Rectangular Dielectric Resonator Antenna Research Articles

Compact half H‐shaped dielectric resonator antenna for wideband applications

AbstractIn this study, the authors present the design of a half H‐shaped dielectric resonator antenna (DRA) for compact size and wide bandwidth. The trapezoidal patch feed is used to excite the DRA, which results in TE113Y and TE115Y resonant modes of the rectangular DRA (RDRA). It is found that the broad‐side higher‐order TE113Y with the TE115Ymode is used in the proposed design to make it wideband. The effective dielectric constant of the proposed DRA is reduced by the slots and then the structure is made half to make it compact. Finally, for further improvement in bandwidth, the size of the ground plane is reduced, which increases the parallel capacitive reactance and decreases the Q‐factor. The proposed structure achieves measured impedance bandwidth S11 ≤ −10 dB of 75% (4.30–9.50 GHz) with a maximum gain of 7.20 dB. The proposed DRA is applicable for WLAN (5.15–5.72 GHz) and orthogonal frequency‐division multiplexing 802.11a (5.72–5.85 GHz).

Dual-Band Circularly Polarized Hybrid Dielectric Resonator Antenna for 5G Millimeter-Wave Applications

This paper proposes a dual-band circularly polarized (CP) rectangular dielectric resonator antenna (DRA) for 5G millimeter wave wireless communications. The proposed DRA consists of a novel modified cross-flower exciting (MCF) slot and a rectangular ceramic dielectric resonator (DR). With the help of the compact MCF feeding slot, the fundamental modes TEδ11x/TE1δ1y and higher-order modes TEδ13x/TE1δ3y of the DR can be excited to achieve CP dual-band characteristics. In addition, the MCF slot works as a radiator at 26 GHz and 39 GHz to enhance the DRA bandwidth. More importantly, these two operational bandwidths can be controlled independently at the lower and upper bands. The proposed DRA is designed, fabricated and measured. The measured results show that the proposed dual-band CP DRA achieves 3 dB axial-ratio (AR) bandwidths of 19.8% and 7.8% with peak gains of 5.62 dBic and 6.74 dBic for the lower and upper bands.

Implementing the single/multiport tunable terahertz circularly polarized dielectric resonator antenna

A tunable terahertz circularly-polarized dielectric resonator antenna is implemented and numerically studied. An aperture coupled terahertz rectangular dielectric resonator antenna operating with the fundamental magnetic dipole is designed. The modal field distribution is perturbed using the material-perturbation technique and the electric field vectors are aligned in the horizontal plane with their orthogonal components having quadrature phase difference between them. Consequently, the circular polarization is obtained in the operating passband. The proposed antenna provides the 10-dB impedance bandwidth of 12.94% (4.27–4.86 THz) and 3 dB axial ratio bandwidth of 3.77% (4.43–4.60 THz). Moreover, tunability is achieved by modulation in the chemical potential of graphene layer coated at the top of the dielectric resonator by applying an electrostatic bias voltage. In addition, antenna provides the gain of 6.45 dBic along with 98% radiation efficiency. The proposed antenna can also be used for the implementation of multi-port wireless THz communication systems with the advantage of tunable CP response with impeccably high radiation performance parameters. A two-port multi input, multi output (MIMO) antenna is implemented with the usage of the proposed metal strip coated DR. This antenna provides high isolation between both the ports along with polarization response and pattern diversity with the acceptable value of MIMO performance parameters like envelop correlation coefficient and diversity gain.

A Novel Single-Fed Dual-Band Dual-Circularly Polarized Dielectric Resonator Antenna for 5G Sub-6GHz Applications

In this research article, a single-fed dual-band circular polarized (CP) dielectric resonator antenna (DRA) for dual-function communication, such as GPS and WLAN, was made. Initially, the proposed design process was initiated by designing a linearly polarized singly fed-DRA. To attain CP fields, the cross-shape conformal metal strip was optimized to excite the fundamental and the high-order mode in the two frequency bands. The metallic strip (parasitic) was utilized on top of the rectangular DRA to improve and widen the impedance and axial ratio (AR) bandwidth. This step led to a 2.73% improvement on the lower band and an impact of 6.5% on the upper band while on the other side a significant improvement was witnessed in the AR bandwidth in both frequency bands. A prototype was designed and fabricated in order to validate its operations. The measurement outcomes of the proposed antennas authenticated wideband impedance bandwidths of 6.4% and 25.26%, and 3-dB axial ratios (AR) of 21.26% and 27.82% respectively. The prototype is a decent candidate for a global positioning system (GPS) and wireless local area network (WLAN).

