PIER C | PIER Journals

2024-10-14

PIER C

Vol. 148, 171-179, 2024

download: 30

Design of Multimode Hybrid Power Amplifier Based on Interdigital Bandpass Filter

Shiwei Zhao , Linsong Li , Sijia Li , Zuqiang Zhang , Longfei Zhou and Fei Zhao

This paper introduces a multimode hybrid continuous class power amplifier utilizing a band-pass filter. It integrates resistive response amplifiers operating in three modes: class F, class J, and class F-1. Instead of the traditional quarter-wavelength line for harmonic control, an interdigital band-pass filter is utilized to manage harmonic impedance, enabling broadband operation, high efficiency, reduced circuit size, and improved out-of-band rejection. To demonstrate the approach, a multimode hybrid broadband high-efficiency power amplifier designed for 2 to 3.8 GHz range, achieving drain efficiency from 56.3% to 75.5%, saturated output power ranging from 39.1 to 41.2 dBm, and gain between 11.1 and 13.2 dB, is detailed and fabricated in this paper.

Design of Multimode Hybrid Power Amplifier Based on Interdigital Bandpass Filter

2024-10-10

PIER C

Vol. 148, 157-169, 2024

doi:10.2528/PIERC24073104

download: 55

A Novel Single-Layered Dual-Wideband Circularly Polarized Asymmetric Slot Antenna for Wireless Applications

Pradeep Hattihalli Shankaraiah , Neelawar Shekar Vittal Shet and Krishnamoorthy Kandasamy

This work focuses on the design and implementation of a dual-wideband asymmetric square-shaped slot radiator with coplanar waveguide (CPW) feed for circular polarization (CP) characteristics. The proposed radiator has inward ground plane extensions in the form of square and rectangular strips on the diagonal corners of the slot. By optimizing the size of strips, a dual-band antenna with CP behaviour is obtained. The inverted L-shaped grounded strip improves axial ratio bandwidth (ARBW). The extended signal line terminated in a wide tuning stub significantly improves impedance bandwidth (IBW) and ARBW. The designed asymmetric slot radiator is fabricated using an FR-4 substrate material of dimensions 50 × 50 × 1.6 mm³. This antenna design gives flexibility to alter polarization sense at the dual frequency bands. Further, edge effects are analyzed through electric field distribution, and their impact on impedance and AR characteristics are studied. It is designed, fabricated, and tested, and shows right-hand circular polarization (RHCP) response at 3 GHz and 7.5 GHz in the +Z direction. The experimentally verified results show -10-dB impedance bandwidth (IBW) of 40.12% (range from 2.61 GHz to 3.92 GHz) and 40.21% (range from 6 GHz to 9.02 GHz), and 3-dB ARBW are 20% (range from 2.70 GHz to 3.30 GHz) and 40.21% (range from 6 GHz to 9.02 GHz) at the resonance bands. The experimentally measured and simulated performance parameters of the prototype are in close agreement. The proposed perturbed slot radiator is well suited for Wi-Fi 6E communication and remote sensing applications.

A Novel Single-layered Dual-wideband Circularly Polarized Asymmetric Slot Antenna for Wireless Applications

2024-10-07

PIER C

Vol. 148, 145-156, 2024

doi:10.2528/PIERC24080402

download: 109

Wearable Wideband Textile Coplanar Vivaldi Antenna for Medical and IoT Application

Nurhayati Nurhayati , Agam Nizar Dwi Nur Fahmi , Pradini Puspitaningayu , Oce Wiriawan , Brian Raafi'u , Fitri Adi Iskandarianto , Ahmed Jamal Abdullah Al-Gburi , Atul Kumar Varshney and Safpbri Johari

