Resonator Antenna Research Articles

Advanced Dielectric Resonator Antenna Technology for 5G and 6G Applications.

We review dielectric resonator antenna (DRA) designs. This review examines recent advancements across several categories, specifically focusing on their applicability in array configurations for millimeter-wave (mmW) bands, particularly in the context of 5G and beyond 5G applications. Notably, the off-chip DRA designs, including in-substrate and compact DRAs, have gained prominence in recent years. This surge in popularity can be attributed to the rapid development of cost-effective multilayer laminate manufacturing techniques, such as printed circuit boards (PCBs) and low-temperature co-fired ceramic (LTCC). Furthermore, there is a growing demand for DRAs with beam-steering, dual-band functions, and on-chip alignment availability, as they offer versatile alternatives to traditional lossy printed antennas. DRAs exhibit distinct advantages of lower conductive losses and greater flexibility in shapes and materials. We discuss and compare the performances of different DRA designs, considering their material usage, manufacturing feasibility, overall performance, and applications. By exploring the pros and cons of these diverse DRA designs, this review provides valuable insights for researchers in the field.

High gain and high-efficiency compact resonator antennas based on spoof surface plasmon polaritons

Abstract We proposed a high gain high-efficiency compact metallic resonator antenna operating at even-mode meander line spoof surface plasmon polaritons (MLSSPPs). The high radiation efficiency is caused by the bulk of fields crowded in lossless air near the antenna rather than in lossy dielectric as in conventional dielectric resonator antennas (DRAs). The proposed antenna also exhibits compact size because of its high effective refractive index. A reliable equivalent circuit model is proposed for the design of the resonator antenna with basic mode of half wavelength resonant mode. As an example, a meander-line SSPP antenna is designed, fabricated and measured. Both the simulated and measured results show the advantages of high efficiency and compact volume. In addition, the antenna achieves higher gain and wider relative bandwidth per wavelength cube volume compared with its counterparts. This method provides a good alternative for designing DRAs.

Effective modeling of metasurface‐loaded circularly polarized dielectric resonator‐based MIMO antenna for sub‐6.0‐GHz band using machine learning algorithms

SummaryIn this article, a dual‐port dielectric resonator antenna (DRA) is modeled using machine learning (ML) algorithms, that is, deep neural network (DNN), random forest, and XGBoost. The unique properties of the proposed article are as follows: (i) Two different diversity techniques, that is, pattern (with the help of metallic wall) and polarization (mirror image of the aperture), improve the isolation value between the ports; (ii) ML algorithms are used to optimize and predict the reflection coefficient as well as mutual coupling of the proposed antenna. The accuracy of ML algorithms is verified by using the HFSS EM simulator and experimental validation. Error is less than 1%–2% between the value predicted from ML algorithms and HFSS/experimental results. The proposed design is working well in between 2.4 and 4.02 GHz with a 3‐dB axial ratio from 2.84 to 2.95 GHz. All these features make the radiator employable to the sub‐6.0‐GHz frequency band.

Tesla-class single-cycle terahertz magnetic field pulses generated with a spiral-shaped metal microstructure

Abstract We study the terahertz (THz) magnetic field pulse enhanced by a spiral-shaped antenna resonator (SAR). We deposit the SAR on the surface of a terbium-gallium-garnet crystal, which has a large Verdet constant, and measure the Faraday rotation angle for strong THz pulse excitation by magneto-optical sampling (MOS) with near-infrared light. The determined magnetic field strength and field-enhancement spectrum are consistent with the theoretical predictions. This first report of the detection of the magnetic field of a Tesla-class picosecond pulse by magneto-optical sampling is expected to be useful in research on the control of magnetization in spintronic devices.

