PIER Letters | PIER Journals

2025-03-16

PIER Letters

Vol. 125, 67-73, 2025

doi:10.2528/PIERL25012002

download: 526

Machine Learning Assisted Intelligent Antenna Parameters Estimation Using EOLRKC and SFIS Algorithms

Rajendran Ramasamy, Maria Anto Bennet and Abbas Ali Farithkhan

In this research, the optimization of antenna parameters for the Vivaldi antenna, Inverted F antenna, and Probe Feed Microstrip Patch antenna was carried out using EOLRKC and the Sugeno Fuzzy Inference System (SFIS) machine learning techniques. The research explores numerical and conventional antenna design methods to understand the necessary concepts comprehensively. After a thorough analysis, an intelligent model for antenna selection recommends the best antenna based on various performance metrics evaluated with the Enhanced Logistic Regression Kernel Classifier. Additionally, the geometric properties of the antenna are discussed, and the SFIS is developed by integrating five primary learners to maximize the potential of each learner type. The EOLRK Classifier classifies antennas into three groups: Vivaldi, Inverted F, and Probe Feed Microstrip Patch, while SFIS determines the optimal parameters for antenna size. The accuracy of the EOLRK Classifier is assessed, while the performance of the Sugeno FIS is evaluated using MSE and MAPE. The proposed methodology achieves a MAPE below 4% and an accuracy exceeding 99%, demonstrating exceptional performance in parameter prediction and antenna classification. Implementing these methods has the potential to enhance innovative antenna design practices significantly.

Machine Learning Assisted Intelligent Antenna Parameters Estimation Using EOLRKC and SFIS Algorithms

2025-03-12

PIER Letters

Vol. 125, 59-66, 2025

doi:10.2528/PIERL25010105

download: 451

Wideband Circularly Polarized Inverted Cup Shaped Hybrid Dielectric-Resonator Antenna Over an Asymmetric Jerusalem Cross-Based Metasurface

Naresh Kumar Darimireddy, Rajasekhar Nalanagula, Runa Kumari, Dunya Zeki Mohammed, Zahriladha Zakaria and Ahmed Jamal Abdullah Al-Gburi

This article introduces a Circularly-Polarized (CP) inverted cup-shaped Hybrid Cylindrical-Dielectric-Resonator-Antenna (HCDRA) combined with an asymmetric Jerusalem cross unit-cell based metasurface (MTS). The antenna, designed for use in the 5G n-79 NR band (4400-5000 MHz) and IEEE 802.11n-WLAN (5 GHz) applications, features a unique disturbed coax-feed mechanism at the edge of cylindrical DR and an asymmetric MTS that boosts the circular polarization within the DR antenna. The antenna's E-field and parametric analysis provide evidence of CP radiation. The proposed HCDRA achieves impressive S₁₁ and Axial-Ratio (AR) bandwidths of 2.1 GHz and 740 MHz, with a maximum gain of 6.825 dBic. The overall gain obtained is consistently more than 5.5 dBic across the entire bandwidth of the HCDRA. The fabricated HCDRA is tested in an anechoic chamber, and the obtained practical results closely matched the simulation outcomes, confirming the performance of the proposed design.

Wideband Circularly Polarized Inverted Cup Shaped Hybrid Dielectric-resonator Antenna Over an Asymmetric Jerusalem Cross-based Metasurface

2025-03-12

PIER Letters

Vol. 125, 51-57, 2025

doi:10.2528/PIERL25011701

download: 553

EBG-Based Low Profile Corrugated Antenna for 5G Applications in Sub-6 GHz Spectrum

Hema Raut, Saffrine Kingsly, Sangeetha Subbaraj and Rajeshwari Malekar

The paper describes a two-layer low-profile antenna design suitable for sub-6 GHz communications that operates at 5.8 GHz. The proposed antenna is integrated with a periodic plus-shaped EBG structure to obtain gain and bandwidth enhancement. The realized gains of the prototype with and without periodic structure are 3.48 dBi and 2.4 dBi, respectively. Additionally, it is observed that the measured bandwidth of the antenna structure at 5.75 GHz with periodic structure is 230 MHz, while without periodic structure it is 150 MHz, which accounts for 35% bandwidth enhancement. The simulated and measured results validate that the proposed compact antenna prototype is a suitable candidate for sub-6 GHz application in the 5G spectrum.

