Rectangular Resonator Research Articles

Synthesis Design of In-Line Pseudoelliptic SISL Bandpass Filter Employing Non-Resonating Mode in Low-Loss Patch Resonators

This paper presents a novel type of patch resonator suitable for the design of high selectivity in-line pseudoelliptic bandpass filters (BPFs) based on a substrate-integrated suspended line (SISL) platform. The proposed structure is a rectangular patch resonator that allows the propagation of the fundamental mode and high order modes. By controlling the position of input and output feedlines, the proposed resonators can provide both a reflection and a transmission zero simultaneously. Thus, a pole-zero pair can be produced (behaving as a singlet). The position of poles and zeros can be fully controlled by varying the position and orientation of the feeding lines. To verify the proposed concept, a detailed study about the behavior of the patch singlet and a validated third-order filter BPF with three TZs ( canonical BPF) located in the lower and upper passband is presented in this brief. The measured results exhibit an extended stopband with rejection better than 58 dB in the lower passband and 40 dB in the upper passband. The tested return losses and insertion loss are better than -15.7 dB and 1.31 dB, respectively.

Multifunctional optical logic device based on nanoscale rectangular ring resonator

Integrated optical logic devices are essential building blocks for implementing all-optical arithmetic and logic unit. In this paper, an ultra-compact multifunctional optical logic device consisting of a rectangular ring resonator coupled with two parallel metal–insulator–metal waveguides is presented. The transmission characteristics of the structure are analyzed in detail via temporal coupled-mode theory. The finite-difference time-domain simulation results reveal that multiple logic functions can be implemented with the aid of the wavelength division multiplexing technique at different output ports. Specifically, all seven basic types of logic gates, half-adder, half-subtractor, and 2*4 decoder can be implemented by monitoring the transmission of through and drop ports at different wavelengths. More importantly, among these functions, six logic gates (OR, XNOR, NAND, NOR, XOR, and AND) and half-adder functions can be performed simultaneously; the NOT logic operation is performed with controllable output ports and selectable working wavelengths; the half-subtractor and 2*4 decoder functions can be operated simultaneously. The proposed logic device is characterized by a small area overhead, multifunctionality, fast response time, and ultrahigh-speed information processing. It may potentially be applied in on-chip universal and parallel photonic computing units.

Scale-Dependent Generalized Thermoelastic Damping in Vibrations of Small-Sized Rectangular Plate Resonators by Considering Three-Dimensional Heat Conduction

Given that thermoelastic damping (TED) is one of the main causes of energy dissipation in miniaturized structures, calculation of its exact amount is of particular importance in the design of such elements. Considering three-dimensional (3D) heat transfer along with the scale effect on both mechanical and thermal areas is one of the decisive factors in the more rigorous modeling of TED in small-sized resonators. This paper exploits the modified couple stress theory (MCST) and dual-phase-lag (DPL) heat conduction model to establish an analytical TED relation for rectangular micro/nanoplate resonators with 3D heat conduction. At the start, the non-Fourier heat equation corresponding to 3D DPL model is derived. Then, the solution of temperature distribution is determined by employing infinite trigonometric series. Moreover, the scale-dependent frequency of the system is presented in the context of MCST. Eventually, with the help of entropy generation (EG) method, an analytical TED expression considering 3D heat conduction is established. The precision of the presented solution is examined by comparing it with a simpler model available in the literature. By choosing two common types of boundary conditions, i.e. fully-clamped (CCCC) and fully-simply (SSSS) supported plates, the influence of various factors on TED changes is comprehensively investigated in simulation section. According to the outcomes, in plates with a lower ratio of length and width to thickness, the dimension considered for heat conduction model has a noticeable impact on the variations of TED.

The mathematical model of the process of combined drying of commercial grain in con-veyor-type installations

The article discusses the results of the development of a model of combined microwave-convective drying of grain products in installations where the product moves inside the working chamber, alternately reaching the minima and maxima of exposure to the electromagnetic field of the microwave range. In the course of research, it was found that it is rational for these purposes to use a working chamber made in the form of a rectangular resonator. The developed mathematical model makes it possible to perform technical calculations for conveyor–type installations - for example, for drum and shaft grain dryers, where the product moves horizontally. Due to the large number of metal structures inside the drying chambers, it is proposed to implement the working chamber as a separate unit that stimulates the release of moisture to the surface of the product.

A nano-refractive index sensor based on a MIM waveguide with a semicircular ring rectangular resonator

This paper proposes a novel nano-sensor structure consisting of the metal-insulator-metal (MIM) waveguide with two rectangular baffles and a semicircular ring rectangular resonator (SRRR). The sensor's transmission characteristics are investigated using the finite-difference time-domain (FDTD) method. The results show that the transmission spectrum of the sensor exhibits the Fano resonance shape. The influences of refractive index and structural parameters on transmission characteristics are systematically investigated. The maximum sensitivity (S) of the sensor can get up to 2560 nm/RIU (refractive index unit), and the figure of merit (FOM) is 1080. In addition, the potential application of the structure in temperature sensing is explored with a sensitivity of 0.87 nm/°C. The proposed structure has promising applications in nanoscale optical sensing.

