Rectangular Dielectric Resonator Antenna Research Articles

Bandwidth enhancement by using parasitic patch on dielectric resonator antenna for sub-6 GHz 5G NR bands application

In this Research article, a circularly polarized Dielectric Resonator Antenna (DRA) that operates in the sub-6 GHz spectrum for future 5G New Radio (5G NR) applications has been proposed. The novel design consists of a Roman Three shaped conformal metal strip excited through a singly fed mechanism. The proposed technique is responsible for circular polarization by exciting the higher-order degenerate modes, i.e., TExδ13 and TEy1δ3.Initially, the roman three shape design produces a narrow 10-dB impedance bandwidth of 10.68% (3.23–3.59 GHz) and axial ratio bandwidth of just 1.47% (3.35–3.41 GHz); to cover the whole 5G NR Bands (n77/n78), the parasitic patch has been introducing at an optimum location on rectangular DRA, such arrangement not only improves impedance matching |S11 | ≤ −10 dB bandwidth by 180 %, i.e., 27.73% (3.26 – 4.35 GHz) but also cover the desired band. Along with this, a noteworthy improvement of ∼ 250% in 3-dB overlapping axial ratio (AR) bandwidth has been attained. In parallel to the Sub-6 GHz 5G NR Bands applications, this antenna can be used for vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) applications. Finally, the fabricated antenna prototype is tested and offers decent performance in desired parameters. The measured results agree reasonably with simulation results.

Analysis of an Inhomogeneous Circularly Polarized Hollow Dielectric Resonator Antenna Using Perturbation Theory

The perturbation approach is presented here for the first time for the analysis of an inhomogeneous circularly polarized rectangular dielectric resonator (DR) antenna (DRA). The inhomogeneous permittivity is created by perturbing a rectangle-shaped region of different material inside the rectangular dielectric resonator antenna (RDRA). The orthogonal degenerate modes with a phase difference of TE111x, and TE111y, are excited simultaneously for achieving circular polarization. A simple expression for the calculation of the resonant frequency and optimal axial ratio point for a circularly polarized (CP) inhomogeneous RDRA is presented here. Theoretical results obtained from the proposed theory are compared with theoretical, simulated, and experimental data available in the literature. The proposed analysis results show optimal axial ratio point calculations within a 1% range of the simulated and experimental data, which is better than the previous transverse transmission line reported method, having an error of approximately 4%. The advantages, accuracy, and simplicity of perturbation theory for DR are discussed in detail. The proposed theory can be easily extended for higher order modes and other shapes of material perturbation and anisotropic DRAs. The proposed technique will help in incorporation of the perturbation in the DR so that CP radiation can be obtained in an easy way.

Circularly polarized rectangular dielectric resonator antenna with elliptical aperture feed for 5 GHz ISM band

In this article, a new elliptical slot aperture feed circularly polarized (CP) rectangular dielectric resonator antenna (RDRA) has been proposed. The nonresonant slot excites two spatially orthogonal resonant frequencies in RDRA to produce CP waves. TEx111 and TEy111 are the orthogonal modes produced by the 450 inclined elliptical slot with respect to microstrip feed. Also, the sense of polarization at the resonance frequencies can be controlled by changing the orientation of the slot. The antenna performances in terms of impedance bandwidth, 3-dB axial ratio, and gain are validated experimentally. The proposed antenna can be used in 5 GHz ISM band for WiFi/satellite communications.

Design of a broadband blade and DRA hybrid antenna with hemi-spherical coverage for wireless communications of UAV swarms

Blade antennas are widely used for airborne communications owing to their light weight and wide bandwidth. However, radiation pattern of a blade antenna is monopole-like and yields a deep null towards its top direction. This will cause serious blind spots for the aircraft towards its top and bottom directions, which is not desirable for future avionic networks. To solve this issue, a dielectric resonator antenna (DRA) is added to the blade antenna and forms a new design. A rectangular DRA is adopted in this paper to illustrate the main idea. The rectangular DRA operates in the lowest TE111 mode and its radiation pattern covers the high elevation angle region. The blade antenna, on the other hand, has a nearly omni-directional radiation pattern in the low elevation angle region. Combination of the DRA and blade antenna can provide a hemispherical coverage with relatively small ripples. A closed-form model is presented to explain the radiation mechanism of the hybrid antenna. For verification, a prototype antenna is designed, fabricated and measured. Its impedance bandwidth covers 1.3–2.4 GHz and its radiation patterns yield small ripples in the top hemi-sphere until 2.1 GHz.