2025-03-12

PIER Letters

Vol. 125, 43-50, 2025

doi:10.2528/PIERL24121204

download: 420

Quad-Port Staircase U-Shaped Wideband MIMO Antenna for 5G New Radio Applications

Sanket Nirmal, Sumit Kumar and Richa Chandel

This article introduces a quad-port Multiple Input Multiple Output (MIMO) staircase U-shaped wideband antenna for a 5G New Radio (NR) wireless. The miniaturization of the configuration is achieved with a staircase U-shaped radiating element, and an I-shaped stub etched with rectangular strips between radiating elements provides enhanced isolation. The measured bandwidth of 4.5 GHz is obtained with an isolation, radiation efficiency, and gain above 17 dB, 80%, and 6.5 dB respectively. Certain parameters, such as envelope correlation coefficient (ECC), diversity gain (DG), mean effective gain (MEG), channel capacity loss (CCL), and total active reflection coefficient (TARC), are also evaluated to ensure that the designed MIMO system adheres to its requirements. Hence, the suggested antenna suits the 5G New Radio applications.

Quad-port Staircase U-shaped Wideband MIMO Antenna for 5G New Radio Applications

2025-02-23

PIER Letters

Vol. 125, 37-41, 2025

doi:10.2528/PIERL25010402

download: 433

Novel Compact Wideband Bandpass Filters with High Upper Stopband Rejection Featuring a Quadruple-Mode Resonator

Chuan Shao, Rong Cai, Xinnai Zhang and Kai Xu

In this letter, a novel, compact bandpass filter architecture that leverages a quadruple-mode stepped impedance resonator (SIR) is introduced. This design is predicated on the principles of odd-even-mode analysis, which has been meticulously applied twice to elucidate the resonator's operational dynamics. The distinct boundary conditions inherent to the odd-odd and even-odd degenerate modes result in their splitting, a phenomenon that is pivotal to the filter's performance characteristics. The equivalent circuits representing the quadruple modes function as quarter-wavelength SIRs, a design choice that inherently confers a compact form factor upon the resonator. This is achieved without compromising the filter's functionality, as each mode contributes to the overall filtering response in a manner that is both efficient and space-saving. Furthermore, the filter is characterized by a 20-dB stopband rejection that extends up to 6.9 GHz, which corresponds to 3.8 times of the fundamental frequency (f₀). This outstanding stopband performance is a testament to the design's effectiveness in attenuating unwanted signals while maintaining a compact footprint.

Novel Compact Wideband Bandpass Filters with High Upper Stopband Rejection Featuring a Quadruple-mode Resonator

2025-02-16

PIER Letters

Vol. 125, 33-36, 2025

doi:10.2528/PIERL24112307

download: 283

Lensing by a Single Interface: Perfect Focus Point Rather Than a Drain Point

Leonid A. Pazynin, Kostyantyn Sirenko and Vadym Pazynin

An exact analytical solution is obtained for the problem of finding the field of a linear electric current located near the interface between half-spaces filled with ordinary and perfectly matched double-negative media. To achieve this, a novel approach is introduced that, for the first time, enabled the correct analytic continuation of the function describing the field into the entire half-space filled with a double-negative medium. The analysis of this solution shows that the current source field, upon reaching the point of perfect focusing, passes through it and then moves off to infinity, rather than disappearing at that point, as claimed in earlier works.

Lensing by a Single Interface: Perfect Focus Point Rather Than a Drain Point

2025-02-06

PIER Letters

Vol. 125, 25-31, 2025

doi:10.2528/PIERL24121804

download: 490

A Dual-Polarized Microstrip Patch Antenna with High Port Isolation Based on AMC Surface

Dalong Xu, Wenbo Li, Yan Wang, Hao Wang and Jianyin Cao

A high port isolation dual-polarized microstrip patch antenna based on artificial magnetic conductor (AMC) surface is proposed in this paper. The antenna is composed of two stacked patches and H-shaped coupled slots with improved impedance matching bandwidth. The feed network is composed of two orthogonal microstrip feed lines for dual polarizations, and metallic vias are arranged around them to improve the port isolation. The AMC surface is designed and loaded below the feed lines. The electric field coupling between the feeding slots on the ground are reduced, and the port isolation is greatly improved. The simulated results show that the proposed antenna has a port isolation better than 48 dB and a cross-polarization level of -26 dB over the frequency of 9.3-9.5 GHz. Moreover, based on zero-reflection phase characteristic of the AMC, the profile of the antenna is reduced to 7.3 mm (0.23λ₀，λ₀ is the wavelength at 9.4 GHz). A prototype is fabricated to verify the analysis of proposed antenna. The measured results indicate that a high port isolation better than 44 dB and a cross-polarization level lower than -22 dB are achieved. The maximum gain is higher than 6.98 dBi and 6.5 dBi for the vertical and horizontal polarizations, respectively. With the advantages of high port isolation and low profile, this antenna offers a good candidate for weather radar applications.

