PIER C | PIER Journals

2024-07-10

PIER C

Vol. 144, 199-205, 2024

download: 122

Separating the Bulk and Surface Second Harmonic Quadrupolar Contribution in Inversion Symmetric Crystals

Damián Zúiga-Avelar , Omar Palillero-Sandoval , Rosibel Carrada-Legaria , Muhammad Ahyad , Hendradi Hardhienata and Adalberto Alejo-Molina

We apply the third-order susceptibility tensor generated by the Simplified Bond Hyperpolarizability Model (SBHM) to address the long standing challenges in distinguishing the bulk and surface quadrupolar second-harmonic-generation (SHG) contributions in diamond lattices, such as silicon, which exhibit bulk inversion symmetry. Assuming that the quadrupolar contribution originates from the interface gradient of the excited electric field, we demonstrate through symmetry considerations and numerical calculations for Si(001) and Si(111) facet orientations that it is not possible to separate the different quadrupolar contributions when the incoming light is incident normally. However, we show that such separation is achievable with oblique incidence. Furthermore, we propose a novel experimental design to measure the bulk and surface quadrupolar SHG contributions separately by introducing a semi-vicinal surface. Using numerical SBHM simulations, we show for the first time that this semi-vicinal setup can prove the existence of spatial dispersion, a nonlinear dipolar bulk effect recently proposed. This approach may lead to a better understanding of various nonlinear contributions in silicon and enable precise nonlinear surface monitoring.

Separating the Bulk and Surface Second Harmonic Quadrupolar Contribution in Inversion Symmetric Crystals

2024-06-30

PIER C

Vol. 144, 189-198, 2024

doi:10.2528/PIERC24050904

download: 159

A Novel Four-State Switchable Dual-Band Bandpass Filter with High off -State Suppression Based on Multi-Mode Resonators

Bingjie Yang , Zhongbao Wang , Hongmei Liu , Mingming Gao and Shao-Jun Fang

A novel switchable dual-band bandpass filter (BPF) is proposed, where each passband can be independently controlled. The filter is composed of a tri-mode resonator, a dual-mode resonator, and feed lines coupling with the resonators. By controlling the PIN diodes loaded on the open end of the resonators, four operating states (i.e., dual bands, lower passband, upper passband, and all-stop band) are realized. A switchable dual-band BPF prototype is designed, fabricated, and measured with the center frequencies of 1.575 and 2.45 GHz having the bandwidths of 300 and 220 MHz, respectively. The prototype occupies an area of 0.128λ_g², where λ_g is the guided wavelength at the center frequency of the lower band (1.575 GHz). The measurement results indicate that the proposed switchable dual-band BPF has low insertion loss and high OFF-state suppression.

A Novel Four-state Switchable Dual-band Bandpass Filter with High OFF-state Suppression Based on Multi-mode Resonators

2024-06-29

PIER C

Vol. 144, 181-188, 2024

doi:10.2528/PIERC24032705

download: 172

Design of Miniaturized Dual Band-Pass Filter for ISM and Sub-6 GHz Spectrum by Employing Square Complementary Split Ring Resonator

Thupalli Shaik Mahammed Basha , Arun Raaza , Vishakha Bhujbal and Mathivanan Meena

In this proposed work, a miniaturized dual band-pass filter with enhanced selectivity and tunable transmission zero is proposed for an ISM and sub-6 GHz application. The conventional open and short circuited stubs are employed to operate dual band resonance. This prototype consists of a Square Complementary Split Ring Resonator (SCSRR), a unit cell interdigital circuit, and short and open circuited stubs. Further, the selectivity of the filter is enhanced by employing the SCSSR on the ground plane of the filter. The D-CRL resonator consists of a set of interdigital lines that act as main section of the filter which provides dual band-pass filter at ISM and sub-6 GHz bands with the bandwidths of 0.3 GHz and 0.75 GHz, respectively. The experimentally validated filter has 39 and 59% 3-dB fraction bandwidths, maximum insertion losses on both the bands below 0.31 dB, passband impedance matching more than 31 dB, group delay in the range of 0.25 to 0.61 ns, stopband to passband selectivity 89 dB/GHz, and passband to stopband selectivity 93 dB/GHz. The presented dual-band prototype is a better candidate to use in ISM and sub-6 GHz spectrum based high speed digital communication.