Wearable technologies will be extremely useful in the future life. This research proposes a textile wideband coplanar Vivaldi antenna constructed from felt substrate and two distinct types of patches, shieldit and copper tape integrated with a wearable device. This study also altered the slope of the tapered slot on the antenna's front and side to see how it affected the bandwidth and directivity antenna performance. An IoT wearable device that was connected to a microcontroller via a DS18B20 body temperature sensor and a MAX30100 sensor for heart rate and oxygen level monitoring was paired with the textile antenna. Based on the simulation findings, it was discovered that a 1 mm thick felt substrate material combined with a copper tape patch produces a workable frequency range of 2.6 GHz to 8.7 GHz, a minimum S₁₁ of -44.93 dB at 3 GHz, and a fractional bandwidth up to 107%. According to the simulation results, the antenna's side and front tapered slots have an impact on directivity and return loss. Directivity at 3 GHz can be raised by 2.63 dBi, from 1.94 dBi to 4.57 dBi, by varying the Vivaldi antenna form on both sides of the patch. The data from the sensor was successfully conveyed by combining an IoT wearable device with a textile antenna. Thus, we deduce that the textile coplanar Vivaldi antenna is appropriate for Internet of Things applications.

Wearable Wideband Textile Coplanar Vivaldi Antenna for Medical and IoT Application

2024-10-07

PIER C

Vol. 148, 137-143, 2024

doi:10.2528/PIERC24072502

download: 47

A W-Band Waveguide-to-Suspended Stripline in-Line Transition with Single-Side Fin-Line

Baochen Du , Yang Chen and Hongfu Meng

A novel full W-band in-line waveguide-to-suspended stripline transition based on reversed single-sided fin-line structure is proposed. To achieve wideband mode conversion and impedance matching, a combination of an asymmetric antipodal fin-line and a reversed single-sided fin-line structure is employed. The electromagnetic (EM) wave undergoes a mode transition from TE10 mode to quasi-parallel plate waveguide(Q-PPW) mode through the asymmetric antipodal fin-line. Subsequently, the mode transforms into suspended stripline mode due to the reversed single-side fin-line structure. The proposed in-line transition achieves a wide bandwidth through a simplified structural design. To assess the performance of the proposed design, a back-to-back in-line transition operating at the W-band is fabricated and measured. The measured results of the back-to-back structure demonstrate that the reflection coefficient is better than -13 dB, and the insertion loss is less than 0.54 dB across the entire W-band (75-110 GHz). The advantages of the proposed transition, such as wide bandwidth and simple structure, render it highly promising for advanced millimeter-wave circuits and systems.

A W-band Waveguide-to-suspended Stripline In-line Transition with Single-side Fin-line

2024-10-03

PIER C

Vol. 148, 127-135, 2024

doi:10.2528/PIERC24082703

download: 44

Compact 2 × 1 Polarization Reconfigurable Dielectric Resonator Antenna Array Using Adaptable Feeding Network

Yazeed Mohammad A. Qasaymeh

In this paper, a compact 2 × 1 dielectric resonator antenna (DRA) array with circular polarization (CP) agility array is presented. The array is formed of two novel resonating elements, and each is composed of a pentagonal slot (PS) coupling a rectangular dielectric resonator (RDR). The proposed resonating element emits two degenerate orthogonal modes TE_δ11^x and TE_δ21^y, confirming the CP radiation performance. The proposed resonator is utilized to portray a 2 × 1 sequentially rotated (SR) array with the ability to alter the CP polarization orientation. The signal at the feeding network input splits into two paths with equal magnitudes and phase progression phase by means of Wilkinson power divider (WPD). To obtain the 90˚ phase shifting between the WPD output signals, a single branch-line coupler (BLC) is utilized. Considering the fact that the shifting orientation of the BLC output depends on which of the two BLCs is used as in input, the signal phase at the BLC can be controlled to yield a right hand circular polarization (RHCP) or left hand circular polarization (LHCP). To control the switching between the BLC output ports phase state, two PIN diodes are used at the BLC input ports. The 50 × 50 mm² archetype achieves a bandwidth of 5.17% with a maximum realized gain of 7 dBic and a polarization purity of 4.4%. The findings of the proposed array make it a decent candidate for application using a 5.8 GHz band.

