PIER C | PIER Journals

2024-11-21

PIER C

Vol. 150, 125-133, 2024

download: 53

Analysis of Inscribed Hexagonal Slot Loaded Antenna for Short Range RFID Reader Applications

Rupanita Das , Tanmay Kumar Das , Ajay Kumar Yadav , Harish Chandra Mohanta , Abdul Kayum Muhammad Zakir Hossain and Ahmed Jamal Abdullah Al-Gburi

This article introduces an inscribed hexagonal-slot square patch antenna developed in the field of RFID technology for reader applications. The proposed structure is energized with one feeding element. This study proposes a high-gain microstrip antenna for ISM band applications at 5.8 GHz. FR4 material is utilized in design and fabrication of the antenna. The resulting design achieves a −10 dB impedance bandwidth of around 3.6% in the ISM band. The proposed design is determined to be compact in comparison to several contemporary designs and has dimensions of 0.43 λ x 0.43 λ x 0.03 λ (λ = wavelength at 5.8 GHz). The measurement reveals that the antenna can operate across the frequency band 5.67 GHz−5.88 GHz having a maximum gain value 4.58 dBi at 5.77 GHz. The satisfaction of the propagation test in different environments and the reading distance value of 2.81 cm at the ISM band supports the application of the structure as a short-range RFID reader.

Analysis of Inscribed Hexagonal Slot Loaded Antenna for Short Range RFID Reader Applications

2024-11-18

PIER C

Vol. 150, 113-124, 2024

doi:10.2528/PIERC24062401

download: 32

Slot Antenna in Cylindrical Coupling Brick for Microwave Brain Imaging

Antonio Cuccaro , Angela Dell'Aversano , Bruno Basile and Raffaele Solimene

In this contribution, two antennas for microwave imaging are described and validated. The first solution is a slot antenna designed when it works a direct contact with human head. However, the air-gap issues and hair layer degrade the antenna performances. These limitations are overcome with the cylindrical brick antenna containing coupling liquid medium. Basically, this antenna consists of a ground plane hosting a wide slot and a microstrip feed line with a fork-like tuning stub inserted within the circular container. Numerical examples show that the proposed antenna exhibits S₁₁ below -10 dB over the selected frequency band from 1 to 2 GHz, in agreement with microwave brain imaging systems. Moreover, the antenna is assessed in terms of transmission coefficients and field penetration. In particular, it is shown that such a feature holds true when the antenna is placed in different positions over the head, when it is located on both the skin and the hair. Experiments on a few real humans confirm the numerical results. The transmission coefficient, which is the only one used in imaging systems to streamline the hardware complexity, is of comparable level of other similar antennas already present in literature. However, the proposed antenna is lighter and smaller in size.

Slot Antenna in Cylindrical Coupling Brick for Microwave Brain Imaging

2024-11-17

PIER C

Vol. 150, 105-112, 2024

doi:10.2528/PIERC24092803

download: 39

Systematic Synthesis of Fully-Planar Antennas Based on Metamaterial-Enhanced Siws for 5G Communications

Vasileios Salonikios , Stamatios A. Amanatiadis and Michalis Nitas

A fully numerical process for the systematic design of fully-planar antennas for 5G communications frequencies is presented, utilizing a metamaterial-enhanced SIW as the basis platform. A combined modal analysis and wave propagation Finite Element modeling is proposed for the accurate design of the waveguiding structure towards its leakage loss minimization. Based on this robust numerical schemes, two different types of fully-planar antennas are designed. A leaky-wave fully-planar two-slot antenna and an H-plane end-fire sectoral horn antenna. Both structures are viable candidates for integration in 5G communications platforms, exhibiting attractive characteristics such as optimized gain and bandwidth, low cost, compactness, and ease of fabrication.

Systematic Synthesis of Fully-planar Antennas Based on Metamaterial-enhanced SIWs for 5G Communications

2024-11-14

PIER C

Vol. 150, 89-95, 2024

doi:10.2528/PIERC24081605

download: 49

Grating Lobe Performance Improvement of an Arbitrarily Spaced Array of through -the-Wall Imaging Radars Using Time Reversal Techniques

Paramananda Jena and Kedar Nath Sahu

This paper presents a Time Reversal (TR) application to mitigate the grating lobes of an arbitrarily spaced array for a through-the-wall imaging radar (TWIR). Analytical modeling and simulation of array of arbitrarily located elements with (i) conventional and (ii) time reversal beamforming have been carried out. The results are analysed and compared. The array is used to image a target using the multipaths in a typical TWIR environment. The Time Reversal technique as spatial correlator improves the performance of the arbitrarily located array which is akin to the array thinning of conventional array processing. It is demonstrated that the TR beamforming can mitigate the grating lobes of large sparse array with a fewer elements. The performance metrics are captured in terms of Side Lobe Levels (SLLs) and image radius. The SLL performance and image radius are benchmarked for different configurations of array. It is shown that a fewer-element sparse array with Time Reversal is feasible for practical TWIRs.