Design of Miniaturized Dual Band-Pass Filter for ISM and Sub-6 GHz Spectrum by Employing Square Complementary Split Ring Resonator

2024-06-29

PIER C

Vol. 144, 169-180, 2024

doi:10.2528/PIERC24042902

download: 119

Design of Double-Layer Circular Polarization Multiplex Focusing Metasurface Lens

Honggang Hao , Zhonglyu Cai , Bao Li and Pan Tang

Addressing the problem of Pancharatnam-Berry (PB) phase metasurface mutual coupling and single functionality under orthogonal circularly polarized wave incidence, a circularly polarized multiplexing focusing metasurface lens with polarization conversion functionality operating at 24 GHz is proposed using the method of jointly modulating PB phase and resonance phase. The metasurface unit is composed of two layers of dielectric plates covered with metal patterns on both sides separated by air. By varying the parameter sizes of each joint of the windmill-shaped metal pattern, the resonance phase of the unit can be independently controlled in the x-polarization and y-polarization directions, achieving a phase coverage close to 320° while maintaining a transmission magnitude greater than 0.8. By rotating the metal pattern, the size of the PB phase can be freely controlled. Adjusting the parameters of the metal pattern, the unit has a phase difference of 180° in the x- and y-polarization directions, achieving polarization conversion of circularly polarized waves, with its polarization conversion rate (PCR) approaching 100% near the operating frequency band. Simulation and test results show that under left-handed and right-handed circularly polarized wave incidence, the metasurface lens achieves single-point focusing effects at different positions, with focusing efficiencies of 45.6% and 45.9%, and focal spot sizes of -3 dB of 8.8 mm and 8.4 mm, respectively. This work is expected to be applied in fields such as K-band satellite communication, wireless power transmission, and 24 GHz automotive millimeter-wave radar.

Design of Double-layer Circular Polarization Multiplex Focusing Metasurface Lens

2024-06-26

PIER C

Vol. 144, 159-168, 2024

doi:10.2528/PIERC24052901

download: 121

A Racket-Like UWB MIMO Antenna with High Isolation

Zhonggen Wang , Guoxiang Song , Wenyan Nie , Ming Yang , Chenlu Li and Mingqing Wang

In this paper, a dual-port ultra-wideband (UWB) MIMO antenna is proposed, featuring a highly compact structure with dimensions of only 25×36×1.6 mm³. The designed antenna comprises two racket-shaped monopole antennas and a defective floor. Cross slots on the original T-shaped floor impede coupling current flow, significantly enhancing antenna isolation to achieve over 20 dB isolation across most frequency bands. The antenna operates at frequencies from 2.74~14.8 GHz, meeting the stringent design criteria for UWB antennas. Furthermore, the diversity performance of the antenna is rigorously analyzed by simulating the envelope correlation coefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), and channel capacity losses (CCL). The designed antenna demonstrates excellent performance through comprehensive simulation and testing, showcasing its potential for applications in UWB MIMO systems.

A Racket-like UWB MIMO Antenna with High Isolation

2024-06-25

PIER C

Vol. 144, 147-158, 2024

doi:10.2528/PIERC24052302

download: 110

Research on RCS Data Validation Based on SPWVD

Jiaxin Shi , Jun Hu , Zhiwei Gao , Lizhong Song , Huapeng Zhao , Ran Zhao , Wei Chen and Min Zhang

At present, Feature Selective Validation(FSV) is the most common data verification method of computational electromagnetics, and its effectiveness has been verified since its release in 2006, but since the main research object of this method is electromagnetic compatibility data, the 8 sets of data used for algorithm training also come from the field of electromagnetic compatibility, and its data curve has the characteristics of gentle waveform and small fluctuations. However, Radar Cross Section(RCS) data, especially high-frequency RCS data, usually have complex waveforms and drastic fluctuations, and the results obtained by the FSV method are often quite different from those obtained by experts. This paper proposes a new data verification method based on Smoothed Pseudo Wigner-Ville Distribution(SPWVD) algorithm for RCS data, which integrates the characteristics of RCS data and expert evaluation experience, and verifies its effectiveness in RCS data verification.