Circularly polarized rectangular dielectric resonator antenna with metallic strips load for WLAN application

AbstractThis article presents a circularly polarized rectangular dielectric resonator antenna (CP RDRA) loaded with metallic strips. The dielectric resonator (DR) with metallic strips on the top surface is excited by a slot aperture feed that excites two orthogonal modes to provide circular polarization. The proposed CP RDRA does not require any complex‐shaped dielectric resonator and simplifies the overall design. A prototype of the proposed antenna has been fabricated and validated. It has measured impedance bandwidth between 4.8 and 5.6 GHz and 3 dB axial ratio bandwidth between 5.1 and 5.43 GHz. The axial ratio beamwidth of more than 155° in the XZ and YZ planes is obtained.

A novel wide dual band circularly polarized dielectric resonator antenna for milli meter wave 5G applications

A novel singly fed Dielectric Resonator Antenna (DRA) is proposed here for milli meter wave 5G (Fifth Generation) frequency band applications. The DRA has achieved wide dual bandwidth with circular polarization at the defined 5G frequency bands. The resonances of this dual band antenna occur at 22.06 GHz, 24.5 GHz and 29.84 GHz. The percentage bandwidth |S11| < −10 dB of 26.3% is achieved at the first band (19.52–26.36 GHz) and 7.69% at the second band |S11| < −10 dB (28.26–30.26 GHz). Both the achieved bands here are covered under the Band 30 GHz category of 5G frequency spectrum. Compared to the conventional rectangular DRA, a novel trapezoidal shaped DRA is designed here which is fed by a microstrip line with characteristics impedance of 50 Ohm. The defined electrical dimensions of the DRA are 0.25λ0 × 0.29λ0 × 0.22λ0 considering 26 GHz as its resonating frequency. The DRA is placed over a Rogers substrate with dimensions 0.5λ0 × 0.5λ0 × 0.1λ0 and permittivity of 2.2. The DRA is circularly polarized and has a 3-dB axial ratio bandwidth of 5.23%. The DRA has achieved a gain value of 3.28 dB. Milli meter wave communications require wideband antennas with circular polarization features to support high throughput communication channels. This singly fed DRA has achieved wide dual bandwidth with circular polarization and is more suitable for indoor 5G small cell applications.

Y- shaped dielectric resonator MIMO antenna for omnidirection radiation pattern

ABSTRACT A three-port Y-shaped DRA multiple-input-multiple-output (MIMO) antenna is proposed for prospective 5 G applications. Three Rectangular DRA form a Y-shaped DRA placed on the circular ground (r = 50 mm). Each element of the DRA is fed by conformal microstrip line which generates TE11δ and TE12δ transverse modes. The symmetricity of the structure is maintained by locating three arms of DRA at a separation of 120°, which generates three-directional patterns at 0°, 120°, and 240° and offers good diversity. Antenna offers 3.7–7.19 GHz measured impedance bandwidth and isolation below −10 dB between all ports over the entire operating frequency band. 8 dBi peak gain is obtained at 5.75 GHz frequency.

Metasurface Lens-Integrated Rectangular Dielectric Resonator Antenna with Enhanced Gain

Metasurface Lens-Integrated Rectangular Dielectric Resonator Antenna with Enhanced Gain

Effect of Cylindrical Shaped Material Perturbation on Resonance of Dielectric Resonator Antenna

The paper presents a concept of cylindrical shaped material perturbation in rectangular dielectric resonator antenna (RDRA) which can be used for gain and bandwidth enhancement over original DRA. Material perturbation of cylindrical shape in two orthogonal directions will result in change of resonance of isotropic rectangular dielectric resonator antenna. The Effect of change of radius of cylinder for different dielectric materials is investigated. The proposed RDRA with centered cylindrical shape perturbation (PRDRA_CC) is analyzed theoretically using perturbation theory and simulated on 3D EM simulator HFSS. Theoretical and simulated results are compared and good agreement between two is obtained. Material perturbation provide wide tuning range, improved degree of freedom and hence more flexibility in designing antenna for given frequency range of application. Further, material perturbation and wall perturbation can be combined for obtaining polarization diversity in DRAs.

