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15 pages, 3797 KiB

Open AccessArticle

Three-Dimensional Printed Annular Ring Aperture-Fed Antenna for Telecommunication and Biomedical Applications

by Khaled Alhassoon, Yaaqoub Malallah, Fahad N. Alsunaydih and Fahd Alsaleem

Sensors 2024, 24(3), 949; https://doi.org/10.3390/s24030949 - 1 Feb 2024

Cited by 4 | Viewed by 1768

The design of the aperture-fed annular ring (AFAR) microstrip antenna is presented. This proposed design will ease the fabrication and usability of the 3D-printed and solderless 2D materials. This antenna consists of three layers: the patch, the slot within the ground plane as the power transfer medium, and the microstrip line as the feeding. The parameters of the proposed design are investigated using the finite element method FEM to achieve the 50 Ω impedance with the maximum front-to-back ratio of the radiation pattern. This study was performed based on four steps, each investigating one parameter at a time. These parameters were evaluated based on an initial design and prototype. The optimized design of 3D AFAR attained S₁₁ around 17 dB with a front-to-back ratio of more than 30 dB and a gain of around 3.3 dBi. This design eases the process of using a manufacturing process that involves 3D-printed and 2D metallic materials for antenna applications. Full article

(This article belongs to the Special Issue Wearable Antennas and Sensors for Microwave Applications)

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15 pages, 49865 KiB

Open AccessArticle

Pentaband Dual-Polarized Antenna for Multiservice Wireless Applications

by A. Ushasree and Vipul Agarwal

Computation 2023, 11(4), 76; https://doi.org/10.3390/computation11040076 - 8 Apr 2023

Cited by 3 | Viewed by 2040

Abstract

This paper presents a novel design for and an experimental study of a dual-polarized quad-port MIMO antenna. The design achieves resonance at five distinct frequency bands with reduced mutual coupling. The design includes a single annular ring slot, four truncated rectangular corners, and a truncated aperture to improve resonance behavior. The design is then extended to a four-port MIMO antenna by including a ground-plane slit to enhance isolation between antenna elements at the center resonance band. The antenna achieves resonances at 5 distinct bands, ranging from 1.5 to 8.4 GHz, with significant mutual coupling reductions. The resonances of the quad-port pentaband MIMO antenna are achieved at 1.55 GHz (1.5–1.65 GHz), 2.5 GHz (2.4–2.7 GHz), 5.2 GHz (5–5.85), 7.3 GHz (7.1–7.4), and 8.15 GHz (7.9–8.4), with respective mutual coupling reductions of 27 dB, 37 dB, 21 dB, 29 dB, and 21 dB. Additionally, the 3 dB axial ratio bandwidth (ARBW) is observed at 6.5% (1.5–1.6 GHz) and 15% (2.4–2.7 GHz) in 2 distinct bands, and the envelope correlation coefficient and diversity gain are calculated within the specified band range. Experimental measurements of the prototype for the quad-port antenna are conducted, with excellent agreement found between the results and the simulations. Full article

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15 pages, 6991 KiB

Open AccessArticle

Quad-Port Circularly Polarized MIMO Antenna with Wide Axial Ratio

by Vamshi Kollipara and Samineni Peddakrishna

Sensors 2022, 22(20), 7972; https://doi.org/10.3390/s22207972 - 19 Oct 2022

Cited by 17 | Viewed by 2675

Abstract

This article studies a quad-port multi-input-multi-output (MIMO) circularly polarized antenna with good isolation properties. Using characteristic mode analysis (CMA), the first six distinct modes of the asymmetric square slot with an inverted L-strip are analyzed. In this study, modal parameter extraction is carried out for circular polarization (CP) radiation. A simple annular ring microstrip feed is excited to obtain broadband CP based on CMA. The single-unit feeding structure is replicated orthogonally four times to achieve a CP MIMO antenna. This antenna provides port isolation of more than 21 dB without the use of an additional decoupling element. The quad-port CP-MIMO antenna is simulated with a total dimension of 50 × 50 mm². The antenna attains impedance matching (S₁₁ < −10 dB) from 5.37 GHz to beyond 11 GHz with an axial ratio bandwidth (ARBW) of 4.65 GHz (5.61 GHz to 10.26 GHz). The peak realized gain of the MIMO antenna is measured at 5.69 dBi at 8.4 GHz. Additionally, the diversity performance parameters of the MIMO structure are computed. The advantages of the proposed structure have been evaluated by comparing it to previously reported MIMO structures. A prototype of the MIMO structure measurements was found to match the simulation results. Full article

(This article belongs to the Special Issue Massive MIMO Systems for High-Resolution Localization, Radar, and Imaging Systems: State-of-the-Art, Perspectives and Applications)

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14 pages, 1736 KiB

Open AccessArticle

Wideband mm-Wave Hemispherical Dielectric Resonator Antenna with Simple Alignment and Assembly Procedures

by Meshari D. Alanazi and Salam K. Khamas

Electronics 2022, 11(18), 2917; https://doi.org/10.3390/electronics11182917 - 14 Sep 2022