Research on RCS Data Validation Based on SPWVD

2024-06-21

PIER C

Vol. 144, 137-145, 2024

doi:10.2528/PIERC24050701

download: 95

Integrated Prediction of Condensation-Corrosion-Shielding Effectiveness of Metal Box with Gaps by Simulations

Jinjun Bai , Xiaolong Li , Jianshu Zhou and Ming Li

With the advancement of the intelligent process, all kinds of electrical equipment are highly dense in space, and the impact of electromagnetic interference on high-precision electronic equipment cannot be ignored. Metal shielding shell is one of the effective means to reduce electromagnetic interference. The heat dissipation holes on the surface of the shielded box are often used to maintain the normal operating temperature of the internal equipment, which will reduce the electromagnetic shielding effectiveness of the box. At the same time, due to the existence of capillary effect, condensation is very easy to occur at the hole gap, and the corrosion caused by it will further reduce the overall shielding effectiveness of the metal box. At present, there are few studies on the integrated prediction of ``condensation-corrosion-shielding effectiveness'' of metal boxes. Based on the commercial multi-physics simulation software COMSOL, this paper first simulates the condensation of a metal box in a high-humidity environment by constructing temperature, humidity, and moisture transport fields. Then, the current field and deformation field are constructed to predict the corrosion phenomenon at the gap of the metal box, and finally the electromagnetic field is constructed to predict the electromagnetic shielding efficiency of metal boxes at different frequencies. The joint multi-physics coupling simulation of condensation, corrosion and electromagnetic shielding effectiveness phenomena is realized.

Integrated Prediction of Condensation-corrosion-shielding Effectiveness of Metal Box with Gaps by Simulations

2024-06-21

PIER C

Vol. 144, 127-135, 2024

doi:10.2528/PIERC24032102

download: 223

Frequency Reconfigurable Circular Monopole Antenna with Key Shaped Ground Stub

Sweta Agarwal , Akanksha Singh and Manoj Kumar Meshram

In this paper, a unique low profile double stubbed ground plane frequency reconfigurable circular monopole antenna is introduced. The ground plane contains two RF-PIN diodes that enable the antenna to be reconfigured in ultra-wideband (3.2-10.8 GHz) and dual frequency (2.8-4.01 GHz and 7.56-8.2 GHz) modes. The proposed antenna is designed using an FR-4 substrate with the dimension about 33 × 28 × 1.6 mm³. The impedance matching of the antenna at ultra-wideband operation is improved by a defected ground structure. The measured and simulated results of the antenna are in close agreement. This antenna is useful for cognitive radio application.

Frequency Reconfigurable Circular Monopole Antenna with Key Shaped Ground Stub

2024-06-20

PIER C

Vol. 144, 117-126, 2024

doi:10.2528/PIERC24041203

download: 104

Bandwidth and Gain Improvement of Low-Profile MIMO Printed Arrays by Utilizing AMC Surface for Wireless Communications

Hossein Malekpoor

A compact dual-element microstrip antenna, employing a parasitic artificial magnetic conductor (AMC), is proposed for facilitating 4G and 5G wireless communications. The antenna design entails microstrip dipoles fed by a T-shaped feedline. Notably, the antenna achieves a measured bandwidth of 5.35-6.7 GHz (with S₁₁ ≤ -10 dB). To enhance performance, a proposed parasitic AMC reflector is integrated into the antenna structure. Incorporating a 3 × 3 AMC array, the antenna extends its -10 dB measured bandwidth from 4.57 to 6.80 GHz, catering to both 4G and 5G communication standards. Comparative analysis with an antenna lacking AMC reveals a reduced size of 34%, alongside a notable gain of 8 dBi and unidirectional radiation patterns. Additionally, a low-profile wideband two-element array, coupled with a 3 × 4 AMC reflector, demonstrates a broad bandwidth spanning from 4.55 to 6.8 GHz within the C-band. This configuration results in increased gains for the two antenna elements and ensures acceptable isolation exceeding 30 dB, crucial for multiple-input multiple-output (MIMO) systems. The efficiency and gain of all elements are obtained almost 90% and 8 dBi, respectively. Moreover, an AMC unit cell, well founded on a parasitic patch, resonates at 6.12 GHz with a bandwidth extending from 5.25 to 7.15 GHz. Furthermore, the offered equivalent transmission line model of the antenna with the AMC is demonstrated, yielding desirable results. This model accurately predicts the input impedance of the 1 × 2 array with AMC across a broad frequency band ranging from 4.63 to 6.73 GHz. This comprehensive coverage demonstrates the effectiveness and versatility of the offered model in characterizing the electrical behavior of the antenna system across a wide frequency band, thus facilitating its design and optimization for various applications.