High-Gain Dual-Band Waveguide-Fed Dielectric Resonator Antenna

A distinctive configuration of rectangular waveguide-fed hemispherical dielectric resonator antenna (HDRA) for high-gain dual-band operation is described in this letter. A cylindrical-shaped hard rubber with a circular slot and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\epsilon_r = 3$</tex-math></inline-formula> is inserted between HDRA and ground plane to achieve dual-band, excellent coupling, enhanced bandwidth, and high gain. The structure of the antenna is very simple to fabricate. Measured results show that the proposed antenna radiates in two bands with resonant frequencies 7.65 and 10.04 GHz. The first band provides a bandwidth of 4.98% and a high gain of 11.72 dBi with a broadside radiation pattern. The second band enables wideband operation with an impedance bandwidth of 12.68% and a gain of 11.5 dBi. The structure attains high coupling efficiency in both bands.

Gain and Bandwidth Enhancement of X-band Compact Dielectric Resonator Antenna with Defected Ground Structure

This article presents an effective technique of gain and bandwidth enhancement for the dielectric resonator antennas (DRAs). The technique incorporates defected ground structures (DGSs) in the DRAs. Two DGS-based rectangular DRAs (DGS-RDRAs) with compact dimensions (39.6 mm × 29.2 mm) are proposed for the RADAR, satellite downlink, and other X-band communications. The DGS-RDRAs are designed by engraving circular and rectangular slots in their ground planes. Two prototypes of the proposed DGS-RDRAs are fabricated and measured so as to validate them. The measured results illustrate that the DGS-RDRA with a circular slot provides an impedance bandwidth (IBW) of 51.8% (8.413–14.29 GHz). The IBW for the rectangular-slotted DGS-RDRA is 18.69% (8–9.65 GHz). The antenna gains of 4.13 and 4.05 dBi are achieved by the circular-slotted and rectangular-slotted DGS-RDRAs, respectively. Other antenna parameters such as reflection coefficient and impedance of the antenna are also analysed. The resultant parameters obtained by the proposed DGS-RDRAs are compared with the similar type of existing DRAs in the literature. The comparisons further validate the proposed DGS-RDRAs as the best suitable candidate for the X-band applications.

Tunable terahertz dual-band circularly polarized dielectric resonator antenna

A tunable terahertz (THz) dual-band circularly polarized (CP) dielectric resonator (DR) antenna (DRA) is numerically analysed and implemented. Initially, an aperture coupled dual-band rectangular DRA is designed. This operates with the fundamental mode in the lower band and third order mode in the upper band and provides the linearly polarized response. The diagonal corners of the rectangular DR are truncated for obtaining the orthogonal degenerate components of the operating modes and thus the CP response is achieved. The tunability is achieved in the frequency response by applying a monolayer graphene material coating at the radiating surface of the chamfered DR. The antenna offers 10 dB impedance bandwidth of 18.41% (3.21−3.86 THz) and 4.7% (4.77−5.0 THz) along with 3 dB axial ratio bandwidth of 3.48% (3.38−3.5 THz) and 1.39% (4.98−5.05 THz). Furthermore, the proposed tunable dual-band THz CPDRA provides the gain of more than 6 dBic along with the radiation efficiency of more than 95% in each operating band.