Compact 2 × 1 Polarization Reconfigurable Dielectric Resonator Antenna Array Using Adaptable Feeding Network

2024-10-03

PIER C

Vol. 148, 117-125, 2024

doi:10.2528/PIERC24060504

download: 34

A Cross-Layer Resource Allocation Algorithm for Broadband Power Line Communication OFDM Systems

Mengxu Fang , Mingxin Liu , Leitao Wang and Xiaoxia Zheng

Adaptive orthogonal frequency division multiplexing (OFDM) technology is used in OFDM systems for broadband power line communications to effectively increase the communication rate. Existing research is mostly based on the single-layer network state for the resource allocation, and the required rate is often a static preset value. When there are significant differences in the signal-to-noise ratios of the sub-carriers, the system cannot adaptively adjust the required resources according to the quality-of-service (QoS) demand and the actual network, resulting in the waste of communication resources or the inability to meet some user communication needs. In this paper, a cross-layer resource allocation model is established for the system's cross-layer resource allocation problem through the data mapping among the application layer, data link layer, and physical layer. In the MAC layer, according to the quality of service (QoS) requirements of electric power multi-service, the data packet waiting delay and the packet loss are mapped to transmission rate proportionality constraints of real-time/non-real-time users through the utility function. A physical layer resource allocation model based on proportional constraints is constructed, and then an improved genetic algorithm is used for the resource allocation. Finally, through the simulation experiments in a typical power line channel environment, it is found that the proposed algorithm improves the total throughput by 4%~6% over the existing two power line carrier resource allocation algorithms under the multi-service cross-layer resource allocation, and its proportional fairness is better. The proposed algorithm is able to maximize the system capacity while ensuring the QoS requirements, effectively improving communication quality.

A Cross-layer Resource Allocation Algorithm for Broadband Power Line Communication OFDM Systems

2024-10-03

PIER C

Vol. 148, 109-115, 2024

doi:10.2528/PIERC24062103

download: 33

Two-Dimensional Array Coverage Pattern Recalculating Under Faulty Elements

Ahmed Jameel Abdulqader

Faulty elements (FEs) in a two-dimensional array (TDA) directly impact the performance and configuration of the coverage pattern due to the long operation of the antenna system. Therefore, the process of dealing with these failed elements, knowing their locations, and reducing their negative impact in practice is the main goal of designing a large TDA. In this article, three types of FE locations (faulty random elements, faulty clustered elements, and faulty subarray elements) are studied. Based on the genetic algorithm (GA), the damaged coverage pattern due to the presence of these failed elements is recalculated. The method relies on re-optimizing the amplitude-only weights of non-FE optimally while neglecting the the defective elements. Therefore, the entire TDA elements do not need to be redesigned again but rather rely on the working elements only. This gives great simplification for recalculating the coverage pattern. To further control the coverage pattern in terms of the main beam width in terms of the directivity (D), the first null to null beam width (FNBW) and the sidelobe level (SLL), a fitness function is added to the optimization process under specific constraints. Simulation results for different scenarios are presented to demonstrate the validity and effectiveness of the proposed approach for dealing with FE.

Two-dimensional Array Coverage Pattern Recalculating under Faulty Elements

2024-09-25

PIER C

Vol. 148, 97-107, 2024

doi:10.2528/PIERC24052501

download: 74

Impact of Rainfall on 5G Millimeter Wave Channels

Lee Loo Chuan , Mardeni Bin Roslee , Chilakala Sudhamani , Sufian Mousa Ibrahim Mitani , Athar Waseem , Anwar Faizd Osman , Fatimah Zaharah Ali and Yasir Ullah

Wireless connections in 5G technology are driving the rapid growth of intelligent transport systems and vehicle communications. Wireless channels are impacted by weather, which is most noticeable in millimeter wave bands. This includes rain, fog, snow, sand, and dust. 5G networks now support diverse applications with speed and quality. In an effort to enable the use of millimeter wave frequencies, a recent study examined the impact of dust and sand on 5G channels. This paper examines the impact of heavy and frequent rainfall, along with horizontal polarization, on the propagation of millimeter waves in urban and highway settings. Using theoretical and optimization techniques, the effects of rainfall attenuation, path loss, and connection margin are evaluated at various millimeter wave frequencies. Dependencies on rainfall rate, path variation, and operating frequency are shown by the simulation results. In urban and highway situations, mean path loss and error statistics are examined with and without rainy attenuation. It is observed that the particle swarm optimization approach achieves 94% accuracy in signal propagation, which will enhance the path loss, received power and overall system performance.