2024-06-20

PIER C

Vol. 144, 107-115, 2024

doi:10.2528/PIERC24041301

download: 94

A Miniaturized Lens Unit Based on Current Path Extension as a Wireless Power Transfer Medium at 2.45 GHz

Xingyue Liu , Zhiwei Liu , Cheng Qiu , Zehua Luo and Yuxin Deng

A novel miniaturized lens unit at 2.45 GHz is presented in this manuscript. This unit is formed by a modified Malta cross and an ordinary cross, with a unit period of 0.2λ₀, where λ₀ denotes the unit wavelength. The ordinary cross unit creates a pathway for current between two units. Accordingly, it increases the current path and reduces the unit volume to a quarter of its original size. By adjusting the length of the Malta cross arm, it is possible to achieve the transmission phase at 2.45 GHz within a range of 0-360˚. Moreover, an improved PSO algorithm is used to optimize the phase of array elements. The optimization process is able to achieve a phase-shifting of ±18˚ within the range of 3.28λ₀. Simulation and measurement results show that the miniaturized lens unit can be used in the wireless energy transmission system.

A Miniaturized Lens Unit Based on Current Path Extension as a Wireless Power Transfer Medium at 2.45 GHz

2024-06-19

PIER C

Vol. 144, 99-105, 2024

doi:10.2528/PIERC24042202

download: 140

Improved Target Imaging Method for Arc Array Bistatic SAR with a Small Satellite Transmitter

Peigeng Lu , Zhennan Qin , Wei Xu , Pingping Huang , Weixian Tan and Yaolong Qi

Modern small satellite development represents a new trend, a new design idea, and it can be used as a transmitter to assist helicopter monitoring. The imaging model of the arc array bistatic SAR with a small satellite transmitter is studied. Due to the long resident time of small satellite platform and the wide-area observation capability of arc antenna, it has a wide application prospect in the field of earth detection and remote sensing. However, the motion state of the small satellite and the special scanning mode of the arc antenna have some effects on the SAR imaging results. Therefore, the imaging geometry of the arc array bistatic SAR with a small satellite transmitter is established, and an improved Chirp Scaling imaging algorithm is proposed. Firstly, the motion compensation function is used to compensate the migration caused by the high-speed motion of the small satellite. Then, the two-dimensional spectrum is derived by using standing phase principle and scaling function. Next, the coupling between range and azimuth is compensated by consistent range migration correction and secondary range compression, and residual phase is compensated in azimuth frequency domain. Finally, simulation results verify the effectiveness of the proposed method.

Improved Target Imaging Method for Arc Array Bistatic SAR with a Small Satellite Transmitter

2024-06-18

PIER C

Vol. 144, 85-97, 2024

doi:10.2528/PIERC24040302

download: 132

Active Disturbance Rejection Control Strategy for a Novel Wide-Rotor Bearingless Switched Reluctance Motor