Grating Lobe Performance Improvement of an Arbitrarily Spaced Array of Through-the-wall Imaging Radars Using Time Reversal Techniques

2024-11-14

PIER C

Vol. 150, 81-88, 2024

doi:10.2528/PIERC24051802

download: 36

4 × 4 RHCP Array Antenna Base on LTCC and Quartz Interposer

Hao Wei , Wei Han and Naibo Zhang

This paper designs, simulates, fabricates, and measures a right hand circular polarization (RHCP) array antenna, which is based on a low temperature co-fired ceramic (LTCC) and quartz interposer. The proposed array antenna consists of $4\times 4$ antenna cells, and axis ratio of the antenna element in array antenna can be optimized after array expansion. This RHCP antenna's wide frequency band and good axial ratio band are obtained by the stacked patches. The thickness of the proposed antenna without fixed structure is about 1.7 mm, and it is realized by a LTCC substrate with 14 layers and a quartz interposer with the thickness of 0.254 mm. The measured results demonstrate that, for the operated frequency band of 17.5 GHz~21.5 GHz, the VSWR of the proposed antenna is better than 1.7, the RHCP gain more than 15.5 dB, the axial ratio less than 3 dB, and the size of the proposed antenna without connectors is 29.6 mm × 29.6 mm × 1.7 mm.

4 × 4 RHCP Array Antenna Base on LTCC and Quartz Interposer

2024-11-12

PIER C

Vol. 150, 69-80, 2024

doi:10.2528/PIERC24070901

download: 52

A Current Sensorless Interval Torque Ripple Suppression Method for Permanent Magnet Assisted-Switched Reluctance Motor

Chengyi Gong , Junxin Xu , Renquan Xiao , Chaozhi Huang , Xiaobo Liu and Yong Xiao

The conventional DITC strategy for switched reluctance motor relies on current for control, while the use of current sensors increases the complexity of the system, and the torque ripple in the two-phase exchange region of the conventional DITC strategy is too large. To solve the above problems, a current sensorless interval torque control (CSITC) method is proposed. Initially, the equivalence between torque and acceleration control is established, replacing the torque loop with an acceleration loop. This forms a dual closed-loop system with the speed control loop, enhancing system stability. Subsequently, the variation of the output torque capacity of phase winding of the motor in each conduction region is analyzed, and combined with the inductive characteristics of the motor windings, the two-phase exchange region is divided into two subregions. Different acceleration hysteresis loop control strategies are adopted for the phase windings in each region, so as to realize the stable output of the motor torque. Finally, a three-phase 6/20 permanent magnet assisted-switched reluctance motor (PMa-SRM) is used for simulation and physical verification. The results show that the method can still achieve the steady state of the motor when only the position sensor is used and effectively reduces the torque ripple in the exchange region.

A Current Sensorless Interval Torque Ripple Suppression Method for Permanent Magnet assisted-Switched Reluctance Motor

2024-11-12

PIER C

Vol. 150, 57-68, 2024

doi:10.2528/PIERC24092505

download: 48

Refinement of Chipless RFID Tags Across Multiple Positions for Improved Recognition Reliability through Machine Learning Techniques

Athul Thomas , Midhun Muraleedharan Sylaja and James Kurian

Chipless RFID technology offers a cost-effective and durable alternative to chipped tags for identification and tracking applications. By eliminating the need for an integrated circuit, chipless tags are cheaper and can withstand harsher environments. This opens doors to not only track items throughout a supply chain or monitor valuable assets, but also integrate basic sensors for functionalities like environmental monitoring or smart agriculture. However, limitations in data capacity, read range, and decoding complexity currently hinder their full potential. This paper explores the application of machine learning techniques to improve the interrogation process and enhance the reliability of chipless Radio Frequency Identification systems. The effectiveness of machine learning in optimising chipless RFID systems hinges on the richness and variety of training data. A robust dataset encompassing diverse tag characteristics, environmental factors, and reader configurations is paramount. Nevertheless, gathering real-world RFID data can be difficult. To address this, a data collection procedure has been specifically designed to gather backscattered information from the chipless tags at multiple orientations and distances. Four binary combinations of a 5-bit RFID tag based on frequency-selective surfaces operating in the 2–8GHz range are considered for generating the database. The dataset is then used to train and validate various classification models, including support vector machine (SVM), k-nearest neighbour (k-NN), Decision Tree (DT), Naive Bayes classifier, and Logistic Regression (LR). The proposed Support Vector Machine model is able to identify the tag at a distance of up to 70 cm from the interrogator, with multiple rotational degrees of freedom.

