outstanding VSWR performance in the frequency range of 0.37 GHz-3 GHz, according to simulation and test data: the average gain in the frequency range of 0.3 GHz-3 GHz is 4.92 dBi, and the highest gain at the primary resonant frequency of 1.0 GHz is 7.16 dBi, with good radiation performance over the whole frequency spectrum. The electromagnetic pulse signal sensed by the UHF sensor developed in this paper can demonstrate the energy spectrum distribution characteristics of PD radiation electromagnetic wave signal more comprehensively, laying a firm technical foundation for thoroughly understanding the electromagnetic wave radiation characteristics of various types of PD insulation defects of various power equipment and the selection of a specific direction for its supporting optimization.

A Low Voltage Stress PFC Rectifier Based on Nonoverlapping Strategy Using Resonant Switched-Capacitor Converter

In order to break limited step-down ratio range and poor regulation capacity in the conventional resonant switched-capacitor converters for rectifier application, a single-stage ac/dc rectifier based on the dual-resonance switched-capacitor converter is proposed in this article. Through utilizing a dual-resonant structure and nonoverlapping strategy to realize wide continuous voltage gain of the proposed converter, high power factor (PF) and low total harmonic distortion (THD) based on the narrow dead zone are guaranteed by operating at high step-down conversion ratio in this converter topology. Moreover, the voltage gain is concentrated between resonant frequency and double resonant frequency to achieve a narrow switching frequency range for rectifier application. Furthermore, operating at flat voltage stress curves to obtain low voltage stress character. Comprehensive mode analysis, input PF and THD, and stress analysis are given, and analysis results indicate that the proposed power factor correction converter can work with soft turn <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> and zero-current turn <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">off</small> ; high efficiency is realized. Finally, an experimental prototype with 85–130 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ac</sub> input and 47 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</sub> /44 W output is built and tested for verifying the operation modes and PFC performance, and the comparison between different rectifiers and the proposed one is provided.

Design of a novel compact highly selective wideband bandstop RF filter using dual path lossy resonator for next generation applications.

This article presents the design of a wideband bandstop RF filter intending to improve selectivity and compactness. Conventional bandstop filter topology with finite unloaded quality factor produces degraded bandstop filter performance due to dissipation loss. In the proposed filter design, a novel dual path Capacitive Coupled Step Impedance Resonator (CCSIR) structure is used to obtain an infinite stopband attenuation. A uniform impedance resonator is used in Path 1, whereas Path 2 contains a resonator that is twice coupled to the transmission lines. The electrical length of both paths is chosen to be out of phase, resulting in a high rejection level at higher frequencies. It has been analyzed that the selectivity can be improved by increasing the order of the dual coupled step impedance resonator. The proposed design produces a wideband BSF centered at 5.25 GHz with a high rejection level of 104.3 dB and fractional bandwidth of 58.5%. The results have demonstrated that the resonant frequencies are regulated by varying the electrical length of CCSIR. Moreover, it has been realized that out of phase signal cancellation due to the dual path is involved in producing the finite frequency transmission poles, which further enhances the filter selectivity. However, the same electrical performance can only be achieved from coaxial cavities and waveguides due to the high-quality factor. The proposed topology is fabricated and measured on a high-frequency microstrip substrate having a low-quality factor with a compact output and better electrical performance compared to coaxial cavities or waveguides. Due to its high electrical performance and small size, the proposed BSF is appropriate for 4G and 5G (FR1) applications. The measurement shows good concurrence with the full-wave EM simulated results. The fabricated prototype of third order BSF has a compact size of (0.7 × 0.77)λg at 5.25 GHz.