Impact of Rainfall on 5G Millimeter Wave Channels

2024-09-24

PIER C

Vol. 148, 83-95, 2024

doi:10.2528/PIERC24070401

download: 65

Isolation and Bandwidth Enhancement of Compact Wideband MIMO for Sub-6 GHz , Ku-Band and Millimeter-Wave with UWB Applications

Kudumu Vara Prasad , Narala Venkateswari , Miryala Sandhyarani , Padarti Vijaya Kumar and Kesana Mohana Lakshmi

A compact UWB-MIMO antenna designed for sub-6 GHz, Ku-band, and millimeter-wave applications with UWB capabilities is proposed. The antenna design consists of two inverted L-shaped MIMO elements with slot etching, deliberately positioned on an FR-4 material substrate, measuring 36 × 18 × 1.6 mm³. Utilizing inverted L-shaped elements and prudently arranged slots on the substrate, the design achieves wideband characteristics. For enhanced isolation, interconnected rectangular slots with a fork shape are etched in the bottom layer, ensuring isolation of less than -25 dB between ports. The proposed design exhibits an impedance bandwidth of approximately 54% within the frequency range of 3 GHz to 40 GHz, making it suitable for sub-6 GHz 5G bands, Ku-band, and millimeter-wave applications. The advantages of compactness and low profile of the proposed design are best suitable for 5G, Ku-band, and millimeter applications with UWB capabilities. The proposed design is successfully fabricated and tested.

Isolation and Bandwidth Enhancement of Compact Wideband MIMO for Sub-6 GHz, Ku-band and Millimeter-wave with UWB Applications

2024-09-23

PIER C

Vol. 148, 71-82, 2024

doi:10.2528/PIERC24062801

download: 54

A Novel Direct Instantaneous Torque Control Strategy of Permanent Magnet-Assisted Switched Reluctance Motor with Zero Voltage Modulation

Chaozhi Huang , Renquan Xiao , Chengyi Gong and Yong Xiao

To reduce large torque ripple in permanent magnet-assisted switched reluctance motors (PMa-SRMs), a novel direct instantaneous torque control (DITC) strategy with zero-voltage modulation is proposed in this paper, where a fixed-frequency pulse width modulation (PWM) is replaced by the conventional DITC hysteresis controller to optimize zero-voltage insertion time through zero-voltage decentralized modulation to minimize switching losses. Control intervals are then divided based on inductance and torque-to-current ratio (TCR) characteristics, with adaptive duty cycle adjustments to enhance torque tracking and reduce ripple. Additionally, the optimal turn-on and turn-off angles are determined by the dung-beetle-optimized back propagation (BP) neural network (DBO-BP) algorithm, which suppresses the torque ripple, lowers phase current peaks, and improves motor efficiency. The feasibility and effectiveness of the proposed method are validated by simulations and experiments with a three-phase 6/20 PMa-SRM.

A Novel Direct Instantaneous Torque Control Strategy of Permanent Magnet-assisted Switched Reluctance Motor with Zero Voltage Modulation

2024-09-19

PIER C

Vol. 148, 61-70, 2024

doi:10.2528/PIERC24061703

download: 55

Investigation of Stator/Rotor Pole Number Combinations and PM Numbers on Variable Flux Leakage PM Machine

Xiping Liu , Ruipan Lu , Yuxin Liu and Wenrui Wang

This paper proposes a variable flux leakage permanent magnet (PM) machine and investigates the impact of slot and pole number combinations on the electromagnetic performance of a variable flux leakage permanent magnet machine (VFL-PMM). The stator armature winding dq-axis magnetic circuit is designed to couple with the PM leakage magnetic circuit by the deliberate establishment of a leakage-guided magnetic barrier and a poly-magnetic barrier on the rotor side. The VFL-PMM with 12s10p-DL (double layers) fractional slot centralized winding (FSCW) serves as an illustrative example of global parametric modelling of the machine. The objective is to optimize the split ratio, average torque, torque ripple, and PM utilization of the machine to obtain the optimum amount of the machine. The relationship between the no-load, on-load characteristics, and variable flux leakage characteristics of 12s8p, 12s10p, 12s14p with double-layer FSCW and 12s10p with single-layer FSCW are studied comparatively. The machines are analyzed and optimized using 2D finite element analysis.

