Rectangular Resonator Research Articles

Modified rectangular resonator based 15‐bit chipless radio frequency identification transponder for healthcare and retail applications

In this paper, a compact and fully passive chipless radio frequency identification planar tag is proposed based on a modified rectangular resonator. The tag is having a simple design and is fabricated using a low-cost FR4 substrate and acquires a physical footprint of 50 mm × 30 mm. The novelty of the proposed work describes a single passive tag having a reading distance of 84 cm with a 15-bit coding capacity in a compact profile. A spectral bit capacity of 2.727 bits/GHz is achieved in a wide range of frequencies from 0.5 to 6 GHz. A reference wideband horn antenna is used as the interrogator to study the tag detection procedure having gains of 6.6 and 18.77 dBi at 0.5 and 5.8 GHz respectively. The backscattered tag response is well suited to the measurement characteristic of the reader. The measurements are performed in a bistatic mode and the results confirm the 15-bit coding capacity of the chipless tag using frequency domain analysis with a maximum radar cross section of −15 dBsm. The multi-bit coded tag can be suitable for a wide range of wireless applications, viz. tracking, retailing, identification, and healthcare utilities.

Dual notched conformal patch fed 3-D printed two-port MIMO DRA for ISM band applications

Abstract This article explores and develops a two-port MIMO Dielectric Resonator Antenna. The proposed antenna consists of two rectangular DRAs on the X-axis, fed by a trapezoidal conformal patch on the Y-axis. The proposed antenna may be 3D manufactured using a normal 3D printer and both DRAs are integrated with the substrate to minimise mounting error and improve mechanical strength, which were previously the typical constraints in DRAs. Rectangular Complimentary Split Ring Resonators (R-CSRRs) and Circular Complimentary Split Ring Resonators (C-CSRRs) enable the proposed antenna to be band-notched. The R-CSRRs control the 5–5.75 GHz range, whereas the C-CSRRs control the 4.4–4.8 GHz band, which are the commercial band. By keeping both ports orthogonal, the isolation between them was lowered to less than −15 dB in the operational bands. Later, with the substrate cavity, isolation drops to −19 dB for the operational bands. The suggested antenna is MIMO capable and covers the 3.4 GHz of ISM band (3.4–6.8 GHz). The antenna has a 4 dBi, 3.7 dBi and 6.9 dBi gain in the first, second, and third resonance frequencies. Excellent MIMO capabilities and ease of construction and feeding make this 3D printed antenna suited for the ISM band.

Real-Time Metasurface Sensor for Monitoring Micropoisons in Aqueous Solutions Based on Gold Nanoparticles and Terahertz Spectroscopy.

Proof of concept of a new real-time metasurface sensor for micropoison monitoring in aqueous solutions is proposed in this study. The sensor comprises a perfect absorber metasurface and gold nanoparticle layer on the front side of it. Frequency-domain terahertz spectroscopy system was used to measure the resonance frequency shift due to the presence of the micropoison. The perfect absorber metasurface sensor was fabricated using a double-sided FR4 substrate printed board circuit, which is very inexpensive. A significant increase in the metasurface sensor sensitivity was achieved by adding a gold nanoparticle layer to the gap of the double split rectangular resonator on the front side of the metasurface sensor.

Low‐loss X‐band waveguide bandpass filter based on rectangular resonators

AbstractThis paper presents a procedure for designing and synthesizing a 5th‐order waveguide bandpass filter based on rectangular resonators in X‐band frequency. The designed bandpass filter is implemented in waveguide technology with multiple rectangular cavity resonators. Computerized numerical control (CNC) micro‐machined metallic is used in the waveguide filter structure with an accuracy of 0.2 mm. silver plating has been performed inside the X‐band bandpass filter, which has improved the quality of the response. This low‐loss and high‐power X‐band wideband waveguide filter with center frequency at 9.45 GHz, the bandwidth of 0.9 GHz, the return loss of 18 dB, and the insertion loss of 0.08 dB has been realized.

A Band-Switchable and Tunable THz Metamaterial Based on an Etched Vanadium Dioxide Thin Film

A band-switchable and tunable terahertz (THz) metamaterial based on a vanadium dioxide (VO2) thin film was proposed in the THz frequency regime. The VO2 thin film with a high conductivity change rate and smooth phase transition characteristics was deposited. To obtain band switching characteristics and reduce THz wave loss, the VO2 thin film was etched in the form of a line. Two rectangular C-shaped resonators were configured to face each other, with an etched VO2 thin film line in between. When the VO2 thin film was in the insulator phase, the two resonators individually resonated, and when the VO2 thin film was in the metal phase, they were connected and resonated as one, showing band switching characteristics. According to the state of the VO2 thin film, the fabricated metamaterial resonated at 1.29 THz when the two resonators were electrically separated and resonated at 0.65 THz when the two resonators were electrically connected. In the band-switching process, the THz wave transmission characteristics were continuously tunable. The measurement results of the proposed structure clearly showed that the rectangular C-shaped metamaterial based on the etched VO2 thin film is capable of band switching and continuous transmission control. In the near future, band-switchable and tunable THz metamaterials based on etched VO2 thin films can be employed as key devices in THz wave 6G wireless communication technology.