Compact Dual Bandpass Filter Using Dual-Split Ring Resonator for 5G Upper Microwave Flexible Use Services

A novel, compact dual bandpass filter design is proposed for 5G upper microwave flexible use services. To realize the proposed design, a dual split-ring resonator structure coupled to the microstrip transmission line is used. The output responses have been validated using vector network analyzer N5222A. The measured filter records a frequency range of 23.8 GHz–25.98 GHz for the first passband and 28.05 GHz–28.7 GHz for the second band, with fractional bandwidths of 8.8% and 2.2%, respectively. The minimum insertion loss is observed to be 4.2 dB using microstrip technology, even at higher frequencies. The proposed design occupies the area of 0.4 λg×0.27 λg, where λg is guided wavelength at the lower band central frequency. Simulated and measured results are approximately compatible with each other. The proposed design is useful for fixed satellite service earth stations, terrestrial wireless operations, and 5G mobile communications applications.

Dual Resonant Wearable Metamaterial for Medical Applications

A dual band textile wearable metamaterial is designed and fabricated as a ground plane for dual resonant wearable antennas at the Industrial-Scientific-Medical (ISM) frequency band for the applications of RadioFrequency-Identification (RFID) and Wireless-Local-Area-Network (WLAN). The proposed Metamaterial has zero-degree reflection coefficient phases at 0.9 and 2.4 GHz to reflect the backward radiations of the antenna incident waves upward, thus maximizing the gain out of the body and minimizing the risk of exposure into it. The radiation patterns, front-to-back ratio of the antenna with and without metamaterial and the reflection coefficient S11 of the dual resonant structure on different body loadings are investigated. The effect of bending on the performance of the proposed integrated structure has been measured. The limitation of the interacted electromagnetic waves with a heterogeneous voxel model has been analyzed using the specific energy absorption rate (SAR). The measured S11 values of the proposed structure on the human hand have showed an excellent agreement with the simulation over inhomogeneous phantom. The proposed structure has exhibited insignificant shift in resonant frequencies and return loss values at different bending angles. The proposed dual band metamaterial-backed antenna revealed a gain of 6.5 dBi, a front-to-back ratio of 12.5 dB and 10g-based SAR results less by 94% than the metallic reflector-backed antenna when both are placed over the same hand voxel model.

An Improvement of SNR for Simultaneously Wireless Power and Data Transfer System with Full-Duplex Communication Mode

The power interference is always inevitable in the simultaneous wireless power and data transfer (SWPDT) system resulting in the lower signal to noise rate (SNR) and may cause the failure of communication. Besides, the interference between bidirectional data source is also the problem during the full-duplex communication. To solve these problems, in this article, an improvement of SNR for SWPDT system with full-duplex communication mode is proposed. In the power transfer channel, the double-sided LCCL compensation topology is selected due to its good performance of blocking the power interference on data transmission. Besides, the constant current characteristic of primary coil could guarantee the stability of power transmission. In the data transfer channel, a novel data transmission based on the dual-resonant structure is proposed to suppress the ipsilateral interference, and the full-duplex communication is achieved by two different frequencies. An optimization method of power and data transfer channel to improve SNR further is proposed after the analysis on interferences of power transmission and ipsilateral data source. Finally, the feasibility of proposed topology and the correctness of the parameter design method are verified by the simulation and experimental results.

Compact Dual-Band Rectenna Based on Dual-Mode Metal-Rimmed Antenna

This paper proposes the design of a dual-band integrated rectenna. The rectenna has compact size of 0.4 × 0.3 × 0.25 cm3 and operates at 925 MHz and 2450 MHz bands. In general, the rectenna consists of two main parts, the metal-rimmed dual-band antenna used for harvesting the radio frequency (RF) signals from the environment and the rectifier circuit to convert these receiving powers to the direct current (DC). Because of the dual resonant structure of the antenna, the rectifier circuit can be optimized in terms of size and the frequency bandwidth, while the conversion efficiencies are always obtained 60% at the RF input power −2.5 dBm and −1 dBm for the lower band and the higher band, respectively. Measured results show that the metal-rimmed antenna exhibits −10 dB reflection coefficient in both desired frequency bands. Moreover, the antenna achieves 47% and 89% of total efficiency respectively at 925 MHz and 2450 MHz, which confirms that the proposed rectenna is well applicable in most of the miniaturized wireless sensor networks and IoT systems.