Investigation of Stator/Rotor Pole Number Combinations and PM Numbers on Variable Flux Leakage PM Machine

2024-09-19

PIER C

Vol. 148, 55-60, 2024

doi:10.2528/PIERC24062301

download: 48

A High Isolation Dual-Polarized Base Station Antenna with Wideband Differential Feed

Hua Chen , Quan Wang , Mankang Xue , Xinhui Yang , Ning Huang and Qing Fang

In this paper, a novel stacked wideband differentially feed antenna with dual polarizations is designed for base station. The circular parasitic patch deepens the resonance depth by slotting. Two linear dipoles are placed at ±45° under the circular parasitic patch to reduce the overall size of the antenna. The antenna introduces a cross-shaped differential feed to achieve high port isolation. Finally, the designed antenna is fabricated and tested. The test results show that the differential reflection coefficient |Sdd11| is more than 15 dB. The antenna achieves a differential impedance bandwidth of 53.1% (1.63 GHz-2.8 GHz). The isolation is greater than 42 dB over the entire operating bandwidth. The antenna also has a stable gain of 8.2±0.4 dBi and a half-power beamwidth of 65°±4°.

A High Isolation Dual-polarized Base Station Antenna with Wideband Differential Feed

2024-09-19

PIER C

Vol. 148, 43-54, 2024

doi:10.2528/PIERC24062504

download: 59

Double and Triple-Vector Hybrid Modulation Model Predictive Control Based on Virtual Synchronous Generator

Yang Zhang , Yuwei Meng , Xiuhai Yang , Kun Cao , Sai Zhang and Zhun Cheng

To address the issues of high current harmonic and power ripple in the traditional Finite Control Set Model Predictive Control (FCS-MPC) strategy for virtual synchronous generator system with quasi-Z-source inverter (qZSI-VSG), a double and triple-vector hybrid modulation model predictive control strategy is proposed. This strategy utilizes the inductor current sub-cost function to select the shoot-through state (ST state) or the non-shoot-through state (NST state). When NST state is selected, the voltage vector combinations in the double-vector and the triple-vector are initially established. Then, the voltage vector combinations are reduced from 18 groups to 6 groups by using the vector combination quick selection table. Subsequently, the duty cycle of each voltage vector is then determined based on the value of its cost function, and the voltage vector is re-synthesized. Finally, the predicted values of all control variables are calculated and substituted into the cost function for optimization. Experimental results show that the proposed strategy reduces 48.62% of current harmonic, 50% of active power ripple and 25.53% of capacitor voltage ripple compared to the traditional strategy, which effectively improves the system control performance.

Double and Triple-vector Hybrid Modulation Model Predictive Control Based on Virtual Synchronous Generator

2024-09-17

PIER C

Vol. 148, 31-42, 2024

doi:10.2528/PIERC24071101

download: 100

A Dual-Band MIMO Antenna Based on Multimode for 5G Smartphone Applications

Han Lin , Wenjie Sun , Zhonggen Wang and Wenyan Nie

In order to meet the current demand for 5G smartphone antennas, this paper introduces a six-port dual-band multiple-input multiple-output (MIMO) antenna designed for 5G smartphones. Based on multimode, the antenna achieves multiple band coverage in a limited space, making it of significant practical value in 5G cell phone antenna applications. The antenna features a structure comprising a modified L-shaped patch antenna, a gun-shaped slot in the ground plane, and two small stubs extending from the metal ground. This configuration creates a multimode antenna that is excited by two coupled feed loop modes and two slot modes. The feeder strips, which have been enhanced with L-shaped slots, form tuned branches, enabling the co-excitation of multiple modes. The MIMO system can operate within the frequency range of 3.3-3.8 GHz and 4.4-7.5 GHz (S₁₁ < -6 dB), covering the 5G communication bands including n78 (3.3-3.8 GHz)/n79 (4.4-5.0 GHz) and the LTE Band 46 (5.15-5.925 GHz). Additionally, the antenna exhibits an envelope correlation coefficient of less than 0.18, antenna efficiency ranging from 60% to 93%, and isolation between adjacent antenna elements better than 12.9 dB.