Multi-objective hybrid split-ring resonator and electromagnetic bandgap structure-based fractal antennas using hybrid metaheuristic framework for wireless applications

Design closure and parameter optimisation are crucial in creating cutting-edge antennas. Antenna performance can be improved by fine-tuning preliminary designs created using theoretical considerations and rough dimension adjustment via supervised parameter sweeps. This paper introduces a frequency reconfigurable antenna design that can operate at 28/38 GHz frequencies to meet FCC and Ofcom standards for 5G applications and in the 18 GHz frequency band for K-band radar applications. A PIN diode is used in this design to configure multiple frequency bands. The antenna has a modified rectangular patch-like structure and two optimised plugins on either side. The study that is being presented focuses on maximising the parameters that are subject to optimisation, including length (Ls), width (Ws), strip line width (W1), and height (ht), where the antenna characteristic parameters such as directivity is tuned by a hybrid optimisation scheme called Elephant Clan Updated Grey Wolf Algorithm (ECU-GWA). Here, the performance of gain and directivity are optimally attained by considering parameters such as length, width, ground plane length, width, height, and feed offsets X and Y. The bandwidth of the proposed antenna at − 10 dB is 0.8 GHz, 1.94 GHz, and 7.92 GHz, respectively, at frequencies 18.5 GHz, 28.1 GHz, and 38.1 GHz. Also, according to the simulation results, in the 18 GHz, 28 GHz, and 38 GHz frequencies S11, the return loss is − 60.81 dB, − 56.31 dB, and − 14.19 dB, respectively. The proposed frequency reconfigurable antenna simulation results achieve gains of 4.41 dBi, 6.33 dBi, and 7.70 dBi at 18.5 GHz, 28.1 GHz, and 38.1 GHz, respectively. Also, a microstrip quarter-wave monopole antenna with an ellipsoidal-shaped complementary split-ring resonator-electromagnetic bandgap structure (ECSRR-EBG) structure has been designed based on a genetic algorithm having resonating at 2.9 GHz, 4.7 GHz, 6 GHz for WLAN applications. The gain of the suggested ECSRR metamaterial and EBG periodic structure, with and without the ECCSRR bow-tie antenna. This is done both in the lab and with numbers. The measured result shows that the ECSRR metamaterial boosts gain by 5.2 dBi at 5.9 GHz. At 5.57 GHz, the two-element MIMO antenna achieves its lowest ECC of 0.00081.

Capturing near-field circular dichroism enhancements from far-field measurements

Molecular circular dichroism (CD) spectroscopy faces significant limitations due to the inherent weakness of chiroptical light-matter interactions. In this view, resonant optical antennas constitute a promising solution to this problem, since they can be tuned to increase the CD enhancement factor, fCD, a magnitude describing the electromagnetic near-field enhancement of scatterers associated with a given helicity. However, an exact analytical expression of fCD remains elusive. Here, we derive an exact multipolar expansion of fCD, which is valid to deduce the integrated near-field CD enhancements of chiral molecules in the presence of scatterers of any size and shape under general illumination conditions. Our exact analytical findings extend previous approximate expressions of fCD that are restricted to the dipolar regime. In addition to this, and based on our exact analytical findings, we show that the near-field fCD factor can be related to magnitudes that can be computed in the far field, i.e., the scattering cross-section and the helicity expectation value. Strikingly, we show that in the case of lossless cylindrically symmetric samples, the near-field fCD factor can be inferred experimentally only from two far-field measurements at specific scattering angles. Our contribution paves the way for the experimental characterization of devices capable of enhancing molecular CD spectroscopy from far-field measurements. Published by the American Physical Society 2024

Miniaturized Laminated Resonator Antenna Array Loaded With Periodic Irises in LTCC

Miniaturized Laminated Resonator Antenna Array Loaded With Periodic Irises in LTCC

Dual‐mode dielectric resonator antenna design with stub‐loaded feeding slot

AbstractA dual‐mode dielectric resonator antenna based on a microstrip line‐slot coupling feed, operating in both the GMS‐900 and GMS‐1800 frequency bands, is presented. The antenna structure consists of a rectangular dielectric substrate and a cylindrical dielectric resonator, which is fed by a microstrip line‐slot coupling. The cylindrical resonant cavity and the dual‐stub coupling slot are designed so that the HEM111 and HEM311 modes are excited simultaneously, resulting in resonance at the two desired frequency points. The gain of the antenna is 3.74 and 7.63 dBi at 0.9 and 1.8 GHz respectively, and the efficiency of the antenna is greater than 70% in both operating bands.