Wideband Hybrid Dielectric Resonator Antenna for PCS/UMTS/WCDMA/WLAN/Wireless Broadband

The rectangular dielectric resonator antenna (RDRA) excited using a novel feeding structure to achieve wideband characteristics has been proposed in this article. The hybrid antenna concept has been utilized to excite the higher-order modes in RDRA and these modes are chosen close enough to enhance the bandwidth of the proposed antenna. The proposed hybrid DRA operates over the frequency band from 1.79 GHz – 3.18 GHz. The presented design finds its application for WLAN (2.4 GHz), WiMAX (2.5 GHz), PCS (1.85 GHz - 1.99 GHz), UMTS (1.92 GHz -2.17 GHz), WCDMA (2.1 GHz), and wireless broadband (2.3 GHz – 3.18 GHz).

Dual‐band modified rectangular shaped dielectric resonator antenna with diversified polarization feature

AbstractIn this communication, the aperture coupled modified rectangular dielectric resonator antenna (rDRA) is designed and studied. The modified rectangular DRA is the same as Swastik shape. An asymmetrical microstrip line‐fed aperture stimulated a triple radiating mode pattern inside the ceramic material, that is, , respectively. Swastik‐shaped ceramic radiator provides two important advantages: (a) lower Q‐factor, which in turn improves the impedance bandwidth, and (b) the creation of degenerated orthogonal mode with 90° phase shifts, which provides CP waves in one of the operating bands. Experimental outcomes confirm that the proposed antenna is working in dual‐frequency bands, that is, 6.41–7.38 GHz and 10.2–12.8 GHz, respectively. It supports left‐handed CP waves from 11.51 to 11.89 GHz. The proposed antenna is widely employable for fixed service satellite (FSS) for defense applications.

Terahertz rectangular DRA for high speed communication applications

In this paper, design and implantations of terahertz rectangular DRA using HFSS simulator have been presented. The aspect ratio has played deterministic role for desired resonant modes excitation at terahertz frequencies. The antenna operates at 10 THz, hence can be used for high speed communications and terahertz sensors. Design is simple due to rectangular geometry, efficient due to use of DR, and unique using silicon as radiator. Mathematical modeling of 10 THz frequency using Terahertz DRA is also presented along with simulations results of S11 below -10dB , Gain of 4.89 dBi with good radiation pattern have been validated. These DRAs falls within visible frequency hence they can be used as artificial retinal photoreceptors. DR material has advantages over metallic antennas as they can operate with stability from microwave to optical regime. These optical antennas can be suitable for wireless transmission of TBPS data rate. Terahertz technology has effectively miniaturized the size of DRA. High speed communication at THz frequency can result into wide bandwidth and shall be able to provide Tbps data rate. Coherent states and control at optical frequencies have been formulated mathematically with unique characteristics at terahertz frequency.

Design and analysis of a compact circularly polarized DRA for off-body communications

A compact single fed circularly polarized dielectric resonator antenna (CPDRA) for off-body communication in wireless body area network (WBAN) applications is proposed. The proposed antenna consists of a modified rectangular DRA made of Al2O3 with a permittivity of εr = 9.8 and fed by a 50-Ω coaxial probe. Two unequal vertical slits are etched off from both the corner edges of the rectangular dielectric resonator to generate TEδ11x and TE1δ1y modes, and to reduce the overall size of the proposed antenna. Moreover, an efficient single layer equivalent phantom model is designed to reduce the simulation time for the analysis of off-WBAN communications. The proposed antenna is fabricated and characterized in free space as well as in on-body environment. It provides measured impedance and axial ratio (AR) bandwidths of 66.19% (4.72–9.39 GHz) and 15.01% (6.22–7.23 GHz) respectively in free space, 65.91% (4.73–9.38 GHz) and 16.02% (6.20–7.28 GHz) respectively in on-body environment. A full ground plane is used to provide unidirectional radiation pattern and greater isolation from the human body with low SAR i.e. 0.397 W/kg and 0.193 W/kg for 1 g and 10 g tissue respectively. These features make the proposed CPDRA is suitable for off-body communication and can easily be integrated in wireless devices.

