PIER M | PIER Journals

2024-04-23

PIER M

Vol. 126, 147-155, 2024

download: 116

Dispersion and Eigenvector Error Analysis of Simplicial Cubic Hermite Elements for 1-d and 2-d Wave Propagation Problems

William Alexander Mulder and Ranjani Shamasundar

Dispersion error analysis can help to assess the performance of finite-element discretizations of the wave equation. Although less general than the convergence estimates offered by standard finite-element error analysis, it can provide more detailed insight as well as practical guidelines in terms of the number of elements per wavelength needed for acceptable results. We present eigenvalue and eigenvector error estimates for cubic Hermite elements on an equidistant 1-D mesh and on a regular structured 2-D triangular mesh consisting of squares cut in half. The results show that in 1D, the spectrum consists of 2 modes. If these are unwrapped, the spectrum is effectively doubled. The eigenvalue or dispersion error stays below 7% across the entire spectrum. The error in the corresponding eigenvectors, however, increases rapidly once the number of elements per wavelength decreases to one. In terms of element size, the dispersion error is of order 6 and the eigenvector error of order 4. The latter is consistent with the classic finite-element error estimate. In 2D, we provide eigenvalue and eigenvector errors as a series expansion in the element size and obtain the same orders. 2-D numerical tests in the timeand frequency-domain are included.

Dispersion and Eigenvector Error Analysis of Simplicial Cubic Hermite Elements for 1-D and 2-D Wave Propagation Problems

2024-04-16

PIER M

Vol. 126, 137-146, 2024

doi:10.2528/PIERM24021202

download: 151

Multi-Functional Metamaterial with Polarization and Wide Oblique Angle Insensitivity for X-Band

Punyatoya Routray and Debalina Ghosh

An optimal blend of relatively high frequency and effective atmospheric penetration renders the X-band a versatile selection for a wide range of applications. Hence, metamaterial absorber and frequency selective surface (FSS) as a band-stop filter and shielding element play a significant role in X-band. This article proposes a cost-effective, wide oblique and polarization-insensitive metamaterial, whose applications as an absorber and FSS having band-stop characteristics for X-band are explained. The isotropic unit cell of the proposed metamaterial is designed by an array of two subunit cells, where one is the 90˚ rotated version of the other with diagonal symmetry. Equivalent circuits of both subunit cells and array structure are systematically designed and analyzed, which provides scope for future modification according to the required frequencies. The proposed absorber provides three absorption peaks and absorptivity of more than 90% up to 60˚ oblique incidence angle. A good agreement between experimentally measured and simulated results is observed. For the use of the structure as FSS, it has been optimized to provide band-stop characteristics precisely for the X-band up to a wide oblique incidence angle. The proposed design can be used as an absorber, band-stop filter, reflector, and shielding element for the X-band.

Multi-functional Metamaterial with Polarization and Wide Oblique Angle Insensitivity for X-band

2024-04-14

PIER M

Vol. 126, 127-136, 2024

doi:10.2528/PIERM24020106

download: 289

A 1-Bit Metasurface with Adjustable Focus Achieved by Rotating Array

Bo Yin , Shubin Wang , Yun Li and Hao Zhang

The application scenarios of near-field focusing metasurfaces usually require scanning the target area. Passive metasurface requires a turntable to complete scanning due to its limited functionality. The active metasurface typically has a high cost because it needs to load PIN diodes. To address this issue, the article introduces a 1-bit reconfigurable metasurface that can achieve multi-focus tunability under fixed polarization through a rotating array. The 1-bit polarization-independent metasurface unit consists of three layers of metal. The top layer of the unit consists of three rectangular patches in the X-direction, the middle layer is a cross-shaped patch structure, and the bottom layer is a metal ground. The cross-shaped structure in the middle layer can easily provide the 1-bit reflection phase required for two orthogonal polarizations independently. Using a vertically polarized horn to illuminate the metasurface, the top layer's X-direction rectangular patches do not provide phase for vertical polarization. By rotating the array where the cross-shaped patches are located by 90°, the phase shift provided can achieve two focal points. On this basis, rotate the upper array by 90°, making the rectangular patches change from the X-direction to the Y-direction. Meanwhile, the current of the cross-shaped patches is blocked under vertical polarization illumination. By changing the upper rectangular patches, a third independent phase can be provided. After size optimization, a third focus can be formed. The proposed 1-bit focusing-adjustable metasurface array has a simple structure, low cost, and enhanced utilization rate of the metasurface array. It has a high application prospect in projects such as microwave imaging.