Ultra-Wideband Annular Ring Fed Rectangular Dielectric Resonator Antenna for Millimeter Wave 5G Applications

In this article an ultra-wideband rectangular Dielectric Resonator Antenna is designed for millimeter wave 5G frequency band applications. Indoor 5G communications require antenna system with wide bandwidth and high efficiency to enhance the throughput in the channel. To fulfill such requirements a Dielectric Resonator Antenna (DRA) is designed here which has achieved an ultra-wide bandwidth of 20.15% (22.32–27.56 GHz) which is 5.24 GHz of bandwidth centered at 26 GHz as resonating frequency. This covers the complete band 30 (24.3–27.5 GHz) of 5G spectrum. 26 and 28 GHz are considered as most popular frequencies in millimeter wave 5G communications. The aperture fed DRA designed here has also achieved an efficiency of 96 percentage with maximum radiation in the broadside direction (Phi = 0, Theta = 0). The measured gain of the DRA is 6.3 dB. The DRA designed here has dimensions of 0.25 λ0×0.22 λ0×0.12 λ0. under the characteristic's mode. The DRA is placed over a substrate with dimensions 0.5 λ0×0.5 λ0×0.02 λ0. A cross slot aperture has been made on the ground plane which is placed above to the substrate. Here a full ground plane is used to resonate the antenna and is of similar dimension to the substrate. A microstrip line with two concentric rings makes an annular feed structure is used to excite the DRA and is placed below the substrate. The DRA is excited here in characteristics mode TE1Y1 and is the only mode of excitation. The DRA is linearly polarized, and the characteristic mode of excitation is maintained with 50 Ohm input impedance of the antenna. The DRA also gives here a good difference between the co-pol and cross pol approximately 15 to 20 dB. This antenna is more suitable for 5G indoor applications in millimeter wave frequency band centered at 26 GHz.

Aperture coupled modified rectangular dielectric resonator antenna arrays for X-band applications

This paper proposes an aperture coupled 3×3 rectilinear geometry-based periodic modified rectangular dielectric resonator antenna array for X-band applications. In this paper, the complex electromagnetic field problem of RDRA is addressed through a modified rectilinear-shaped DRA. Notches are created on the dielectric resonator to alter the normal components of the electric field pattern instantaneously. It leads to the reduction in the magnitude of reactive current density, resulting in a lessening of the Q-factor and enhancement of the bandwidth. This antenna shows multiband response, resonating at 8.42, 10.08, and 11.60 GHz frequency with a peak gain of 12.94 dBi at 9.75 GHz with consistent gain stability over the entire frequency band of operation. The radiation efficiency is around 96.1% due to low losses. The impedance bandwidths for different bands are 4.51%, 2.77%, and 4.56% at the resonating frequency of 8.42, 10.08, and 11.60 GHz. A comparative analysis of input and output characteristics is carried out between single, double, and nine-cell arrays. The designed antenna is excited by a branch line series-corporate constrained micro-strip feeding network with three apertures. This novel design is suitable for microwave X-band applications.

A Study on Application of Dielectric Resonator Antenna in Implantable Medical Devices

Worldwide, a large number of patients are benefited every year due to technological advancement in implantable medical devices (IMDs) such as in hyperthermia and bio-telemetry. The combination of sensors and antennas defined the quality of the implantable device. Antenna communities strive hard to fulfill the needs of the medical world by introducing new designs and concepts in this field. The purpose of this study is to identify major existing challenges and provide suitable solution of these challenges for implant applications. Present implant antennas have faced inferior performance due to high metallic losses and varied implant depth. The human body is a combination of dielectric materials, regardless of whether it is liquid (eg. water), gels or hard bones. In this study, first time a dielectric resonator antenna (DRA) resonating at 2.45 GHz, has been proposed as an implantable antenna with no metallic losses, varied implant depth performance and bio-compatibility. The implant DRA is placed on a bio-compatible polyvinyl chloride (PVC) substrate with a thickness of 0.5 mm. The rectangular DRA excited by a coplanar waveguide feed is proposed and its performance is compared with the help of four phantoms given in the literature. A detailed link design study was also undertaken in view of the different applications.

Modified microstrip fed of pentagon shape aperture coupling with RDRA for 5G wireless application

In this paper, a rectangular dielectric resonator antenna (RDRA) with modified microstrip feed is proposed. A pentagon-shaped aperture coupling with a bifurcated modified microstrip-line (MSTL) was used to excite the DRA element on the FR4 substrate's backside, resulting in a 3.8 GHz band. Optimizing the design parameters yields a 10% increase in impedance bandwidth, covering frequencies between 3.08 and 3.8 GHz. Maximum gain and radiation efficiency are shown to be 4.85 dB and 90%, respectively, in the operational band using the proposed DRA. As a result, the proposed antenna may be appropriate for use in 5G NR band systems.