Design of Rectangular Dielectric Resonator Antenna for Mobile Wireless Application

In this article, a pentaband rectangular DRA is explored and presented. The proposed antenna has a crescent-shaped radiating element with defected ground structure and it is feed by 50‐Ω microstrip line. The RDRA invariably has two similar dielectric resonators made up of RT5870 is positioned on top of the crescent-shaped patch. With the use of a dielectric resonator, the proposed structure has good improvement in impedance bandwidth and gain. The proposed rectangular DRA has penta operating frequency bands with resonant frequency at 1.49 GHz, 2.00 GHz, 2.50 GHz, 5.49 GHz, and 7.75 GHz. The projected structure exhibits the broadside radiation pattern with the maximum gain and directivity of 4 dBi and 4.5 dBi, respectively. The gig of the projected RDRA is validated with the help of simulated results by CST software. The observed results of the proposed antenna indicate that it can be a potential candidate for GPS, PCS, UMTS, ISM, WLAN, Wi-MAX applications.

An ultra-wideband rectangular ring dielectric resonator antenna integrated with hybrid shaped patch for wireless applications

Abstract A new wideband omni-directional compact rectangular ring dielectric resonator antenna (RRDRA) fused with slotted bevel shaped patch antenna is presented for the ultra-wideband (UWB) applications. The RRDR (rectangular ring dielectric resonator) is employed to generate lower order radiating modes with merge with the modes of patch to obtain high impedance bandwidth in UWB region. Further, RRDR use led to reduction in overall conductor loss to achieve high radiation efficiency. The proposed RRDRA structure achieved an impedance bandwidth covering the frequency range from 2.6–15.6 GHz, or ∼142%. The measured results show that the proposed DRA provides peak measured gain of 6.2 dBi and radiation efficiency of 90% at resonant frequency 6.3 GHz with stable omni-directional monopole like radiation patterns with low cross-polarization. The proposed antenna has a short ground plane of size 40 × 40 × 11.6 mm3 or ∼0.34λ 0 × 0.34λ 0 × 0.10λ 0 at 2.6 GHz.

Circularly Polarized DR-Rectenna for 5G and Wi-Fi Bands RF Energy Harvesting in Smart City Applications

A smart city necessitates spectrum and energy efficiency with increasing applications which demand an increasing number of nodes in the Internet of Things (IoT) system networks. In recent years, radio frequency (RF) energy harvesting is best suited to enhance the energy efficiency required for self-sustained IoT networks incorporated in smart cities. This work proposes a rectangular dielectric resonator antenna (RDRA), that comprises a rectangular dielectric resonator (DR) and slots loaded ground plane. The proposed antenna operates efficiently at 3.5 and 5.8 GHz frequencies and also achieves circularly polarized characteristics at two operating bands. A microstrip feeding approach opts for excitation of the proposed antenna. The radiational properties of the proposed antenna show that the antenna is suitable to operate for radio frequency energy harvesting in smart city applications efficiently. An HSMS2860 Schottky diode has been chosen for the rectification at two bands of frequencies. A proper impedance matching is achieved using microstrip transmission lines and rectangular stubs connected to the rectifier circuit. The proposed rectifier circuit offers the maximum power conversion efficiency (PCE) of 54.53% and 41.26% at 3.5 and 5.8 GHz frequencies respectively for 5 dBm input power. The output voltages obtained at two frequencies are 1.31 V and 1.16 V, respectively.

A Novel Wideband RDRA for WBAN Applications

A Wideband Rectangular Dielectric Resonator Antenna (RDRA) is presented in this manuscript. The proposed RDRA is designed for wideband body area network (WBAN) applications due to its compact size and wideband characteristics. The proposed antenna can be effectively integrated with modern medical devices for transmitting biological signals. WBAN attract variety of applications in monitoring human health in the domains such as sports, entertainment, defense, and healthcare industry. This manuscript presents a novel RDRA to meet recent research challenges as well as applications for future generation wideband RF-device technology for BANs. The miniaturized RDRA Antenna is designed for biotelemetry using HFSS 13, FEM based 3D EM Simulation Software

Higher-Order-Mode Triple Band Circularly Polarized Rectangular Dielectric Resonator Antenna

The paper presents a triband circular polarized rectangular dielectric resonator antenna. A single coaxial cable feeds the DRA to a double stub strip on the DRA side. A patch strip coupled to the feed assists in widening the bandwidth of the proposed DRA. The degenerate mode pair TE∂11x and higher-TE∂23x has been excited to achieve CP and enhance the antenna gain. The higher-order mode has been excited using a low-cost simple excitation mechanism without compromising on the size and shape of the DRA. An impedance bandwidth of 48% with a gain ~6–9 dBic was achieved in all resonance frequencies. Additionally, the AR bandwidth of 5.5%, 4.2%, and 2.76% was obtained at three different frequencies. Note that the proposed DRA exhibits a wide beamwidth of 112o, which is good for better signal reception. A comparison between the measured with simulated results shows that the measured results are matched by the simulated result trends.