A 1-bit Metasurface with Adjustable Focus Achieved by Rotating Array

2024-04-12

PIER M

Vol. 126, 117-126, 2024

doi:10.2528/PIERM24011101

download: 415

Design of a Simple Four-Port UWB-MIMO Antenna Based on a Fan-Shaped Isolator

Wanying Ren , Zhonggen Wang , Ming Yang , Jinzhi Zhou and Wenyan Nie

In this paper, a novel, highly isolated ultra-wideband multiple-input, multiple-output antenna design for indoor communication is proposed. The overall size of the antenna is only 36 × 36 mm², and it contains four monopole antenna units and a fan-shaped isolated structure. Each antenna cell is composed of a U-shaped patch element and a defected rectangular ground structure. The fan-shaped decoupling structure effectively absorbs coupling currents, significantly improving isolation. As a result, the proposed antenna system can cover the entire ultra-wideband and receive a resonant frequency of 2-11.08 GHz. The results demonstrate that the antenna's isolation is greater than 15 dB in the operating band. Furthermore, the antenna exhibits good radiation characteristics and reasonable envelope correlation coefficients.

Design of a Simple Four-port UWB-MIMO Antenna Based on a Fan-shaped Isolator

2024-04-10

PIER M

Vol. 126, 107-115, 2024

doi:10.2528/PIERM24022602

download: 347

Design of a Three-Channel Frequency Multiplexing Metasurface in Full Space

Qinxuan Ling , Jinfeng He , Honggang Hao , Zhonglyu Cai and Min Wang

The multifunctional metasurface offers a high degree of flexibility in manipulating electromagnetic waves. However, the majority of its functions are limited to the reflection or transmission space in a single band, restricting the utilization of electromagnetic information. This paper proposes a three-channel multifunctional frequency multiplexing coding metasurface based on the Fabry-Perot cavity principle. It consists of two layers of orthogonal metal gratings and a cross-shaped, oblique open loop structure in the intermediate layer. Simulation results reveal that at an incidence of 22 GHz, the polarization conversion and focusing functions of the transmitted wave are accomplished. Similarly, at an incidence of 31 GHz, the beam deflection function of the reflected wave is observed. Furthermore, at an incidence of 32 GHz, the radar scattering cross-section reduction function of the reflected wave is achieved. In addition to achieving high efficiency, miniaturization, and compactness, the proposed metasurface effectively enhances the spatial utilization of electromagnetic information. As a result, potential applications in multifunctional integrated systems, including wireless communication, sensing technologies, and radar systems, are vast.

Design of a Three-channel Frequency Multiplexing Metasurface in Full Space

2024-04-09

PIER M

Vol. 126, 99-106, 2024

doi:10.2528/PIERM23110503

download: 204

Accurate on Wafer Calibration and S-Parameter Measurement Setup for InP -Based HEMT Devices to 220 GHz

Haiyan Lu , Jixin Chen , Zhongfei Chen , Yuan Sun , Luwei Qi , Siyuan Tang , Hongqi Tao , Tangsheng Chen and Wei Hong

In this paper, the on-wafer S-parameter measurement of InP-Based HEMT devices up to 220\,GHz is presented. The calibration kits utilizing a CPWG structure are meticulously designed on an InP substrate. The corresponding structure for calibrating the reflection mechanism is designed in order to reduce the influence between the two ports during the calibration process and improve isolation. The TSVs process is employed to attain broadband load. The design concept of the calibration structure is discussed, and the simulation results up to 220\,GHz are provided for demonstration. The measurement results encompass frequency ranges of 0.2-66 GHz, 75-110 GHz, 110-170 GHz, and 170-220 GHz. Moreover, the test results obtained from different calibration methods for InP HEMT devices are compared and analyzed. By employing interpolation techniques, comprehensive S-parameter data for actual DUTs ranging from 0.2 to 220 GHz is successfully obtained. Furthermore, the intrinsic parameters C_gs is extracted from device test results, and various calibration methods are utilized for comparison. The extrapolated maximum current gain cut-off frequency f_T based on a -20 dB/decade slope in H₂₁ is determined as 252 GHz while the extrapolated device maximum oscillation frequency fmax calculated through the maximum stable gain (MSG)/the maximum available gain (MAG) and Umason approaches reaches up to 435 GHz.