Copper micromachined WR‐2.2 band waveguide and bandpass filter

AbstractThis paper presents a WR‐2.2 band (330–500 GHz) waveguide with E‐plane bends and a waveguide bandpass filter. A micro‐metal additive manufacturing technology employs copper to process these devices. This technology includes several micromachining processes, which can produce integrated, miniaturized, and complex three‐dimensional metal microstructures when meeting the process constraints. To successfully apply this technology to the fabrication of terahertz waveguide devices, many design details are considered. First, the E‐plane bent transition structures in the waveguide overcome size limitations imposed by the manufacturing process, allowing for accurate measurement using standard waveguide interfaces. Second, the rectangular resonators compose the fifth‐order waveguide bandpass filter spanning 20 GHz with a center frequency of 380 GHz. Given that the excess photoresist needs to be removed, some release holes are designed in the proper positions of the filter. Third, to increase the uniformity of the device layout and improve the machining quality in the electroforming process, a lot of rectangular holes are arranged around the device. By adopting a meticulous and novel design method in accordance with the process advantages and limitations, the fabrication accuracy of the device size is greatly increased. The integrated filter with exceptional performance is obtained. The measured average insertion loss within the passband is better than 1.2 dB, and the return loss exceeds 15 dB. Additionally, the filter demonstrates a center frequency offset of approximately 0.5%. Good consistency between simulation and measurement shows the validity of design and fabrication.

Influence of the Electrical Characteristics of Pulsed Microwave Magnetron Power Supply on the Conditions for Plasma Formation in the Vacuum Chamber of Resonator-Type Plasmatron

The paper presents the research results of the influence of the electrical characteristics of a pulsed microwave magnetron power supply on the microwave discharge generation conditions, determined by the operating mode of the generating system as a whole. Plasma was formed in a vacuumized reaction-discharge volume located inside a rectangular resonator chamber. Depending on the operating modes of the microwave magnetron power supply, studies have been conducted for three modes of microwave discharge plasma generation: pulsed mode with a duty factor S ≈ 2; pulsed mode with a duty factor S ≈ 1.15; continuous mode. Probe measurements of the microwave power in the microwave discharge plasma volume and its local conductivity have been carried out. The paper presents the dependence of the power of microwave energy in the central area of the reaction-discharge quartz chamber of a microwave plasmotron on the amount of power consumed by the microwave magnetron, as well as the distribution of the electrical component of the microwave discharge plasma along the length and cross-sectional plane of the working volume. It has been established that for all studied modes of operation of the power source, with an increase in the power consumption of the microwave generator system, an increase in the microwave power recorded in the central region of the plasma discharge is characteristic. The continuous generation mode is characterized by a decrease in the uneven distribution of electromagnetic energy along the axis of the discharge chamber. It is shown that the transition from a pulsed to a continuous mode of microwave plasma discharge generation at the same level of power consumption by the generating system is characterized by a decrease in the value of the registered microwave power in the microwave discharge plasma volume and an increase in its local conductivity in particular areas of the reaction-discharge volume.

Broadband Linear Polarization Converter Based on Slot-Line Loaded Structure for Pre-Determined Notched Band

This brief proposes a broadband linear polarization converter with pre-determined notched band. By loading a H-shaped slot line on the basis of the rectangular resonator, a pair of resonator modes as well as pre-determined polarization conversion zeros can be additionally allocated inside the band, thereby realizing broadband and band-notch characteristics, simultaneously. The multi-mode resonant mechanism to realize broadband and the conversion zero control principle for notched band are analyzed in detail. Finally, a notch-band broadband linear polarization converter is designed and fabricated, and the simulated and measured results are agreed well with each other. As the main advantage, the proposed multi-mode resonant structure realizing the notched band can achieve flexible isolation band design while hardly affecting the broadband filtering characteristics, and is especially suitable for pre-determined spectrum windows of broadband electromagnetic control devices.