Cited by 9 | Viewed by 3031

Abstract

A wideband hemispherical dielectric resonator antenna (DRA) with enhanced gain is proposed for a frequency band of 20 to 28 GHz. The precise alignment and assembly of the DRA represent key challenges at such frequencies that were addressed using three approaches: the first was based on outlining the DRA position on the ground plane, the second involved creating a groove in the compound ground plane in which the DRA is placed, and the third was based on the 3D-printing of the DRA on a perforated substrate. In all cases, the same DRA was utilized and excited in a higher-order mode using an annular ring slot. The high gain was achieved by exciting a higher-order mode, and the wideband was obtained by merging the bandwidths of the two excited modes. The alignment methods used expedite the DRA prototyping by saving substantial time that is usually spent in adjusting the DRA position with respect to the feeding slot. The proposed configurations were measured, with an impedance bandwidth of 33.33% and a maximum gain of 10 dBi observed. Close agreement was achieved between the measured and simulated results. Full article

(This article belongs to the Special Issue Antennas in the 5G System, Volume II)

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9 pages, 1909 KiB

Open AccessArticle

Computational Analysis of a 200 GHz Phased Array Using Lens-Coupled Annular-Slot Antennas

by Peizhao Li, Yu Shi, Yijing Deng and Lei Liu

Appl. Sci. 2022, 12(3), 1407; https://doi.org/10.3390/app12031407 - 28 Jan 2022

Cited by 1 | Viewed by 2350

Abstract

We report the design, simulation, and analysis of a THz phased array, using lens-coupled annular-slot antennas (ASAs) for potential beyond 5G or 6G wireless communications. For a prototype demonstration, the ASA employed was designed on a high resistivity Si substrate with a radius of 106 μm, and a gap width of 6 um for operation at 200 GHz. In order to achieve higher antenna gain and efficiency, an extended hemispherical silicon lens was also used. To investigate the effect of the silicon lens on the ASA phased array, a 1 × 3 array and 1 × 5 array (the element distance is 0.55λ) were implemented with a silicon lens using different extension lengths. The simulation shows that for a 1 × 3 array, a ±17° scanning angle with an about −10 dB sidelobe level and 11.82 dB gain improvement (compared to the array without lens) can be achieved using a lens radius of 5000 μm and an extension length of 1000 μm. A larger scanning angle of ±31° can also be realized by a 1 × 5 array (using a shorter extension length of 250 μm). The approach of designing a 200 GHz lens-coupled phased array reported here is informative and valuable for the future development of wireless communication technologies. Full article

(This article belongs to the Special Issue 5G and Beyond Fiber-Wireless Network Communications)

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15 pages, 1719 KiB

Open AccessArticle

Efficient Holographic Focusing Metasurface

by Vinay R. Gowda, Mohammadreza F. Imani, Timothy Sleasman and David R. Smith

Electronics 2021, 10(15), 1837; https://doi.org/10.3390/electronics10151837 - 30 Jul 2021

Cited by 7 | Viewed by 3334

Abstract

We present the design and experimental demonstration of an efficient holographic metasurface aperture that focuses microwaves in the Fresnel zone. The proposed circular structure consists of two stacked plates with their periphery terminated in a conductive layer. Microwaves are injected into the bottom plate, which forms the feed layer, and are coupled to the top holographic metasurface layer via an annular ring. This coupling results in an inward traveling cylindrical wave in the top layer, which serves as the reference wave for a hologram. The radiating elements consist of a slot pair with their orientations designed to couple efficiently with the cylindrical reference wave while maintaining a linearly polarized focused beam. A general condition on the slot pairs radiated power is proposed to ensure low sidelobe level (SLL) and is validated with full-wave simulation. An aperture that is 20 cm in diameter, operates at 20 GHz in the K-band frequency, and forms a diffraction-limited focal spot at a distance of 10 cm is experimentally demonstrated. The proposed near-field focusing metasurface has high antenna efficiency and can find application as a compact source for Fresnel-zone wireless power transfer and remote sensing schemes. Full article

(This article belongs to the Special Issue Wireless Power/Data Transfer, Energy Harvesting System Design, Volume II)

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17 pages, 10980 KiB

Open AccessArticle

Design of a Multi-Band Microstrip Textile Patch Antenna for LTE and 5G Services with the CRO-SL Ensemble

by Carlos Camacho-Gomez, Rocio Sanchez-Montero, Diego Martínez-Villanueva, Pablo-Luís López-Espí and Sancho Salcedo-Sanz

Appl. Sci. 2020, 10(3), 1168; https://doi.org/10.3390/app10031168 - 9 Feb 2020

Cited by 23 | Viewed by 5288

Abstract

A textile multi-band antenna for LTE and 5G communication services, composed by a rectangular microstrip patch, two concentric annular slots and a U-Shaped slot, is considered in this paper. In the ground plane, three sleeved meanders have been introduced to modify the surface current distribution, leading to a bandwidth improvement. The U-Shaped slot, the dual circular slots, and the meanders shape have been optimized by means of the Coral Reefs Optimization with Substrate Layer algorithm (CRO-SL). This population-based meta-heuristic approach is a kind of ensemble algorithm for optimization (multi-method), in which different search operators are considered within the algorithm. We show that the CRO-SL is able to obtain a robust multi-band textile antenna, including LTE and 5G frequency bands. For the optimization process, the CRO-SL is guided by means of a fitness function obtained after the antenna simulation by a specific simulation software for electromagnetic analysis in the high frequency range. Full article

(This article belongs to the Special Issue Passive Planar Microwave Devices )

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