Dual-Resonator MEMS Magnetometer Based on Self-Clocking Sigma-Delta Modulation

This paper presents the design and experimental evaluation of a micromachined Lorentz force magnetometer with a dual-resonator structure, interfaced with an electromechanical sigma-delta modulation (EM- $\Sigma \Delta {\text {M}}$ ) force rebalancing control loop. The magnetometer chip comprises a matched pair of resonators on the same silicon die. The closed-loop control circuit relies on a self-oscillating architecture; the frequency of which is determined by first resonator. It is used to generate a drive current injected to the second resonator, and also generates all internal circuit clocks based on a self-clocking scheme. System level simulation indicate a signal-to-noise ratio (SNR) larger than 100dB in a bandwidth of 64Hz with a 10mT, 32Hz magnetic field input ( ${B}$ ). The system was implemented in hardware based on a dual quantization technique, which has the advantage of reduced quantization error of multi-bit quantization in a single sigma-delta modulator. Experimental results demonstrate that proposed dual-resonator magnetometer achieved a 7-fold improvement in bias instability (increasing the averaging time to reach the bias instability from 1s to 8s) and the bandwidth (BW) is increased to ~80Hz, 16-fold higher compared to an open-loop magnetometer with a single resonator. With a 1mA bias current, the output noise is less than $1\mu \text{T}/\surd $ Hz for the z-axis magnetic field.

Bandwidth Enhancement Technique for Broadside Tri-Modal Patch Antenna

A technique for enhancing the bandwidth of a broadside tri-modal patch antenna is described. The key idea of the technique is to incorporate a dual-resonance structure into the broadside tri-modal patch geometry. By increasing one edge of the tri-modal patch while decreasing its size at the opposite edge, the resulting structure can be viewed as two superimposed Y-shaped structures of different resonant frequencies. This intuition is confirmed using characteristic mode analysis (CMA). Furthermore, guided by CMA, further modifications enable two sets of resonant modes to be tuned for increasing the bandwidth of the tri-modal patch antenna. Importantly, the proposed bandwidth enhancement technique does not affect the desired broadside radiation patterns significantly. Therefore, it can be utilized to modify the tri-modal patch antenna without degrading its potential for massive MIMO array application. Measurement results show that the technique enhances the 10 dB impedance bandwidth from 4.3% to 19.7% with the largest antenna dimension of $0.48{\lambda _{c}}$ , where ${\lambda _{c}}$ is the wavelength in air at the center frequency. The design example of the proposed technique is able to cover widely used 3 GHz bands in 5G communication systems and its potential usage in massive MIMO arrays is demonstrated.

Simultaneous Wireless Power and Bidirectional Information Transmission With a Single-Coil, Dual-Resonant Structure

Simultaneous wireless power and information transmission constitute an essential topic in the area of wireless power transfer (WPT) systems. In this paper, a dual-channel transmission model is constructed for integrating bidirectional data communication into a WPT system based on a single-coil, dual-resonant structure. Formulas for the Q value at the energy transmission channel, the bandwidth at the signal transmission channel, and the bidirectional crosstalk between the energy and signal transmission channels are deduced. The design methods for circuit parameters are analyzed with the aim of balancing the transmission power, signal transmission bandwidth, and crosstalk. Additionally, bidirectional communication transmission abilities with different coil misalignments are analyzed. Finally, three sets of different simulation models and an experimental platform are constructed to verify the proposed circuit design method and to implement an experimental system that transfers 354 W and 19.2 kbps with an air gap of 100 cm.