A miniaturized aperture‐coupled 4 × 4 MIMO array SIW antenna at K band

AbstractA planar miniaturized rectangular substrate integrated waveguide (SIW) cavity resonator with an array of patches is presented, which enhances the overall gain of antenna at the K band. The aperture‐coupled feeding is provided from SIW rectangular cavity resonator to reduce radiation losses as in microstrip feeding at a higher frequency. The resonating fields from the cavity excite an array of patches on the substrate. This is further replicated uniformly to design a 4 × 4 element multiple input multiple output (MIMO) antenna. The overall antenna dimension is 2λ × 3.1λ × 0.07λ, where λ is the operating wavelength. The compact structure configuration provides a high peak gain of 13.98 dBi resonating at 19.97 GHz in a broadside direction. An isolation of −17.53 dB is achieved by inserting metal pins. The envelope correlation coefficient of 0.0001 and total active reflection coefficient of −10 dB show characteristics of a high‐performing MIMO antenna. The antenna structure is simulated using HFSS ver. 2022, measured using Anritsu Vector Network Analyzer and Anechoic Chamber, the simulated and measured results are in good concurrence. The antenna is suitable for satellite communication, short‐range wireless applications in IoT, and radar.

THz wave Mux/DeMux operation using bearded-type topological photonic crystal waveguide structure

Abstract Terahertz (THz)wave wireless communication technologies have been developed to increase transmission capacity in 6G communications. Although the realization of integrated waveguides in THz wave transmitters and receivers is essential, bending loss in THz waveguides is important as well. This study investigated a THz waveguide based on a valley photonic crystal (VPC) structure. We numerically investigated a THz waveguide with sharp bending and Mux/DeMux filters based on the oblique rectangular resonator of a bearded-type VPC waveguide.

Higher-Frequency Permeability Measurement by Harmonic Resonance Cavity Perturbation Method

A new combination of electric field antenna and coupling hole plates are introduced to extend the measurable frequency range of rectangular waveguide type harmonic resonator to evaluate complex relative permeability of magnetic composites by perturbation method from 18 GHz to 38 GHz (K/Ka-band). The noise suppression performance parameter ωμ”=2πfμ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> μ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</sub> ” [kΩ/m] is useful to estimate the performance of magnetic powder composite sheets especially beyond 10 GHz range where relative permeability is as small as 0-2. The ωμ” exhibited the maximum of 166 kΩ/m at 27 GHz for a carbonyl iron powder composite sheet, and as high as 510 at 38 GHz for Sendust sheet. These values meet ωμ”≥100 kΩ/m criteria that some commercially available noise suppression sheets exhibit in their recommended frequency range. These performance match Sub-6 GHz band and 28 GHz band used for 5G telecommunication equipment.

Design and Analysis of Frequency Reconfigurable Antenna Loaded Complimentary Split Ring Resonator for Wireless Applications

This paper presents a multi-band reconfigurable antenna, circular patch antenna loaded with combination of rectangular and infinity shape complementary split ring resonator (CSRR). Four slots used for connecting the rectangular with infinity CSRR, where the four PIN diodes loaded in order to achieve reconfigurability. The circular patch has printed in Roger RT/5880 substrate having a dielectric constant of 2.2 within a size 37.35x34.35x1.57. Extraction of permittivity negative of the CSRR is discussed in detail. The proposed antenna can be used in modern and mobile communication devices.

Design of a highly sensitive cascaded rectangular ring resonator embedded with gold nanorods and gratings for multipurpose application

This study introduces a sensor consisting of a metal-insulator-metal (MIM) structure, having an integration of gold nanorods and gratings, to perform various functions including sensing refractive index, detecting blood components, monitoring temperature, and measuring magnetic fields. The sensor's spectral properties are studied analytically in the MIR region implementing finite element method. Furthermore, the potential in the RI sensing is extensively examined by modulating the geometrical parameters, ultimately establishing a direct relationship with the transmittance profile. Following computational experiments, the best possible configuration exhibits the maximum sensitivity of 6118.685 nm/RIU. This research shows the biosensing applications by the detection of near-infrared and visible blood components such RBC, Hb, WBC, plasma, and water with a high sensitivity of 3185.05 nm/RIU. Moreover, ethanol is employed to evaluate the proffered sensor's temperature sensing feature and a maximum sensitivity 1.18 nm/°C was attained. Furthermore, this sensor can be used for magnetic field detection as it shows a high magnetic field sensitivity of 354.66 pm/Oe. The structural model is simple. Besides, this design has the potential to serve as a substitute for sensors that rely on silver. It is chemically stable and performs well in refractive index measurement, biosensing, temperature sensing and magnetic field detection.

Measurement of complex dielectric permittivity of medium and low loss materials at 36.624 GHz and 52.263 GHz using a single iris rectangular cavity resonator

Measurement of complex dielectric permittivity of medium and low loss materials at 36.624 GHz and 52.263 GHz using a single iris rectangular cavity resonator

High-performance plasmonic graphene-based multiplexer/demultiplexer

This paper proposes the use of two innovative single-mode plasmonic resonator-based filters to design a two-channel multiplexer/demultiplexer that demonstrates high transmission efficiencies and small sizes below 0.042 μm2. The proposed filters utilize slits in the center of rectangular and square-shaped resonators which results in a single-mode filtering effect. The study employs numerical and theoretical analyses, specifically the finite difference time domain method and coupled-mode theory, to evaluate the designed structures. The simulation results indicate that the rectangular-based demultiplexer has a cross-talk of −34 dB, a maximum transmission efficiency of 0.93, and an amplitude modulation of 0.44 dB, while the square-shaped resonator-based demultiplexer has a maximum transmission efficiency of 0.83, an amplitude modulation of 0.1 dB, and a cross-talk of −39.5 dB. These findings suggest that the proposed structures hold potential for application in optical communication systems.