Yonghong Huang , Meng Sun , Ye Yuan , Fan Yang and Xinyue He

A novel three-unit 8/4 wide-rotor bearingless switched reluctance motor has been designed to address the challenges of strong coupling and control difficulties between torque and suspension force in traditional bearingless switched reluctance motors. This motor features independent torque flux paths and suspension flux paths, allowing for separate control of torque and suspension force similar to traditional switched reluctance motors and active magnetic bearings. To tackle issues such as torque ripple, suspension force ripple, and reduced system robustness caused by external disturbances during operation, a torque sharing function and a suspension current PWM control strategy based on active disturbance rejection technology have been proposed. Firstly, mathematical models for the torque and suspension force of the three-unit 8/4 wide-rotor bearingless switched reluctance motor were established using Ansys simulation data and the Maxwell stress method. Subsequently, a torque sharing function and a suspension current PWM control system were developed based on these mathematical models. The endpoint of the commutation overlap zone was set at the maximum value of the phase inductance to eliminate the weak coupling effect of torque current on suspension force. Finally, active disturbance rejection control technology was introduced to compare its performance with that of traditional PID controllers in suppressing interference. Simulation results demonstrate that the proposed method ensures decoupling switching between each phase's motor torque and its associated suspension while enhancing anti-interference performance.

Active Disturbance Rejection Control Strategy for a Novel Wide-rotor Bearingless Switched Reluctance Motor

2024-06-16

PIER C

Vol. 144, 75-83, 2024

doi:10.2528/PIERC24051002

download: 93

Optimized Design of High Power Factor Fault-Tolerant Permanent Magnet Vernier Rim-Driven Machine

Kun Zang , Yaqian Cai , Jingwei Zhu , Haibo Liao , Mingxuan Li and Qing Liu

Fault Tolerant Permanent Magnet Vernier Rim-Driven Machines (FTPMV-RDM) have attracted much attention due to the advantages of high torque density and good fault tolerant capability. However, the traditional FTPMV-RDMs have a lower power factor which limits their broad application in marine electric propulsion system. This paper proposes a high power factor FTPMV-RDM topology in which the flux-concentrating Halbach array magnets are mounted on a rotor, and isolation slots are arranged on the stator teeth. A preliminary design of the FTPMV-RDM is presented. To tackle the problems of large computational burden and poor accuracy in traditional multi-objective genetic optimization algorithms, a novel optimization design method combining sensitivity-based optimization with sensitivity analysis is proposed. The performance of the machine is analyzed using Finite Element Analysis (FEA), and the results show that the proposed machine topology features a high power factor, high torque density, and strong fault-tolerant capability.

Optimized Design of High Power Factor Fault-Tolerant Permanent Magnet Vernier Rim-Driven Machine

2024-06-15

PIER C

Vol. 144, 65-74, 2024

doi:10.2528/PIERC24021401

download: 137

Dual-Wideband MIMO Antenna with Eight Elements for 5G and WLAN Communication

Lingrong Shen , Jianlin Huang , Qiangjuan Li , Tian Hong Loh and Gui Liu

This paper presents a compact 8 × 8 multiple-input-multiple-output (MIMO) antenna system designed to operate across two wide frequency bands suitable for fifth-generation (5G) mobile network and wireless local area network (WLAN) applications. Each antenna element comprises a radiator, a feeding line, and a defected ground plane. Each radiator consists of a first L-shaped radiator (FLR), a second L-shaped radiator (SLR), and an extra radiator (ER). To enhance the isolation, a defected ground structure (DGS) is employed between the antenna elements. The presented antenna operates across three frequency bands, namely, 3.5 GHz (3.3 GHz-3.8 GHz) and 4.9 GHz (4.8 GHz-5 GHz) 5G frequency bands, and 5.7 GHz (5.15 GHz-5.85 GHz) WLAN frequency band, exhibiting excellent isolation, surpassing 15 dB in both lower and higher frequency bands. The overall efficiency exceeds 58%, with an envelope correlation coefficient (ECC) value below 0.125.The simulation and measurement results are in good agreement.