Refinement of Chipless RFID Tags across Multiple Positions for Improved Recognition Reliability through Machine Learning Techniques

2024-11-10

PIER C

Vol. 150, 47-55, 2024

doi:10.2528/PIERC24090702

download: 85

Flexible Ring Slot Antenna for Optimized 5G Performance in N77 and N78 Frequency Bands for Wearable Applications

Gaurav Kumar Soni , Dinesh Yadav , Ashok Kumar , Chanchal Sharma and Manish Varun Yadav

The growth of 5G communications has created a demand for advanced wearable and flexible antennas due to supporting the high speeds, low latency, and capability of mechanical deformation conditions such as bending and conformability. In this paper, the design and analysis of a defected ground structure (DGS)-based ring slot antenna for N77 (3.3-4.2 GHz) and N78 (3.3-3.8 GHz) frequency bands is demonstrated. The antenna is made of an RT/Duroid 5880 substrate and has a loss tangent (tanδ) of 0.0009 and dielectric constant (ε_r) of 2.2. A DGS-based ring slot microstrip antenna is simulated, tested and experimentally characterized on different body locations (leg, chest, and hand) along with bending, and their results are presented accordingly. The magnitude of S₁₁ (|S₁₁|) of the proposed antenna is -26.81 dB at resonant frequency of 3.45 GHz, with the impedance bandwidth of 22 MHz (3.486 GHz to 3.508 GHz), peak gain of 6.27 dBi, and radiation efficiency of 85.02%. The simulated specific absorption rate (SAR) for 1 g and 10 g human body tissues is 0.263 W/Kg and 0.076 W/Kg, respectively. The total volume of the antenna is 0.58λ₀ × 0.58λ₀ × 0.00595λ₀ (at 3.5 GHz). The proposed antenna is suitable for 5G wearable devices.

Flexible Ring Slot Antenna for Optimized 5G Performance in N77 and N78 Frequency Bands for Wearable Applications

2024-11-06

PIER C

Vol. 150, 37-46, 2024

doi:10.2528/PIERC24071303

download: 41

The Dual-Modality Fusion Imaging Method for EMT and UTT Based on DSCTFusion-ECA

Jinxun Le , Ronghua Zhang , Wenying Fu , Shuqing Jia , Xuefeng Bai and Boyang Li

Dual-modality tomography integrates two different imaging technologies, allowing for the acquisition of more comprehensive sensing data. By combining information from both modalities, the accuracy of final imaging results is enhanced. However, due to the use of different physical sensitive field backgrounds by different measurement modalities, integrating information from different modalities with differing dimensions presents a challenge. To address this issue, a supervised DSCTFusion-ECA deep learning method is proposed. This method consists of four modules: initial imaging, feature extraction, feature fusion, and image reconstruction. In the feature extraction module, dense connections are utilized first to extract shallow cross-modal features, then two dual-branch feature extraction networks are utilized to separately capture modality-specific low-frequency global features and high-frequency local features for both modalities. The performance and robustness of multi-modality tomography can be effectively improved through the extraction of more comprehensive features. In the feature fusion module, Efficient Channel Attention is employed to capture channel dependencies and generate attention weights. The modal complementarity and the representation ability of key features have been enhanced, while avoiding information redundancy, thereby improving the discriminative power of the features. Simulation results show that the proposed network can fully extract and fuse features from EMT and UTT modalities, demonstrating strong robustness and generalization. Compared to the widely used U-Net network in tomography, DSCTFusion-ECA yields better reconstruction results.

The Dual-modality Fusion Imaging Method for EMT and UTT Based on DSCTFusion-ECA

2024-11-06

PIER C

Vol. 150, 27-36, 2024

doi:10.2528/PIERC24092306

download: 60

Design of Frequency Reconfigurable Quadruple Band Notched Ultra-Wideband Antenna

Sunitha Mandava , Silpa Mandava , Bathula Santhi Kiran , Gowrisankar Kalakoti , Manasa Bandlamudi and Chandana Kotha

A miniaturized ultra-wideband (UWB) antenna with quadruple reconfigurable characteristics is proposed in this paper. The first step involves the development of an elementary circular patch antenna of size 28.5 × 28.5 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 inverted U-shaped slots. The antenna has an impedance bandwidth ranges from 3.1 GHz to 12 GHz, with four specific notches located at 3.62 GHz (3.46-3.69 GHz), 3.94 GHz (3.81 GHz-3.94 GHz), 4.3 GHz (4.19 GHz-4.39 GHz), and 4.84 GHz (4.61 GHz-5.05 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, satellite communication uplink C-band, Indian national satellite system, and WLAN. The prototype was constructed and evaluated, with the results from simulation and measurement correlating well.