Accurate on Wafer Calibration and S-parameter Measurement Setup for InP-based HEMT Devices to 220 GHz

2024-04-07

PIER M

Vol. 126, 89-98, 2024

doi:10.2528/PIERM24010702

download: 314

Thermal Simulation for Magnetic Coupler of Wireless Power Transfer Electric Vehicles by Using Heat Sink and Thermoelectric Cooler

Umar Farooq , Shahryar Shafique , Muhammad Asif , Muhammad Arslan , Poramed Wongjom , Rizwan Ullah , Anton Zhilenkov , Saleh Mobayen and Wanchai Pijitrojana

In challenging operational environments such as underground buildings beneath roadways, the reliability and performance of wireless power transfer (WPT) systems for electric vehicles (EVs) heavily hinge on the operating temperature of the magnetic couplers. Addressing this, this study introduces a novel approach employing heat sink and thermoelectric cooler technologies to mitigate temperature rise in magnetic couplers, which is particularly crucial for high-power applications. Utilizing ANSYS simulation, the study evaluates a WPT high-power application coil model with a total output power of 2 KW and an 18 cm air gap, with a 3.5 cm adjacent alignment to enhance thermal performance on both transmitter and receiver sides. Results demonstrate significant thermal enhancement, reducing the temperature of coils from 63˚C to 54˚C solely with the heat sink and further down to 48˚C with the combined implementation of both heat sink and thermoelectric cooler. These measures effectively dissipate heat from the coils into the surrounding air, ensuring system efficiency and stability while facilitating optimal functionality of system components.

Thermal Simulation for Magnetic Coupler of Wireless Power Transfer Electric Vehicles by Using Heat Sink and Thermoelectric Cooler

2024-04-03

PIER M

Vol. 126, 81-88, 2024

doi:10.2528/PIERM23103003

download: 428

Ultra Thin Highly Sensitive Metamaterial Absorber Based Refractive Index Sensor for Detecting Adulterants in Alcohol

Sagnik Banerjee , Ishani Ghosh , Mazed Billah Fahad , Santosh Kumar Mishra , Rahul Yadav and Bhargav Appasani

This research provides a unique design of a terahertz-frequency metamaterial absorber. The absorber shows resonance at frequency 5.01THz where the peak absorption is 99.5%. A staggering quality factor of 125.25 is also discovered. Since the radiation is non-ionizing, the metamaterial absorber can function as a refractive index sensor and can be used for sensing applications. To support the chosen design parameter values, parametric analysis was performed. The resonance mechanism has been clearly explained using the surface current distribution plot, and the metamaterial nature of the sensor has also been justified using the impedance plot, followed by the plot showing the permeability and permittivity at the resonance frequency. By detecting changes in the refractive index of the surrounding medium, the proposed sensor finds application in detecting the percentage of water and percentage of methanol in alcohol solution. Methanol and water are two prominent contaminants of alcohol. It can detect the percentage of water in alcohol with a sensitivity of 2.105 THz/RIU and can detect percentage of methanol in alcohol with a sensitivity of 1.999 THz/RIU. This work can inspire future research on using THz metamaterial absorbers for quality assessment of food products and beverages.

$Ultra Thin Highly Sensitive Metamaterial Absorber Based Refractive Index Sensor for Detecting Adulterants in Alcohol$

2024-04-02

PIER M

Vol. 126, 73-80, 2024

doi:10.2528/PIERM24012403

download: 356

An Antipodal Vivaldi Antenna with a Lower Cutoff Frequency Based on Spoof Surface Plasmon Polaritons and Corrugated Edges

Baoping Ren , Chenguang Zhao , Xuehui Guan and Shaopeng Wan

In this paper, an antipodal Vivaldi antenna (AVA) with lower cutoff frequency is proposed based on spoof surface plasmon polaritons (SSPPs) and corrugated edges. Firstly, the gradient slots are etched on the external edges of two radiation arms of the conventional antipodal Vivaldi antenna. As a result, the cutoff frequency at the low frequency side will decrease slightly because the surface current path of the antenna is increased. More importantly, the SSPPs structure with identical units is etched on the inner side of two radiation arms, resulting in a large reduction of the cutoff frequency for the larger propagation constant of the SSPPs structure compared with radiation arms of the conventional antipodal Vivaldi antenna. Additionally, SSPPs structure on the stripline ensures good momentum matching and mode matching between quasi-TEM mode and SSPPs mode. Besides, to improve the gain at the high frequency region of the operation band, the introduced SSPPs structure on the inner side of two radiation arms is further optimized by varying groove depths. Experimental results demonstrate that the designed antipodal Vivaldi antenna exhibits a good radiation performance with a low cutoff frequency of 2.8 GHz and a maximum gain of 9.3 dBi.