Dual-wideband MIMO Antenna with Eight Elements for 5G and WLAN Communication

2024-06-14

PIER C

Vol. 144, 55-64, 2024

doi:10.2528/PIERC24041401

download: 186

A Low Profile Wideband Circularly Polarized Patch Antenna Using Metasurface

Yongkang Yuan , Minquan Li , Guocui Zhu , Xin Qu and Zhonghui Li

A low profile, wideband circularly polarized (CP) antenna using metasurface (MS) is proposed. The proposed antenna is composed of a square loop feeding structure and four driven patches positioned between the ground plane and the MS. Frist, The loop with truncated corners functions as a sequential phase feeder for the four driven patches. These patches are then capacitively coupled by the feeding loop to create a CP mode. Then a defective ground structure (DGS) is adopted to improve the impedance matching. Finally, using MS to generate extra CP minimum AR points to broaden the AR bandwidth. The MS is composed of a 4 × 4 truncated square patch array which enhances the impedance bandwidth and gain of the proposed antenna. The total dimensions of the proposed antenna are 50 mm × 50 mm × 3.124 mm (λ₀ × λ₀ × 0.062λ₀). The MS antenna in circular polarizations achieves a wide -10 dB impedance bandwidth of 37.5% (4.85-7.09 GHz) and a 3 dB axial ratio bandwidth (ARBW) of 20% (5.66-6.92 GHz). In addition, the maximum gain of 10.28 dB is achieved at 6.1 GHz, and the proposed MS antenna also has a flat gain across a broad frequency range from 4.5 GHz to 6.75 GHz.

2024-06-13

PIER C

Vol. 144, 43-53, 2024

doi:10.2528/PIERC24032001

download: 101

A Metasurface-Based Low-Profile Circularly Polarized Antenna with Double-Wide Beam for Global Navigation Satellite System

Ao Ni , Wen Wang , Jincheng Xue , Zhuopeng Wang and Lili Zhang

This study introduces a metasurface-based low-profile circularly polarized (CP) antenna with double-wide beam for global navigation satellite systems (GNSSs), which covers primarily BDS-2 B1 band and BDS-3 B1 band. At first, a T-slot structure achieving a compact design is presented to effectively miniaturize the antenna. Except that, a gear-type parasitic ring and eight parasitic microstrip lines are proposed to broaden both the half power beamwidth (HPBW) and axial ratio beamwidth (ARBW) of the antenna. Furthermore, a metasurface unit featuring double ``WIFI'' logo structure is introduced. This unit is expanded into a 7*7 metasurface loaded under the antenna, significantly improving its radiation characteristics. After experimentation, the proposed antenna achieves notable results: 121˚ HPBW and 214˚ 3 dB-ARBW at 1.561 GHz and 121˚ HPBW and 236˚ 3 dB-ARBW at 1.575 GHz. Additionally, it demonstrates more than 3.52 dBic gain across the whole frequency band, whose simulation and test results are in agreement. These results show that the antenna can be used for various satellite communication systems necessitating CP antennas with wide ARBW and HPBW.

2024-06-10

PIER C

Vol. 144, 33-41, 2024

doi:10.2528/PIERC24040105

download: 142

Design of Wider Impedance Bandwidth with Dual-Port CPW-Fed Slotted Patch Antenna for Wireless Communications

Prudhvi Raj Govathoti , Chirukuri Naga Phaneendra and Ketavath Kumarnaik

A Novel dual-port co-planar wave-guide (CPW)-fed rectangular patch antenna with L-shape and rectangular-shaped slots is proposed for wider impedance bandwidth for wireless communications applications. The dimensions of the overall proposed patch antenna are compact, with a size of 20 × 40 × 0.07 mm³. It operates from 14.6 GHz to 17.4 GHz with an impedance bandwidth of 2.8 GHz. The isolation between elements is greater than 15 dB within the band. A peak gain of 6.75 dBi and a reflection coefficient of -30 dB at operating frequency have been observed. The two-port (multiple-input and multiple-output) CPW-fed antenna parameters like envelope correlation coefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), channel capacity loss (CCL), and mean effective gain (MEG) are investigated. Simulated and measured characteristics are found to be satisfactory of proposed antenna model. The proposed antenna has utilized for wireless communication applications.