Design of Dual-Band Frequency-Selective Rasorber

A novel frequency-selective rasorber (FSR) with dual-band transmission and wideband absorption property is proposed in this letter. The FSR is a two-layer structure composed of a lossy resistive sheet at the top and a lossless bandpass frequency-selective surface (FSS) at the bottom, separated by an air spacer. The element of the resistive sheet is a lumped-resistor-loaded metallic dipole with a dual-resonance structure inserted in the center. The dual-resonance structure is realized by three different series LC structures in parallel, based on the Foster reactance theorem. There are two impedance poles between the three impedance zeros of the series LC circuits, where two transparent windows can be obtained for the lossy resistive sheet. The bandpass FSS is a simple dual-band FSS by etching two slots with different shapes and dimensions in a metallic plane. The FSR has realized two transmission bands at 7.7 and 12.6 GHz, and the band with | S 11| < −10 dB is 3.7–11.1 GHz. The design has been validated by full-wave simulation and experimental measurement.

Dual MEMS Resonator Structure for Temperature Sensor Applications

This paper reports an acoustic microelectromechanical system (MEMS) resonator structure that features dual-resonant response at 180 and 500 MHz. The MEMS structure uses aluminum nitride as acoustic layer and electrodes with dual design that provide dual-resonance behavior. Each resonant mode operates at the first symmetrical Lamb-wave mode (S0). Due to the large frequency separation between modes, device exhibits differentiated temperature coefficient of frequency) for each mode, which makes this structure suitable for thermometric beat frequency sensing. Reported devices are thus capable to multiply the 20-ppm/°C thermal sensitivity of the individual sensors by one order of magnitude, up to −334 ppm/°C for the thermometric beat frequency sensor.

Multilayered Inclusions in Locally Resonant Metamaterials: Two-Dimensional Versus Three-Dimensional Modeling

Locally resonant metamaterials (LRMs) controlling low-frequency waves due to resonant scattering are usually characterized by narrow band gaps (BGs) and a poor wave filtering performance. To remedy this shortcoming, multiresonant metamaterial structures with closely located BGs have been proposed and widely studied. However, the analysis is generally limited to two-dimensional (2D) structures neglecting the finite height of any real resonator. The aim of this paper is the comparison of the wave dispersion for two- and three-dimensional (3D) metamaterial models and evaluation of the applicability ranges of 2D results. Numerical study reveals that dual-resonant structures with cylindrical inclusions possess only a single (compared to two in the 2D case) BG for certain height-to-width ratios. In contrast, the wave dispersion in metamaterials with multiple spherical resonators can be accurately evaluated using a 2D approximation, enabling a significant simplification of resource-consuming 3D models.

Electrostatic energy harvesting device with dual resonant structure for wideband random vibration sources at low frequency.

In this paper, we present design and test of a broadband electrostatic energy harvester with a dual resonant structure, which consists of two cantilever-mass subsystems each with a mass attached at the free edge of a cantilever. Comparing to traditional devices with single resonant frequency, the proposed device with dual resonant structure can resonate at two frequencies. Furthermore, when one of the cantilever-masses is oscillating at resonance, the vibration amplitude is large enough to make it collide with the other mass, which provides strong mechanical coupling between the two subsystems. Therefore, this device can harvest a decent power output from vibration sources at a broad frequency range. During the measurement, continuous power output up to 6.2-9.8 μW can be achieved under external vibration amplitude of 9.3 m/s2 at a frequency range from 36.3 Hz to 48.3 Hz, which means the bandwidth of the device is about 30% of the central frequency. The broad bandwidth of the device provides a promising application for energy harvesting from the scenarios with random vibration sources. The experimental results indicate that with the dual resonant structure, the vibration-to-electricity energy conversion efficiency can be improved by 97% when an external random vibration with a low frequency filter is applied.

Dual resonant structure for energy harvesting from random vibration sources at low frequency

We introduce a design with dual resonant structure which can harvest energy from random vibration sources at low frequency range. The dual resonant structure consists of two spring-mass subsystems with different frequency responses, which exhibit strong coupling and broad bandwidth when the two masses collide with each other. Experiments with piezoelectric elements show that the energy harvesting device with dual resonant structure can generate higher power output than the sum of the two separate devices from random vibration sources.