A Dual-band MIMO Antenna Based on Multimode for 5G Smartphone Applications

2024-09-12

PIER C

Vol. 148, 19-30, 2024

doi:10.2528/PIERC24030102

download: 82

A Terahertz Signal Transmission in Plasma Sheath with Different Vehicle Size

Zhikang Chu , Mingyang Mao , Jiawei Xiong , Ziyang Zhao , Rongxin Tang and Kai Yuan

Communication blackout is a serious threat to aerospace engineering. Over the past decade, the terahertz (THz) technology has been considered an effective solution to the blackout problem. However, it is currently unclear that how the size of the vehicle affects the conditions of the THz communication channel within the plasma sheath. In this study, a numerical hypersonic hydradynamical model is introduced to investigate the relationship between THz signal attenuation in the plasma sheaths and the size of the vehicle. The analysis shows that the size of the vehicle significantly influences the structure of the plasma sheath. The thickness of the plasma sheath increases linearly with the size of the vehicle. The maximum electron density in smaller vehicles shows unstable fluctuations, attributed to variations in size causing changes in the flow velocity and mass density, resulting in the variation of pressure distribution. Additionally, with the increase of plasma sheath thickness, the attenuation coefficient of THz signals increases linearly. Therefore, for the vehicles of large sizes, the designs that minimize the thickness of the plasma sheath, such as shaped configurations, are helpful to mitigate the communication blackout.

A Terahertz Signal Transmission in Plasma Sheath with Different Vehicle Size

2024-09-11

PIER C

Vol. 148, 9-18, 2024

doi:10.2528/PIERC24071201

download: 49

Transmission Characterization of Four-Layer PCB Differential Lines Based on Modified Kron's Methodology

Weibing Xiao , Kuangang Fan , Fazhu Zhou , Jizan Zhu and Shuliang Li

This paper addresses the high-frequency signal transmission problem of high-speed differential lines on four-layer printed circuit boards (PCBs). It establishes a mathematical model of high-speed differential lines in conjunction with modified Kron's methodology (MKM), a nontraditional circuit modeling method. The article builds the model through diakoptics of differential lines, then generates the corresponding topology maps, and finally creates the model through tensorial analysis of the network (TAN). The differential line model is simulated and optimized by HFSS. This paper mainly analyzes the influence of differential line spacing and grounding vias on the signal transmission of differential lines. Secondly, it analyzes the problem of multi-group differential line arrangement based on the above work. Finally, the experimental results obtained are consistent with the simulation ones.

Transmission Characterization of Four-Layer PCB Differential Lines Based on Modified Kron's Methodology

2024-09-11

PIER C

Vol. 148, 1-7, 2024

doi:10.2528/PIERC24061306

download: 95

SRA-DGS-NL Based Decoupling Scheme for MIMO Antenna

Revati C. Godi and Rajendra R. Patil

In this paper, a novel decoupling strategy for a MIMO antenna is proposed. This MIMO antenna system consists of two symmetric inverted L shaped antenna elements. To improve the isolation between radiating antenna elements, split ring arrays, neutralisation line and ground slots are employed. The MIMO antenna operates at 6.27 GHz. Neautralization line aids in cancelling the coupling by introducing reverse coupling. Ground slots introduce band-stop characteristic to nullify the coupling effect, and split ring array blocks the electromagnetic coupling reaching the other antenna element. The isolation parameters |S₁₂| and S₂₁ obtained are less than -21 dB. The diversity parameters envelope correlation coefficient and diversity gain are investigated. Envelope correlation coefficient is within acceptable limit. These diversity parameters indicate that good diversity performance is achieved by the proposed MIMO antenna. Measured results are in good agreement with simulated ones. The suggested antenna is appropriate for many wireless applications, including IEEE 802.11 and 802.16 standards, as we deal with the sensitive environment.