Design of Frequency Reconfigurable Quadruple Band Notched Ultra-Wideband Antenna

2024-11-05

PIER C

Vol. 150, 17-26, 2024

doi:10.2528/PIERC24070503

download: 62

Controllable Multimode Four-Passband Filter Based on Substrate-Integrated Waveguide

Mingming Gao , Congying Wang , Jingchang Nan , Xinyu Wang and Ya He

A metalized through-hole perturbation structure is proposed to effectively control multiple modes of substrate-integrated waveguide (SIW) filters. The method manipulates six modes (TE₁₀₁, TE₂₀₁, TE₁₀₂, TE₂₀₂, TE₃₀₁, and TE₄₀₁) result in the formation of three passbands. Subsequently, two symmetrical parallel complementary split ring resonators (CSRRs) are introduced without altering the filter's size. These rings generate resonances primarily excited by TE₂₀₁ and TE₁₀₂, allowing the filter to produce a fourth passband. Additionally, extra transmission zeros (TZs) are added, creating a perturbing effect on other modes. This further aids in controlling the resonances of these modes. The filter exhibits flexibility and controllability in terms of center frequency, bandwidth, and transmission zeros. The center frequencies of the four passbands are measured at 7.47 GHz, 9.84 GHz, 11.02 GHz, and 12.65 GHz, with return losses exceeding 18 dB. Additionally, there are six TZs, with the highest frequency point reaching -56.58 dB, indicating good in-band and out-of-band rejection. The measured and simulated results demonstrate satisfactory performance and applicability to multi-channel transmission in radar and satellite communication systems.

Controllable Multimode Four-Passband Filter Based on Substrate-integrated Waveguide

2024-11-05

PIER C

Vol. 150, 9-16, 2024

doi:10.2528/PIERC24081601

download: 39

Differential Filtering Quad-Band Antenna Based on Enhanced Folded-Dipole

Sui Teng Zhang , Hao Ran Zhang and Wen-Tao Li

In this paper, a high-selectivity differential filtering quad-frequency antenna is proposed, consisting of two pairs of parallel enhanced folded dipoles and a diplexer. The diplexer employs unbalanced-to-balanced feeding, enabling the desired frequencies and transmission zero points by adjusting the lengths and distances between the stepped impedance resonators. Moreover, enhanced folded dipoles are arranged on either side of the substrate, which can feature a more compact structure and achieve multi-band radiation performance. For verification, a prototype of the proposed differential filtered quad-band antenna is fabricated and measured, having a size of 80 mm × 94.2 mm × 1 mm (1.10×1.29×0.0137λ_g at 2.53 GHz). Measured results show that the relative impedance bandwidths with |S₁₁| < -10 dB at the center frequencies of 2.53, 2.89, 3.30, and 3.68 GHz are 1.97%, 1.00%, 2.25%, and 2.04%, and the corresponding gains are 4.56, 2.82, 3.93, and 3.43 dBi, respectively, revealing its stable radiation performance and excellent anti-interference ability.

Differential Filtering Quad-band Antenna Based on Enhanced Folded-dipole

2024-11-05

PIER C

Vol. 150, 1-8, 2024

doi:10.2528/PIERC24091401

download: 37

Monopole Antenna Loading Parasitic Metal Pillar Element with Suppression of Beam Upwarping to Improve Omnidirectional Radiation in Broadband

Jiemin Jing , Wen-Quan Cao , Hong Xue , Chuang Wang , Yangkun Zhu , Yixin Tong and Huangshu Zhou

Due to the presence of finite ground, the radiation pattern of a monopole antenna will upwarp, thereby affecting the communication quality in the horizontal direction. Loading parasitic metal pillar elements near monopole antenna is a common beam control method. In this paper, an inverted monopole antenna is used as the source antenna to analyze the effect and band of beam upwarping suppression in wide band. The working principle and parameter analysis of elements are also discussed. This antenna can achieve 1-24°of suppression from 360 to 570 MHz. At the same time, keeping the un-roundness almost unchanged, the horizontal plane gain is increased by 0.53-1.74dB. The omnidirectional pattern is improved, which provides a valuable candidate for vehicle communication.