An Antipodal Vivaldi Antenna with a Lower Cutoff Frequency Based on Spoof Surface Plasmon Polaritons and Corrugated Edges

2024-04-01

PIER M

Vol. 126, 65-72, 2024

doi:10.2528/PIERM23122803

download: 358

Metamaterials Photonic Filter Based on Electromagnetically Induced Transparency Resonance

Younes Errouas , Ilyass El Kadmiri , Youssef Ben-Ali , Abdelaziz Ouariach and Driss Bria

In this paper, we give an analytical demonstration of electromagnetic induced transparency (EIT) resonance by a simple photonic device consisting of two grafted resonators (metamaterials of type Epsilon Negative Gauchy (ENG)) of lengths d₂ and d₃. Then, we study theoretically the transmission spectrum and the dispersion relation of periodic photonic comb-like waveguides system built of periodic segments of length d₁ (of right-handed material). The electrical permittivity, ε, of the two asymmetric resonators with lengths d₂ and d₃, depends on the frequency of the incident waves (ENG material). The presence of geometrical (ENG resonators) defects inside the perfect structure creates the defect modes inside the band gaps. Consequently, we demonstrate the existence of two filtered frequencies. This structure can be used as a new photonic filter in the microwave range with an important quality factor and a high transmission rate.

Metamaterials Photonic Filter Based on Electromagnetically Induced Transparency Resonance

2024-04-01

PIER M

Vol. 126, 37-63, 2024

doi:10.2528/PIERM24013106

download: 400

Lasers Based on Periodic and Quasiperiodic Planar Feedback Cavities: Designs, Principle, and Potential Applications

Anwer Hayat , Alamgir , Yi Jin , Naeem Iqbal , Tianrui Zhai and Sailing He

Planar feedback micro-nanoscale cavities, shaped by advances in nanofabrication, have revolutionized laser technology, giving rise to chip-scale, low-threshold lasers with wide-ranging applications, spanning from atmospheric investigation to incorporation intocentral devices such as smartphones and computer chips. The complicated designs of these cavities, shaped by the physics of periodic and quasiperiodic structures, empower efficient manipulation of light-matter interaction and coherent light coupling, minimizing losses. This review thoroughly explores the underlying concepts and crucial parameters of planar feedback microcavities, shedding light on the photophysical behavior of recent gain materials pivotal for realizing optimal lasing properties. The examination extends to photonic crystal bandgap (PhC BG) microcavity lasers, specifically with periodic and quasiperiodic architectures. In-depth assessments probe into the principles and designs of each architecture, exploring features such as wavelength selectivity, tuneability, lasing patterns, and the narrow linewidth characteristics inherent in distributed feedback (DFB) microcavity lasers. The review highlights the intriguing characteristics of non-radiative bound states in the continuum (BIC) within periodic architectures, emphasizing trends toward high-quality factors, low thresholds, and directional and vortex beam lasing. It also explores the nascent field of Quasiperiodic (QP) microcavity lasers, addressing challenges related to disorder in traditional periodic structures. Comparative inquiries offer insights into the strengths and limitations of each architecture, while discussions on challenges and future directions aim to inspire innovation and collaboration in this dynamic field.

Lasers Based on Periodic and Quasiperiodic Planar Feedback Cavities: Designs, Principle, and Potential Applications

2024-03-31

PIER M

Vol. 126, 29-36, 2024

doi:10.2528/PIERM24020207

download: 344

A Stable and Efficient Interpolation Method for Two-Dimensional Periodic Green's Functions

Lian Feng Ma , Qing Guang Zhao , Chong Guo and Yi Ren

This paper presents an efficient and stable interpolation method for calculating two-dimensional periodic Green's function and its gradient. The method consists of two steps: constructing an interpolation table in the first step and using linear interpolation to extract the desired Green's function from the interpolation table in the second step. In the construction of the interpolation table, several properties of the two-dimensional periodic Green's function are fully utilized, which minimize the size of the interpolation table. When the elements in the interpolation table are computed, all possible singular terms are removed, ensuring that the interpolation function maintains high linearity even under extreme skew periodic grids. This means that linear interpolation can guarantee sufficient accuracy. Numerical results demonstrate effectiveness of the proposed method, making it suitable for combining with numerical methods for electromagnetic field calculation and analysis of periodic structures.