Enhanced plasmonic band-pass filter with symmetric dual side-coupled nanodisk resonators

A plasmonic band-pass filter with symmetric dual side-coupled nanodisk resonators in metal-insulator-metal system is proposed. Compared with the single side-coupled nanodisk resonator structure, the new structure has better transmission response due to the superposition of the outgoing-wave fields' amplitudes of the two resonators. The accurate transmission expression is provided based on the temporal coupled mode theory, and the dynamic transmission response is studied by finite difference time domain method. It is indicated that the transmission characteristics of the symmetric dual nanodisk resonator structure is sensitive to the refractive index of the nanodisk resonators and geometrical parameters. Moreover, the optimum transmission at the wavelengths of 1310 nm and 1550 nm can reach up to 90.8% and 86.2%, with the relative full width at half-maximum of 35 nm and 42 nm, which are better than the results reported in recent literatures. The filter we proposed has important potential applications on plasmonic nanostructures in highly integrated optical circuits and optical information processing.

Analysis and design of a cross dipole nanoantenna for fluorescence-sensing applications

This paper introduces the novel concept of a cross dipole nanoantenna for use in fluorescence based sensing applications. The dual-arm nature of the cross nanoantenna allows a dual resonant structure to be designed such that the shorter arm resonates with the pump wavelength and the longer arm with the emission wavelength. This is expected to further enhance emission from any fluorescent molecule that can couple to both nanoantenna arms when compared with a singly resonant structure. The paper uses the finite-difference time-domain method to first analyze the two-arm nanoantenna case and then shows how intensity enhancement depends on the antenna geometry and tapering of arms in the antenna gap. The results show that smaller gap sizes always produce larger enhancement compared with lightning rod effects due to tapering. A four-arm cross nanoantenna is then studied, highlighting differences from the two-arm case. Finally, the effect of a diagonally aligned molecule transiting the central gap region is studied. The results show that two hotspots occur on either side of the central gap region when the molecule is aligned perpendicular to the transit direction and only a single central hotspot occurs when the alignment is parallel to the transit direction.

Design and Implementation of a Digitally Tunable Tracking Preselected Filter for Ultra Short Wave Receiver

Design of a digitally tunable tracking preselected filter for improving anti-interference for Ultra Short Wave receiver front-end is proposed in this paper and the characteristics of the preselected filter circuit are analyzed. Then we mainly discuss an inductor-coupled dual resonant structure with better selectivity and anti-jamming and its implementation. Finally, test results are provided, shown the specifications of the circuit are in great agreement with the simulation and design requirements.

대역 통과 도파관 여파기 설계를 위한 이중 공진 아이리스 해석

This paper deals with transmission characteristics of a new dual resonant structure for designing waveguide band-pass filter. The structure which has a pass-band between two adjacent stop-bands in a single body consists of circular ridged aperture and four armed conducting patch. The dual resonant behavior of the structure can be represented by a combination of LC series and parallel resonant circuits. Also these resonant properties can be easily controlled by varying the geometry of the aperture and four armed conducting patch. Actually, the structure is fabricated on the microstrip substrate by use of etching technique so that it is formed an iris type resonator which can be easily put into the transverse plane of the waveguide. We use WR-90 standard waveguide, adapters, and VNA(vector network analyzer) to measure the resonant characteristics of the structure. It is very useful to design and to improve the cutoff skirts characteristics in the waveguide band-pass filter design area.

Optical Noise Analysis in Dual-Resonator Structural Micro-Optic Gyro

A novel micro resonator optic gyroscope comprising a dual-resonator structure is proposed. This design radically eliminates the noise induced by Rayleigh backscattering, the Kerr effect and polarization coupling. The configuration of the micro optic gyroscope (MOG) is given and described. Three methods are applied to suppress the optical noises in the system and to theoretically analyze the performance improvement. Experiments are carried out on both dual-resonator and single-resonator MOGs, which show the resonance depth improvement from 0.7477 to 0.9173 in the present MOG dual-resonator configuration.