Design of Wider Impedance Bandwidth with Dual-port CPW-fed Slotted Patch Antenna for Wireless Communications

2024-06-09

PIER C

Vol. 144, 23-31, 2024

doi:10.2528/PIERC24032302

download: 263

Design of Ultra-Wideband Antenna with Quadruple Band Notch Reconfigurability

Ramesh Babu Sadineni , Kosuri Srinivasa Rao , Thotakura Sushma , Paruchuri Venkata Krishna Kanth , Veeravalli Ramakoteswara Rao and Dinesha Puttaraje Gowda

A miniaturized ultra-wideband (UWB) antenna with quadruple reconfigurable characteristics is proposed in this paper. The first step involves the development of an elementary rectangular patch antenna of size 40 × 40 mm², which is subsequently modified to demonstrate UWB properties. To incorporate quad-band notch features, the radiating surface of the patch antenna is etched with four U-shaped slots. The antenna has an impedance bandwidth ranging from 2.2 GHz to 12 GHz, with four specific notches located at 3.3 GHz (3.1-3.5 GHz), 3.8 GHz (3.6 GHz-4 GHz), 4.6 GHz (4.5 GHz-4.7 GHz), and 5.2 GHz (5.1 GHz-5.3 GHz). By incorporating four PIN diodes, the antenna is capable of attaining a range of sixteen reconfigurable states across the UWB spectrum. The design of this system successfully addresses the issue of interference caused by WiMAX, downlink C-band, Indian national satellite system, and Wireless LAN. A prototype is fabricated and tested. The simulated and experimental results are in good agreement.

Design of Ultra-Wideband Antenna with Quadruple Band Notch Reconfigurability

2024-06-08

PIER C

Vol. 144, 9-21, 2024

doi:10.2528/PIERC24013003

download: 104

Design and Optimization of Reverse Series Triple Coil Structure with Simultaneous Offset and Load Fluctuation Resistance

Xiaohua Shu , Jianbin Wang , Chenxi Zhang and Zhongqi Li

In wireless power transfer (WPT) systems, the horizontal misalignment between coils and variations in the load result in significant fluctuations in the transmission efficiency of the system. In this paper, a reverse series triple coil (RTC) structure is proposed. The RTC structure offers improved resistance to deflection in the direction of vehicle motion because of the magnetic field interaction of the reverse series coils. This adjustment helps maintain a more stable system transmission efficiency when the coils are deflected. At the same time, when the load resistance varies within a certain range, the system's transmission efficiency remains almost unchanged. This is because the addition of relay coils makes the system more adaptable to load changes and improves the system's load compatibility. The experimental results indicate that the RTC structure corresponds to 300% of the load variation range of the conventional reverse series dual-coil structure, within the range where the system transmission efficiency is not less than 95%, in the load variation range that satisfies the load equivalent resistance from 15 Ω to 68 Ω. During the offset process, the maximum system transmission efficiency fluctuation rate is 1.19% for a distance of 55% of the core width of the offset transmitting coil on the horizontal Y-axis, and the maximum efficiency reaches as high as 97.26%.

Design and Optimization of Reverse Series Triple Coil Structure with Simultaneous Offset and Load Fluctuation Resistance

2024-06-06

PIER C

Vol. 144, 1-8, 2024

doi:10.2528/PIERC24031306

download: 197

Triple Band Compact Textile Antenna Structure for Wearable Applications

Shankar Bhattacharjee and Monojit Mitra

A compact triple band antenna for wearable applications is presented in this paper. The antenna exhibits dual mode operation for ON/OFF body communication. The antenna has a patch like radiation pattern for OFF body communication and monopole like radiation pattern for ON body communication. Triple bands are achieved by incorporating an annular ring patch with the triangular patch. Tuning of the antenna and impedance matching has been done using two open ended rectangular slots and two shorting pins. As a result, the antenna has patch like radiation pattern at 2.5 GHz (ISM band), 3.5 GHz (Wi Max band) bands and monopole like radiation pattern at 5.5 GHz (WLAN band) band. The proposed antenna is compact in nature with a size of 70 × 70 × 2.1 mm³. User comfort has been taken into care with the use of all textile materials to fabricate the antenna except the SMA connector. A full ground plane in the proposed antenna ensures minimum coupling with human body and thereby a low SAR (specific absorption rate) value. Investigation of the antenna has been performed in both free space and on body scenarios.