A Stable and Efficient Interpolation Method for Two-dimensional Periodic Green's Functions

2024-03-28

PIER M

Vol. 126, 19-27, 2024

doi:10.2528/PIERM24030801

download: 359

A Triple Phase Shift Control Method for Bidirectional Inductive Power Transfer (BIPT) Systems with Fully-Compensated Series-Series (SS) Topology

Liujie Wan , Xiaohe Zhao , Jingkui Mao and Xiu Zheng

A bidirectional inductive power transfer (BIPT) system of full-compensated series-series (SS) topology with full bridge converters on both primary and secondary sides is analyzed in this paper. The steady-state electrical characteristics of the BIPT system under triple-phase-shift control are obtained, based on which, the conditions for achieving the maximum transfer efficiency of the intermediate circuit and zero voltage switching of all switches are derived. Triple Phase-Shift Control (TPSC) strategy was proposed for the control of the two inner phase shifted of the primary and secondary side full bridge converters and the fundamental excitation voltage phase shift, which achieved the maximum transfer efficiency of the intermediate circuit and zero voltage switching of all switches. The proposed control method was verified through simulation. The results showed that the control strategy can realize the bidirectional energy transfer of the IPT system, the efficiency optimization of the intermediate link, and the zero-voltage turn-on of all switching devices under various load conditions.

A Triple Phase Shift Control Method for Bidirectional Inductive Power Transfer (BIPT) Systems with Fully-compensated Series-Series (SS) Topology

2024-03-24

PIER M

Vol. 126, 11-18, 2024

doi:10.2528/PIERM24020201

download: 463

UHF-Band Solid Sensor Based on Tweaking Electric Field Coupled Resonator for Material Characterization

Syah Alam , Indra Surjati , Lydia Sari , Yuli Kurnia Ningsih , Munanda Yorias Fathanah , Yessi Kartini Gultom , Ghathfan Daffin , Teguh Firmansyah and Zahriladha Zakaria

This paper proposes a UHF-band microwave sensor for solid material detection based on a tweaking electric field coupled (ELC) resonator. The microwave sensor operates at a low resonant frequency of 0.82 GHz to characterize solid materials with a permittivity range of 1-9.8. The location of the sensing area is determined based on the surface of the resonator with the highest electric field. The permittivity of the sample is determined based on perturbation theory by observing the frequency shift relative to changes in the permittivity of the sample placed in the sensing area of the proposed sensor. From the measurement process, the proposed sensor has a normalized sensitivity (NS) of 1.49%, frequency detection resolution (FDR) of 0.012 GHz, and an average accuracy of 96.72%. This work has a significant contribution and can be recommended for several applications including the pharmaceutical, biomedical, and materials industries.

UHF-band Solid Sensor Based on Tweaking Electric Field Coupled Resonator for Material Characterization

2024-03-24

PIER M

Vol. 126, 1-10, 2024

doi:10.2528/PIERM23103104

download: 408

Conformal Microstrip Antennas on the Rocket Cylinder

Anita Pascawati , Muh Fakhri , Aditya Inzani Wahdiyat , Idris Eko Putro , Sonny Dwi Harsono , Mirza Zulfikar Rahmat , Rahmat Alfi Duhri , Kandi Rahardiyanti , Herma Yudhi Irwanto , Yuyu Wahyu , Arief Rufiyanto , Budi Sulistya , Evi Nur Qomariya , Cahyaning Retno Rahayu , Rizki Fadhila Ridho and Muhammad Reza Kahar Aziz

This paper presents the design of conformal microstrip antennas wrapped around on a rocket cylinder. These antennas should exhibit favorable S₁₁-parameter values within the desired radio frequency range and an omnidirectional radiation pattern. Given their external placement on rockets, the challenge in this context is to ensure heat resistance. Two types of conformal microstrip antennas are developed to address this issue: one features an 8x1 array of rectangular patch (RP) elements, and the other consists of a single long rectangular patch (LP) element. Each antenna is wrapped around the rocket cylinder, with the patch array elements tailored to match the cylinder circumference to achieve an omnidirectional radiation pattern. Both antennas operate at a resonant frequency of 2.44 GHz and are constructed using RT/duroid 5880, a flexible material with a low dielectric constant. The antennas designs are assessed through computer simulations, followed by fabrication and measurements to analyze their performance against simulation results. The results indicate that the conformal RP antenna displays an S₁₁ value of -24.512 dB at the center frequency of 2.445 GHz featuring a 48 MHz bandwidth, while the conformal LP antenna discloses an S₁₁ value of -16 dB at the center frequency of 2.44 GHz having a wider bandwidth of 55 MHz. Both of the conformal RP and LP antennas exhibit an omnidirectional radiation pattern with a maximum gain of 6.13 dB and 7.21 dB, respectively. Following simulation and testing results, the antennas can tolerate temperatures up to 71.8˚C during flight tests. Although temperature variations trigger slight frequency shifts, these deviations are insignificant. Finally, the measurement results agree with the simulation ones.