Acoustic Streaming Induced by Wall Oscillations of a Plane Rectangular Resonator

Acoustic Streaming Induced by Wall Oscillations of a Plane Rectangular Resonator

Numerical Study of Baroclinic Acoustic Streaming Phenomenon for Various Flow Parameters

The article presents a numerical study of the large-amplitude, acoustically-driven streaming flow for different frequencies of the acoustic wave and different temperature gradients between hot and cold surfaces. The geometries studied were mainly two-dimensional rectangular resonators of different lengths, but also one three-dimensional rectangular resonator and one long and narrow channel, representative of a typical U-shaped resistance thermometer. The applied numerical model was based on the Navier–Stokes compressible equations, the ideal gas model, and finite volume discretization. The oscillating wall of the considered geometries was modeled as a dynamically moving boundary of the numerical mesh. The length of the resonators was adjusted to one period of the acoustic wave. The research confirmed that baroclinic acoustic streaming flow was largely independent of frequency, and its intensity increased with the temperature gradient between the hot and cold surface. Interestingly, a slight maximum was observed for some oscillation frequencies. In the case of the long and narrow channel, acoustic streaming manifested itself as a long row of counter-rotating vortices that varied slightly along the channel. 3D calculations showed that a three-dimensional pair of streaming vortices had formed in the resonator. Examination of the flow in selected cross-sections showed that the intensity of streaming gradually decreased as it approached the side walls of the resonator creating a quasi-parabolic profile. The future development of the research will focus on fully 3D calculations and precise identification of the influence of the bounding walls on the streaming flow.

Multibit Coded Passive Hybrid Resonator Based RFID Transponder With Windowing Analysis

This study proposes novel design options for a compact passive transponder that incorporates both stepped impedance resonators (SIR) and rectangular stub resonators in a hybrid approach. The analysis aims to support the progress of chipless radio frequency identification (RFID) technology by overcoming barriers like cost, size, and coding capacity. A step-by-step analysis of the design ensures a 10-bit coding capacity with a physical footprint of 32 mm × 15 mm having -25.66 dBsm of maximum radar cross-section (RCS) response. The same has been analysed at the receiver with a rectangular windowing approach which enhances the coding capacity and security features of the RFID system. Further, this has been analysed with Hamming, Hanning, and Bartlett windows to show the effectiveness of the windowing techniques in RFID coding. The performance of the tag is analysed for different tilt-angles and read-distances to strengthen the detection accuracy. The hybrid resonator (HR) with windowing analysis is a novel approach to enhance the usage of the transponder by improving the coding capacity, information storage capability, and detection performance in various retail and healthcare domains in the RFID industry.

Design of electromagnetic cloak with sequentially connected rectangular split ring resonators for S-band applications

<abstract> <p>An electromagnetic (EM) invisible cloak is designed and analyzed with serially interconnected split ring resonators (SRRs). The cloak consists of an array of a network of split ring resonators which operates at a 3 GHz resonating frequency. The split ring resonators are connected with transmission line and are wrapped around the cylindrical object. Cloak coupled with EM waves gets transferred around the cylindrical object and received to the other side of transmission. Scattering cross section (SCS) is analyzed for both cases, which results in the effect of resonance. The total scattering cross section of the cloaked object is reduced by using SRRs. The simulated and measured results are in great agreement with each other. The transmission-line-connected SRR cloak is useful for S-band applications specifically at 3 GHz resonance.</p> </abstract>

Experimental study of an tunable acoustic phase-shifter

The paper presents the results of a numerical and experimental study of an acoustic phase-shifter based on a chain of rectangular Helmholtz resonators. Phase regulation of the transmitted acoustic wave is made by simultaneously changing the resonators volumes with the stepper motor. As a result of the experiment it was found that the developed acoustic phase-shifter allows to manipulate the wave phase within the range of 0-2π in the frequency range of 2000-2500 Hz. The transmittance factor is not less than 0.7. The phase-shifter can be used as a unit cell of tunable acoustic metasurface. Keywords: acoustics, wave control, phase-shifter, metasurface.