On-chip plasmonic nanosensor based on multiple Fano resonances in rectangular coupled systems

The transmission characteristics of coupled multi-resonators integrated in metal-insulator-metal (MIM) waveguide systems are studied and used to design refractive nanosensors. The symmetry of this nanostructure can be easily broken by changing the relative distance between the multi-resonators, and the transmission spectrum for the system will exhibit double sharp Fano profiles. Simulation results show that the Fano profiles can be used for high-sensitivity refractive sensing with a sensitivity reaching ∼800nm/RIU and figure of merit (FOM) of ∼1.845×104. Moreover, the structure can be easily extended by adding another slender rectangular resonator, and multiple Fano resonances will appear in the spectrum. The new formed nanostructure can achieve a higher sensor sensitivity about ∼875 nm/RIU, and the FOM is 1.861×104. The proposed nanostructures will have great application prospects in on-chip information processing, biosensors and analytical chemistry.

Slow Light Realization Based on Plasmon-Induced Transparency in Γ-Shaped Rectangular Resonator Structures

Slow Light Realization Based on Plasmon-Induced Transparency in Γ-Shaped Rectangular Resonator Structures

Multiparameter Control of Energy Characteristics of Waveguide-Cavity Resonator-Slot Radiators

The problem of connecting three electrodynamic volumes with ideally conducting walls through electrically narrow rectilinear connecting slots and a radiating slot is solved by the generalized method of induced magnetomotive forces (MMF). The solution is obtained in an analytical form, taking into account the finite thickness of the walls of the connected volumes. The volumes are an infinite rectangular waveguide excited by a fundamental wave, a rectangular cavity resonator, and a half-space above an infinite plane. The energy characteristics of this system have been comprehensively studied depending on the geometric parameters of the constituent elements of the structure under consideration.

Frequency-Selective Surface-Based MIMO Antenna Array for 5G Millimeter-Wave Applications.

In this paper, a radiating element consisting of a modified circular patch is proposed for MIMO arrays for 5G millimeter-wave applications. The radiating elements in the proposed 2 × 2 MIMO antenna array are orthogonally configured relative to each other to mitigate mutual coupling that would otherwise degrade the performance of the MIMO system. The MIMO array was fabricated on Rogers RT/Duroid high-frequency substrate with a dielectric constant of 2.2, a thickness of 0.8 mm, and a loss tangent of 0.0009. The individual antenna in the array has a measured impedance bandwidth of 1.6 GHz from 27.25 to 28.85 GHz for S11 ≤ -10 dB, and the MIMO array has a gain of 7.2 dBi at 28 GHz with inter radiator isolation greater than 26 dB. The gain of the MIMO array was increased by introducing frequency-selective surface (FSS) consisting of 7 × 7 array of unit cells comprising rectangular C-shaped resonators, with one embedded inside the other with a central crisscross slotted patch. With the FSS, the gain of the MIMO array increased to 8.6 dBi at 28 GHz. The radiation from the array is directional and perpendicular to the plain of the MIMO array. Owing to the low coupling between the radiating elements in the MIMO array, its Envelope Correlation Coefficient (ECC) is less than 0.002, and its diversity gain (DG) is better than 9.99 dB in the 5G operating band centered at 28 GHz between 26.5 GHz and 29.5 GHz.

Graphene-based polarization insensitive ultrathin broadband terahertz absorber for material sensing applications

In this paper, a tunable broadband electromagnetic absorber for sensing applications at terahertz frequencies is proposed. The proposed design consists of a graphene based multiple slot loaded rectangular resonator, dielectric material and gold based metallic ground plane. The dimensions of proposed absorber’s unit cell are 10 μm × 10 μm. The proposed absorber has more than 90% absorption over a frequency spectrum of 4.86–18.33 THz (% fractional bandwidth > 116.22%). The proposed absorber is symmetric which makes the structure polarization insensitive. It has stable characteristics for incidence angle (θ) ≥ 40∘ for both Transverse-Electric (TE) and Transverse-Magnetic (TM) waves. The effects of different substrate materials, different analyte materials, variations in the graphene parameters and water level on the proposed absorber’s performance are also analyzed. This absorber can be used to detect different materials including water and thickness of water layer present on its top surface. The proposed graphene-based absorber dominates previously reported wideband THz absorbers in terms of relative bandwidth, more than 90% absorption peak values, oblique stability and overall volume.