Wide-Beam Dielectric Resonator Antennas Based on the Fusion of Higher-Order Modes

Geometry-induced resonant modes with intrinsic broad beam coverage are synthesized within step-shaped dielectric resonator antennas (DRAs). Following the idea of mode fusion, a synthesized mode inherits and combines the modal features from several conventional ones of regular DRAs. Superior flexibility and design freedom in beam shaping are thus obtained, leading to a 3 dB beamwidth exceeding 200° in both main planes. To form such a broad-beam mode, three regular higher-order modes from rectangular DRAs are chosen and merged. Their modal radiation patterns have fine complementation, meanwhile, they are readily excited by a shared feed. To further demonstrate the mechanism of mode fusion, the modal field distribution of the presented DRAs is analyzed. A design guide is presented as well.

A Novel Perforated Rectangular Dielectric Resonator Antenna with Semi Elliptical Conformal Feed for C-Band Applications

ABSTRACT In this article, a compact perforated rectangular dielectric resonator antenna (RDRA) for wideband applications is proposed. The basic RDRA is perforated to increase the bandwidth while lowering the quality factor. The resonator is fed by a semi-elliptical conformal microstrip line. A rectangular slot is etched at the center of the ground plane to optimize the radiation characteristics of the DR antenna. This topology offers 90.6% (4.08 –8.15 GHz) simulated bandwidth, and 97.2% (3.99 –8.23 GHz) measured bandwidth for dB with a gain of 3.5–7.8 dB tested over the operating bandwidth with more than 94% efficiency. mode at 4.5 GHz and mode at 6.4 GHz is excited by choosing optimized dimensions of the RDRA. The proposed antenna is best suitable for the entire C-band applications.

A Novel Single-Feed Filtering Dielectric Resonator Antenna Using Slotline Stepped-Impedance Resonator

A novel single-feed filtering dielectric resonator antenna (FDRA) with quasi-elliptic bandpass response is proposed in this brief. The proposed FDRA consists of a shunted slotline stepped-impedance resonator (SSIR), a rectangular dielectric resonator antenna (DRA) and a microstrip feedline with a pair of transverse arms. The antenna is excited in the fundamental TE <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{11\delta }$ </tex-math></inline-formula> mode, the transverse arm mode and the two SSIR modes. Moreover, three radiation nulls are produced near the edges of the passband by the SSIR and the transverse arm of microstip feedline, respectively. A prototype FDRA is fabricated and measured, which offers a bandwidth ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$| S_{11} | &lt; -10$ </tex-math></inline-formula> dB) of 21.14% (3.13 - 3.87 GHz), and a peak realized gain of 5.3 dBi within passband. The realized gain shows a decline of 20 dB at passband-edge, which exhibits high selectivity.

A novel wideband fractal rectangular dielectric resonator antenna with improved radiation performance

A wideband fractal rectangular dielectric resonator antenna (RDRA) based on the hook-shaped dipole is proposed for wireless communication, which exhibits stable, symmetric radiation patterns and low cross-polarization. The antenna consists of a Koch-like fractal rectangular dielectric resonator antenna (FRDRA) and a hook-shaped electric dipole (HSE-Dipole), which are equivalent to the magnetoelectric (ME) dipoles. The symmetrical radiation pattern with gain enhancement and suppression of backward lobe is achieved by the complementary combination of the electric and magnetic dipoles. The Koch-like fractal structure is used to improve the impedance matching of the RDRA with 15% size reduction. The antenna is excited by the substrate integrated waveguide (SIW) feeding network, which takes the advantage of compact size and low insertion loss. Due to the air gap between the FRDRA and HSE-Dipole, the fundamental TE1δ1 and high-order TE1δ2 modes of the RDRA are both generated to obtain the 19.5% impedance bandwidth. The prototype is fabricated and measured to validate the antenna design, which shows remarkable radiation performance including the front to back ratio (FTBR) of >20 dB, the average gain of 5.96 dBi and low cross-polarization.