Design and Analysis of Compact 5th Mode Balanced Substrate Integrated Waveguide Band-Pass Filter for 39 GHz

This paper presents a balanced fifth-order Substrate Integrated Waveguide (SIW) band-pass filter operating at 39 GHz. The filter uses the balanced nature of the SIW resonators and the odd-mode property of the TE102 mode. Five rectangular resonators have been used to develop a fifth-order band-pass filter and the couplings between them with the external quality factors have been determined. The filter yields a good response in the KA band of the electromagnetic spectrum. It has a smaller footprint and operates at a higher frequency range compared to other filters with the same technology. The Common-Mode (CM) signal has been effectively suppressed to more than -30 dBs throughout the considered range. The return loss of -30 dBs and an insertion loss of -4 dBs for the Differential-Mode (DM) operation are achieved at the operating frequency of 39 GHz. The half-mode operation of the filter has been also implemented and the results have proven to be satisfactory.

New Optical Method for the Sucrose Solution Measurement Based on Fano Resonance

We propose a new method to determine the concentration of a sucrose solution based on Fano resonance, demonstrate that the [Formula: see text]-shaped resonator and rectangular resonator structures can realize the Fano resonance, observe higher sensitivity up to 2142 nm/RIU, and use the structure to measure the concentration of a sucrose solution. This work shows that the Fano resonance wavelength removed to longer wavelengths as the concentration of the solution increased, and the resolution of solution concentration is [Formula: see text], which can be used for measuring the concentration of solutions other than sucrose. This research is an important first step towards creating the industrial application of photon properties to extend photon polariton applications throughout the infrared.

Sensing Glucose Concentration Using Symmetric Metasurfaces under Oblique Incident Terahertz Waves

In this article, a planar metamaterial sensor designed at terahertz (THz) frequencies is utilized to sense glucose concentration levels that cover hypoglycemia, normal, and hyperglycemia conditions that vary from 54 to 342 mg/dL. The sensor was developed using a symmetric complementary split rectangular resonator at an oblique incidence angle. The resonance frequency shift was used as a measure of the changes in the glucose level of the samples. The increase in the glucose concentration level exhibited clear and noticeable redshifts in the resonance frequency. For instance, a 67.5 GHz redshift has been observed for a concentration level of 54 mg/dL and increased up to 122 GHz for the 342 mg/dL concentration level. Moreover, a high sensitivity level of 75,700 nm/RIU was observed for this design. In the future, the proposed THz sensors may have potential applications in diagnosing hypocalcemia and hyperglycemia cases.

Highly Sensitive Differential Microwave Sensor for Soil Moisture Measurement

This paper presents a highly sensitive differential soil moisture sensor (DSMS) using a microstrip line loaded with triangular two-turn resonator (T2-SR) and complementary of the rectangular two-turn spiral resonator (CR2-SR), simultaneously. Volumetric Water Content (VWC) or permittivity sensing is conducted by loading the T2-SR side with dielectric samples. Two transmission notches are observed for identical loads relating to T2-SR and CR2-SR. The CR2-SR notch at 4.39 GHz is used as a reference for differential permittivity measurement method. Further, the resonance frequency of T2-SR is measured relative to the reference value. Based on this frequency difference, the permittivity of soil is calculated which is related to the soil VWC. Triangular two-turn resonator (T2-SR) resonance frequency changes from 4 to 2.38 GHz when VWC varies 0% to 30%. The sensor’s operation principle is described through circuit model analysis and simulations. To validate the differential sensing concept, prototype of the designed 3-cell DSMS is fabricated and measured. The proposed sensor exhibits frequency shift of 110 MHz for 1% change at the highest soil moisture content (30%) for sandy-type soil. This work proves the differential microwave sensing concept for precision agriculture.

Modified rectangular resonators based multi‐frequency narrow‐band RFID reader antenna

AbstractIn this article, a chipless RFID reader antenna based on a modified rectangular‐resonator is presented. The reader antenna is fabricated and measured to validate multiple narrowband resonance behavior. The measurement results show that the reader antenna can detect 11‐bit multi‐frequency coded chipless tag and depict gains of 4.7 and 5.2 dBi at 0.58 and 2.4 GHz, respectively. The cubic interpolation approach as a signal processing technique is applied at the reader end to eliminate the unnecessary drops at the measurement. Further study of Chu and Mclean's fundamental limit demonstrates that the physical dimensions of the proposed antenna and the radiation characteristics fulfilling the limitations. The multiple narrow‐band responses of the reader antenna can be suitable to detect multi‐bit tags which are of high demand because a multibit tag can be used for multiple frequency applications for hassle‐free wireless environment, viz. tracking, retailing, identification, and healthcare utilities.