Design of Self-Decoupled Circularly Polarized MIMO Dielectric Resonator Antenna Arrays Based on Polarization Orthogonality

Design of Self-Decoupled Circularly Polarized MIMO Dielectric Resonator Antenna Arrays Based on Polarization Orthogonality

Dielectric Resonator Antennas for RF Energy-Harvesting/Wireless Power Transmission Applications: A state-of-the-art review

This article presents an overview of dielectric resonator (DR)-based sensing elements and their applications in RF energy-harvesting (RFEH) and wireless power transmission (WPT) systems. With increased wireless applications, the demand for electrical energy goes up, thereby enabling the development of various energy sources. RF energy is widely available and the most efficient energy source. Although DR antennas (DRAs) have been studied extensively in the last few decades, they have not been employed in RFEH and WPT applications. The intention of the proposed article is 1) to provide an overview of the DRA for RFEH and WPT applications; 2) to accommodate various performance enhancement approaches for the DRA; and 3) to highlight the research gap for developing a complete rectenna system that helps future researchers. We believe that this survey may help the DRA.

Radiation Patterns of RF Wireless Devices Implanted in Small Animals: Unexpected Deformations Due to Body Resonance.

One challenge in designing RF wireless bioelectronic devices is the impact of the interaction between electromagnetic waves and host body tissues on far-field wireless performance. In this article, we investigate a peculiar phenomenon of implantable RF wireless devices within a small-scale host body related to the deformation of the directivity pattern. Radiation measurements of subcutaneously implanted antennas within rodent cadavers show that the direction of maximum radiation is not always identical with the direction to the closest body-air interface, as one would expect in larger-scale host bodies. For an implanted antenna in the back of a mouse, we observed the maximum directivity in the ventral direction with 4.6 dB greater gain compared to the nearest body-air interface direction. Analytic analysis within small-scale spherical body phantoms identifies two main factors for these results: the limited absorption losses due to the small body size relative to the operating wavelength and the high permittivity of the biological tissues of the host body. Due to these effects, the entire body acts as a dielectric resonator antenna, leading to deformations of the directivity pattern. These results are confirmed with the practical example of a wirelessly powered 2.4-GHz optogenetic implant, demonstrating the significance of the judicious placement of external antennas to take advantage of the deformation of the implanted antenna pattern. These findings emphasize the importance of carefully designing implantable RF wireless devices based on their placements and relative electrical dimensions in small-scale animal models.

A Review on Dielectric Resonator Antennas: Past and Present

A Review on Dielectric Resonator Antennas: Past and Present

Jeans Substrate Based Circularly Polarized Wearable Dielectric Resonator Antenna

Jeans Substrate Based Circularly Polarized Wearable Dielectric Resonator Antenna

Optimizing the geometry of a cylindrical dielectric resonator antenna (CDRA) in combination with the design of a microstrip patch antenna to improve antenna efficiency.

Optimizing the geometry of a cylindrical dielectric resonator antenna (CDRA) in combination with the design of a microstrip patch antenna to improve antenna efficiency.

Dodecahedron lattice of rattling phenomenon, and microwave dielectric properties of yttrium aluminum garnet ceramics and its application verification for Wifi6E/7 patch and 6G resonant antennas

In garnet phase ceramics Y2.9M0.1Al4.9Si0.1O12 (M = Mg2+, Co2+, Zn2+, Mn2+, Ca2+, Sr2+, Ba2+), rattling effects occur when M = Mg2+, Co2+, Zn2+, Mn2+ ions with smaller ionic radius (<1Å) occupy the dodecahedron lattice lattices. This results in an abnormally high dielectric constant, in contrast to the larger ionic radius (>1 Å) of M = Ca2+, Sr2+ and Ba2+, which deviate from the theoretical values calculated using the Clausius-Mosotti formula according to each ion’s polarizability. The optimal microwave dielectric properties for Y2.9Mg0.1Al4.9Si0.1O12 was obtained by sintering at 1575 °C for 5 h (Q×f = 51,382 GHz, εr = 9.74, and τf = −30.12 ppm/°C). Additionally, a thermal stable Y2.9Mg0.1Al4.9Si0.1O12-6 wt%TiO2 composite ceramic was developed. Based on this composite, a Wifi6E/7 patch antenna operating at 6.3 GHz and a millimeter-wave resonant antenna functioning at 27.1 GHz were designed and validated. This indicates the potential application prospects of garnet ceramics in 5G/6G radio communication technologies.