Circular Patch Fed Rectangular Dielectric Resonator Antenna with High Gain and High Efficiency for Millimeter Wave 5G Small Cell Applications.

A novel method of feeding a dielectric resonator using a metallic circular patch antenna at millimeter wave frequency band is proposed here. A ceramic material based rectangular dielectric resonator antenna with permittivity 10 is placed over a rogers RT-Duroid based substrate with permittivity 2.2 and fed by a metallic circular patch via a cross slot aperture on the ground plane. The evolution study and analysis has been done using a rectangular slot and a cross slot aperture. The cross-slot aperture has enhanced the gain of the single element non-metallic dielectric resonator antenna from 6.38 dB from 8.04 dB. The Dielectric Resonator antenna (DRA) which is designed here has achieved gain of 8.04 dB with bandwidth 1.12 GHz (24.82–25.94 GHz) and radiation efficiency of 96% centered at 26 GHz as resonating frequency. The cross-slot which is done on the ground plane enhances the coupling to the Dielectric Resonator Antenna and achieves maximum power radiation along the broadside direction. The slot dimensions are further optimized to achieve the desired impedance match and is also compared with that of a single rectangular slot. The designed antenna can be used for the higher frequency bands of 5G from 24.25 GHz to 27.5 GHz. The mode excited here is characteristics mode of TE1Y1. The antenna designed here can be used for indoor small cell applications at millimeter wave frequency band of 5G. High gain and high efficiency make the DRA designed here more suitable for 5G indoor small cells. The results of return loss, input impedance match, gain, radiation pattern, and efficiency are shown in this paper.

Investigation and Development of 3D Printed Conventional Shape Compact UWB-DRAs for Societal Applications

The potential of polylactic acid (PLA) material as an ultra-wide band (UWB)-dielectric resonator antenna (DRA) created by 3D-printing technique are described in this scientific paper. PLA is an exceptional sort of biodegradable thermoplastic composite material having the dissipation factor (tanδ) of 0.05 and dielectric constant (e $${}_{\mathbf{r}}$$ ) of 3.47. Easily available as well as low-cost PLA based Dielectric Resonator Antennas (DRAs) of conventional geometries i.e., Rectangular DRA (RDRA), Cylindrical DRA (CDRA) and Triangular DRA (TDRA) have been explored and developed for broadband societal applications. These three definite constructions of the 3D assembly are utilized to demonstrate the attributes of the PLA as a DRA. Proposed structures of DRAs attain the wide bandwidth of 81.98%, 83.42% and 71.23% for RDRA, CDRA and TDRA respectively for |S11|< −10 dB. The average value of accomplished peak gain is ~ 4 dB for rated maximum frequency band. Therefore, proposed DRAs have an assortment of social utilization in C-, X- and Ku band, for example, climate checking, airport regulation and electromagnetic sensor.

A DRA With Engraved Groove and Comb-Like Metal Wall for Beamwidth Enhancement in Both E- and H-Planes

In this letter, a dielectric resonator antenna (DRA) with an engraved groove and a comb-like metal wall for beamwidth enhancement in both E- and H-planes is proposed. First, with an engraved groove, the radiation intensity on the top wall of the rectangular DRA can be enhanced, which significantly broadens the half-power beamwidth (HPBW) in the E-plane. Second, by placing a regular notched metal wall around the grooved DRA, HPBWs in both E- and H-planes can be greatly widened simultaneously. Finally, for the further improvement of HPBW in the H-plane, the regular notched wall is replaced by a 3-D printed comb-like metal wall. Vertical currents can be induced on the comb-like wall due to the coupling of the DRA, which can increase gain at low elevation angles and further enhance HPBW of 20°. Thus, HPBWs of the proposed antenna in both cutting planes can be improved step by step without scarifying each other and bandwidth. To verify the proposed design, an antenna prototype is fabricated and measured, which shows an impedance bandwidth of 38.2% (2.58–3.8 GHz), with excellent HPBW performance of 248° and 148° in the E- and H-planes, respectively.