A new design of UHF tag antenna for clothing identification using SRR

In this paper, we present a new antenna for radio frequency identification (RFID) tag operating in the Moroccan ultra high frequency (UHF) band around 868 MHz, this antenna is designed on a flexible plastic substrate of relative permittivity 3 and low tangential losses which is 0.002. The proposed tag is designed to identify clothing in supermarkets. The tag antenna has a miniature size of 38 mm in length and 26 mm in width. This miniature size was obtained by using two rectangular split ring resonator (RSRR). The impedance matching of the RFID chip with the antenna was carried out by a double T-matching structure. The antenna is designed, simulated and optimized using computer simulation technology (CST) microwave studio software and good results have been obtained in terms of impedance matching, gain and read range.

Quadruple Band-Notched Compact Monopole UWB Antenna for Wireless Applications

A printed quadruple band-notched ultra-wideband (UWB) antenna characteristic is presented. The designed UWB antenna has a size of 32 mm × 30 mm × 1.6 mm and covers an impedance bandwidth off 2.9–14.5 GHz for the entire frequency band. The entire frequency band maintains voltage standing wave ratio (VSWR) <2, except at WiMAX (3.1–3.6 GHz), WLAN (4.92–6.12 GHz), downlink of X-band for satellite communication systems (7.5–8.4 GHz), and X-band (10.2–11 GHz). By inserting a pair of L-shaped slots into the radiating element, a H-shaped resonator and rectangular split-ring resonators are closely arranged to the microstrip feed-line, alongside the measured impedance bandwidth of 129%. The fabricated antenna radiation pattern and return loss is presented.

Substrate integrated waveguide bandpass filter for short range device application using rectangular open loop resonator

The substrate integrated waveguide (SIW) structure is the candidate for many application in microwave, terahertz and millimeter wave application. It because of SIW structure can integrate with any component in one substrate than others structure. A kind components using SIW structure is a filter component, especialy bandpass filter. This research recommended SIW bandpass filter using rectangular open loop resonator for giving more selectivity of filter. It can be implemented for short range device (SRD) application in frequency region 2.4 - 2.483 GHz. Two types of SIW bandpass filter are proposed. First, SIW bandpass filter is proposed using six rectangular open loop resonators while the second SIW bandpass filter used eight rectangular open loop resonators. The simulation results for two kinds of the recommended rectangular open loop resonators have insertion loss (S<sub>21</sub> parameter) below 2 dB and return loss (S<sub>11</sub> parameter) more than 10 dB. Fabrication of the recommended two kind filters was validated by Vector Network Analyzer. The measurement results for six rectangular open loop resonators have 1.32 dB for S<sub>21</sub> parameter at 2.29 GHz while the S<sub>11</sub> parameter more than 18 dB at 2.26 GHz – 2.32 GHz. While the measurement results has good agreement for eight rectangular open loop resonators. Its have S<sub>21</sub> below 2.2 dB at 2.41 – 2.47 GHz and S<sub>11</sub> 16.27 dB at 2.38 GHz and 11.5 dB at 2.47 GHz.

The effect of resonator shape on air flow in flue organ pipes

The effect of changing the shape of the resonator of a flue organ pipe was studied in a replica of an organ pipe that was printed using transparent media. The pipe was designed so that the rectangular resonator could be replaced by a cylindrical one of the same cross sectional area, and the airflow in the pipe was imaged using high-speed transmission electronic speckle pattern interferometry. The resulting images reveal that there is a fundamental difference in the flow when the resonator shape is altered. Differences in the airflow and sound attributable to the shape of the resonator will be discussed.

Sensitivity-Enhanced Fluidic Glucose Sensor Based on a Microwave Resonator Coupled With an Interferometric System for Noninvasive and Continuous Detection.

In this paper, a microwave fluidic glucose sensor based on a microwave resonator coupled with an interferometric system is proposed for sensitivity enhancement. The proposed glucose sensor consists of two parts: a sensing part and a sensitivity enhancement part. The former is composed of a rectangular complementary split ring resonator (CSRR), and the latter is composed of a variable attenuator, a variable phase shifter, two hybrid couplers, and an RF power detector. Because the variation in the electrical properties, which is utilized in the microwave detection scheme, with glucose concentration over the possible concentration range in the human body is very small, improvement of the sensitivity is critical for practical use. Thus, the effective sensing area of the rectangular CSRR is determined by considering the electric field distribution. In addition, magnitude and phase conditions for the effective sensitivity enhancement are derived from a mathematical analysis of the proposed interferometric system. In the present experiment, aimed at demonstrating the detection performance as a function of the glucose concentration in the range of 0 mg/dL to 400 mg/dL, the sensitivity is significantly improved by 48 times by applying the derived conditions for effective sensitivity enhancement. Furthermore, the accuracy of the proposed glucose sensor for glucose concentrations at a step of 100 mg/dL is verified by the Clarke error grid. Based on the measurement results, the proposed glucose sensor is demonstrated to be applicable to noninvasive and continuous monitoring in practical environments.