Quad-PortMIMO dielectric ResonatorAntenna with filtering response for IoT application

ABSTRACT This article presents a four-port Multi-Input Multi-Output (MIMO) antenna based on Dielectric Resonators (DR), showcasing excellent filtering characteristics, high isolation between ports, and strong diversity performance. The initial step introduces a single-port filtering Dielectric Resonator Antenna (DRA) utilizing the HEM11δ mode, featuring a complementary split ring resonator (SRR) feed structure that excites the cylindrical DR. This feed structure enables the independent adjustment of one resonance frequency and two radiation nulls. The experimental results confirm that the designed radiator works in between 2.35 and 2.57 GHz with an isolation level of more than 25 dB. The value of the gain is around 5.0 dBi within the operating band, while it is less than −15 dBi outside the working band. All these features make the designed MIMO radiator applicable for IoT applications.

Quasiparticle Poisoning of Superconducting Qubits from Resonant Absorption of Pair-Breaking Photons.

The ideal superconductor provides a pristine environment for the delicate states of a quantum computer: because there is an energy gap to excitations, there are no spurious modes with which the qubits can interact, causing irreversible decay of the quantum state. As a practical matter, however, there exists a high density of excitations out of the superconducting ground state even at ultralow temperature; these are known as quasiparticles. Observed quasiparticle densities are of order 1 μm^{-3}, tens of orders of magnitude greater than the equilibrium density expected from theory. Nonequilibrium quasiparticles extract energy from the qubit mode and can induce dephasing. Here we show that a dominant mechanism for quasiparticle poisoning is direct absorption of high-energy photons at the qubit junction. We use a Josephson junction-based photon source to controllably dose qubit circuits with millimeter-wave radiation, and we use an interferometric quantum gate sequence to reconstruct the charge parity of the qubit. We find that the structure of the qubit itself acts as a resonant antenna for millimeter-wave radiation, providing an efficient path for photons to generate quasiparticles. A deep understanding of this physics will pave the way to realization of next-generation superconducting qubits that are robust against quasiparticle poisoning.

A Wideband Circularly Polarized Dielectric Resonator Antenna with Filtering Response

A Wideband Circularly Polarized Dielectric Resonator Antenna with Filtering Response

Fabrication of compact circular ring antenna loaded with Gd-YIG ferrites: Photon–magnon interaction

In telecommunications technology, transmitting and receiving signals is not possible without an integrated antenna. Recently, novel approaches of transmitting and receiving signals using advancement in quantum technology as “information coherent transfer” have been emphasized which overcomes the limitations of superconducting qubits. In the present investigation, a compact-sized circular-ring antenna was designed for a 12 GHz centre frequency. The antenna was topped with Gd(x)-doped YIG (x = 0.0, 0.1, 0.2, 0.3) thin disks to investigate its tunable operation over the tri-band (C to Ku) frequencies due to the photon–magnon coupling, which enables coherent qubit information transmission from an electromagnetic (EM) carrier to the magnons. The proposed prototype of the antenna is validated using HFSS simulation. To characterize the frequency tunability of the designed antenna, we measured the return loss (S11) via a vector network analyzer as a function of dc magnetic field. Different concentrations of Gd-doped YIG ferrites (Gdx-YIG) have been loaded on ring antennas to observe strong anti-crossing phenomena with the application of an external magnetic field. The designed antenna has a tunability of around 300% for a small applied magnetic field up to 3.7 kOe. The maximum gain of dual resonance antenna is 1.4 for higher magnetic field of 3.7 kOe. The highest efficiency and lowest bandwidth of 30% and 14% respectively, for Gd0.1-YIG disk are observed. The measured normal mode splitting spectrum as a function of bias magnetic field that gives the maximum coupling strength is 153 MHz for a Gd concentration of 0.1. For practical applications, such antennas are suitable for use in tunable tri-band or multi-band applications (C to Ku).

Design of the Low-Profile, Bandwidth-Enhanced, Omnidirectional, and Polarization-Diversity Dielectric Resonator Antenna Employing a New Mode Combination

Design of the Low-Profile, Bandwidth-Enhanced, Omnidirectional, and Polarization-Diversity Dielectric Resonator Antenna Employing a New Mode Combination