Dual band dielectric resonator antenna for high-speed applications

The antennas for wireless communication devices have undergone a tremendous expansion from the external monoband resonant antenna to the internal non-resonant multi-band antenna. In this paper, a dual-band dielectric resonator antenna for high-speed applications is proposed. Due to the complex edge-shaped boundary between the dielectric and air in a rectangular dielectric resonator antenna, a complex closed form of expression is difficult to achieve. To address this problem a half-cut cylinder is placed over the rectangular dielectric to achieve excellent radiation characteristics. This proposed antenna provides a wide dual-band response with fractional impedance bandwidth of 21.92% and 19.09%while operating from7.32 GHz to 9.12 GHz and 10.71 GHz to 12.95 GHz. It provides an average gain of 3dBi with high gain stability in the entire operating frequency band. The radiation efficiency is found to be 96% due to low ohmic and dielectric losses. The cross-polarization is around 20 dB lesser than the co-polarization. Its gain and directivity can further be enhanced by implementing serial and parallel array structures. This design uses HFSS 14.0 commercial electromagnetic simulation tools.

Wideband and High Efficiency 64-Element RDRA Array for Radar Applications

This paper presents the capabilities of an $8\mathrm {\times }8$ Rectangular Dielectric Resonator Antenna (RDRA) planar array with broad bandwidth and high gain. To improve shielding of a multi-stage feeding network, the proposed array is designed using a stripline feeding network with two different substrates. To enhance impedance matching while keeping a sufficient F/B ratio of 20 dB, the lower ground of the stripline has a smaller dimension than the upper ground plane. The proposed array covers the frequency band from 3.79 to 6.29 GHz with 50% fractional bandwidth. The peak realized gain ranges from 18 to 22 dBi, with 85% of radiation efficiency throughout the frequency of interest. The overall size and weight of the array is $215\mathrm {\times } 215 \mathrm {\times }14.5$ mm3 and 650 g, respectively. Furthermore, the radiation patterns appear as low as 15 dB of peak-to-side lobe level with 25 dB cross polarization level, which makes the proposed array suitable for UAS (Unmanned Aerial System) radar applications. The measurements and simulations agree considerably.

A Low-Profile Dielectric Resonator Antenna With Compact-Size and Wide Bandwidth by Using Metasurface

A dielectric resonator antenna (DRA) with the loading of metasurface (MS) is proposed for low-profile, wide-bandwidth and compact-size. Firstly, an MS structure consisting of $6\times6$ periodic metallic patch cells is loaded above the DRA. It aims to excite an additional TM surface wave above the fundamental TE111 mode of the rectangular DRA. Then, the shorting walls are printed on two sides of the dielectric, thus moving down the operating frequency with respect to its TM surface wave mode. As such, the bandwidth of the antenna is significantly widened with compact-size under the operation of TE111 and TM surface wave modes. Finally, the proposed DRA with enhanced performance is fabricated and tested. The results show that an impedance bandwidth of the antenna is dramatically increased to about 17.2%, covering the frequency range from 1.75 to 2.08 GHz, which is about 9.6 times wider than the traditional DRA at the same thickness (1.8%). Besides, it still maintains the broadside radiation pattern with stable gain of around 6.6 dBi and fairly low cross polarizations of below −26 dB. Particularly, the overall size of the radiator still maintains as small as about $0.32\lambda _{0} \times 0.32\lambda _{0} \times 0.044\lambda _{0}$ . It should be noted that the analysis of the antenna is carried out by using Ansys HFSS software version 14.0 and ADS 2011.

A Wireless Power Transmitter With Uniform Power Transfer Coverage

To avoid the performance deterioration caused by the changing placement angle of a receiving antenna, a wireless power transmitter with uniform power transfer coverage is preferred. The utilization of a transmitting antenna with flat-top radiation patterns is the most effective approach. However, the existing antennas with flat-top radiation patterns usually are complex structures and bulky sizes. To mitigate these problems, a rectangular dielectric resonator antenna (DRA) is proposed to obtain flat-top radiation patterns for the first time. Flat-top patterns are realized in both the E and H planes by combining the TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">119</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sup> and TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">133</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">y</sup> modes of a rectangular DRA. For validation, both linearly polarized (LP) and circularly polarized (CP) flat-topped DRAs operating at 5.2 GHz were designed, fabricated, and tested. Reasonable agreement between the measured and simulated results is observed. For the LP design, stable flat-top patterns can be maintained from 5.18 GHz to 5.24 GHz. Across the operating frequency band, the measured 3-dB beamwidths are 86° and 58° in the E and H planes, respectively, with the side lobe levels lower than -13.9 dB. For the CP design, similar flat-top radiation patterns can be found. To demonstrate the effectiveness of the proposed transmitting antenna, the LP design is used to construct a wireless power transmitter, which can provide more power and also uniform power coverage within the desired angular sector.