A Dual-polarized Microstrip Patch Antenna with High Port Isolation Based on AMC Surface

2025-01-28

PIER Letters

Vol. 125, 17-23, 2025

doi:10.2528/PIERL25010204

download: 381

A Novel Wideband Reflectionless Filtering Patch Antenna

Shuai Gao, Zhongbao Wang, Hongmei Liu and Shao-Jun Fang

In this paper, a novel wideband reflectionless filtering patch antenna is proposed. The antenna consists of a filtering patch and an absorption network. The filtering patch includes an E-shaped radiator and two T-shaped radiators. The E-shaped radiator introduces a radiation null, which greatly improves lower-band edge selectivity. The T-shaped radiators introduce an additional radiation null, effectively increasing the filtering performance in the upper stopband. For the absorption network, a quarter-wavelength coupled-line section with two 200-ohm resistors and four short-circuited three-quarter-wavelength transmission lines are used to achieve reflectionless characteristics. To demonstrate the design, an antenna prototype with a center frequency of 3.5 GHz is fabricated and measured. Measurement results manifest that the input reflectionless bandwidth is 63.5% from 2.56 to 4.94 GHz with an antenna gain of 5.8 dBi. At 3.02 and 3.91 GHz, two radiation nulls are also obtained. The lower and upper stopband suppression levels are 18.1 and 14.5 dB, respectively.

2025-01-26

PIER Letters

Vol. 125, 9-15, 2025

doi:10.2528/PIERL24121805

download: 471

CPW-Fed Minkowski Island Fractal Slot Antenna for Wideband Application

Vanilakshmi Venugopal, Achari P. Abhilash, Rohith K. Raj and Thomaskutty Mathew

This paper proposes a CPW-fed wideband slot antenna with a modified Minkowski fractal island geometry. The antenna comprises a CPW-fed monopole placed within a modified Minkowski fractal island slot. The resonance introduced by the fractal slot combines with the monopole's resonance, resulting in an expanded operational frequency range. The interaction between the monopole and the fractal slot significantly broadens the bandwidth. Return loss measurements confirm a wide bandwidth extending from 2.27 GHz to 7.91 GHz, achieving a fractional bandwidth of 111% covering WLAN, WiMAX, Wi-Fi, and 5G sub-6 GHz bands.

CPW-fed Minkowski Island Fractal Slot Antenna for Wideband Application

2025-01-23

PIER Letters

Vol. 125, 1-7, 2025

doi:10.2528/PIERL24112001

download: 474

High Gain Dual-Frequency Dual-Circularly Polarized Fabry Perot Resonant Cavity Antenna for Ku Band

Wei Luo, Xiaoxue Wang, Xin He and Yuqi Yang

To explore higher-performance satellite communication antennas, a dual-frequency dual-circularly polarized antenna based on a Fabry-Perot (F-P) resonant cavity is proposed in this letter. An artificial magnetic conductor (AMC) is loaded onto the resonant cavity as a partial reflection surface (PRS) to reduce the profile. The electromagnetic (EM) waves from the feeder are reflected multiple times within the cavity and subsequently superimposed in phase, thereby enabling dual-frequency operation and high gain. Right-handed circularly polarized (RHCP) and left-handed circularly polarized (LHCP) waves are respectively generated in the lower and higher frequency bands by incorporating a dual-frequency polarization conversion surface (PCS). Two rectangular microstrip patch antennas with a simple feeding network are employed as the feeder for RHCP and LHCP, respectively. The measurement results show that the operating bandwidth is 4.77% (12.47-13.08 GHz) for the low-frequency band and 5.36% (16.51-17.42 GHz) for the high-frequency band. The maximum gains of 14.91 dBi and 14.33 dBi are achieved for the lower and higher frequency bands, respectively. The proposed antenna fulfills the requirements of the frequency division duplex satellite communication system, providing a promising candidate for ground equipment in high-speed satellite Internet applications.