Circularly Polarized Dielectric Resonator Antenna Research Articles

A Wideband Circularly Polarized Dielectric Resonator Antenna with Filtering Response

A Wideband Circularly Polarized Dielectric Resonator Antenna with Filtering Response

Wideband Circularly Polarized Dielectric Resonator Antenna with Wide Overlapped Axial-Ratio and Half-Power Beamwidths

Wideband Circularly Polarized Dielectric Resonator Antenna with Wide Overlapped Axial-Ratio and Half-Power Beamwidths

Fractal Cross-Slot-Coupled Antenna with Dielectric Resonator Elements having Circular Polarization

This article presents the design and analysis of an “ultra-wideband (UWB)” Fractal Cross-slot-Coupled Antenna with “Dielectric Resonator Elements (DREs)” exhibiting circular polarization and band-notched characteristics. The proposed antenna aims to reject the frequency range of 5.1 GHz to 5.9 GHz while maintaining high impedance bandwidth and radiation efficiency. A coplanar waveguide feeds the planar UWB antenna, featuring a narrow slot on the radiating element and a dielectric resonator mounted on top. Simulation results demonstrate excellent performance in terms of impedance bandwidth and radiation efficiency. To further improve the design for wireless applications, Fractal-slot-aperture coupled DRE antennas are employed. The proposed configuration takes into account the radiative efficiency and concomitant excitation of the rectangular DRE by a “Circularly Polarized Dielectric Resonator Antenna (CPDRA)” coupled through a fractal cross-slot. By appropriately adjusting the fractal cross-slot size, a wider “axial ratio (AR)” bandwidth is achieved through the combination of its resonance with the dielectric resonator. The antenna is designed utilizing the proposed fractal cross-slot-coupled CPDRA, with its architecture and efficiencies thoroughly investigated. The performance of the proposed antenna demonstrates its potential for various wireless communication applications, highlighting the advantages of integrating Fractal Cross-slot-coupled DREs in antenna design.

Circularly Polarized Multiple-Input Multiple-Output Dielectric Resonator Antenna for 5G Millimeter-Wave Application

A circularly polarized (CP) multiple-input multiple-output (MIMO) dielectric resonator antenna (DRA) is presented in this paper for 5G millimeter-wave (mm-wave) applications. This MIMO antenna consists of two high-order mode CP DRAs, which use the modified cross slots to generate the CP fields. Two complementary split ring resonators (CSRR) are used to isolate the surface current on the metal ground, which can increase the antenna isolation and optimize the axial ratio when each port is excited. The proposed MIMO antenna obtains a simulated impedance bandwidth from 25.41 to 31.18 GHz and an axial ratio (AR) bandwidth (AR < 3 dB) from 25.49 to 29.52 GHz for the 5th generation wireless communication applications. The measured results show that the antenna covers the overlapped bandwidth of 11% and isolation less than −25 dB over the frequency band range. The measured average (peak) gain is 5.84 (6.24) dBic at 26.5 GHz to 29.5 GHz for port 1 and 6.90 (7.27) dBic for port 2.

Design and optimization of circularly polarized dielectric resonator antenna array based on Al2O3 ceramic

A comprehensive design of an ultra-broadband circularly polarized (CP) dielectric resonator antenna (DRA) array operating in the C-band for fifth-generation (5G) communication systems is presented in this paper. The objective is to achieve a compact antenna size capable of receiving and transmitting CP electromagnetic waves over a wider bandwidth. The material chosen for the dielectric resonator (DR) is Alumina (Al2O3) ceramic, known for its low dielectric loss and exceptional mechanical properties, making it an ideal candidate for the DR. The proposed design utilizes a 2 × 2 array of cross-shaped DRs, fed by a compact circular phase-shift feeding network with double-point feeding. This configuration results in a 3-dB axial ratio (AR) bandwidth of 48.7 % and an impedance matching bandwidth (IMB) of 53.2 %. The antenna's horizontal size is reduced to 1.17 × 1.17λ02, and the gain is significantly enhanced by exciting multiple Mie resonances in the stacked DRs, yielding a measured peak gain of 12.48 dBic. These outstanding features position the CP DRA array as an excellent choice for 5G communication systems.

Triple-Band Circularly Polarized Dielectric Resonator Antenna (DRA) for Wireless Applications

This paper proposes a new dielectric resonator antenna (DRA) design that can generate circularly polarized (CP) triple-band signals. A triple-band CP DRA antenna fed by a probe feed system is achieved with metal strips structure on side of DRA structure. The design start with conventional rectangular DRA with F shaped metal strips on DRA structure alongside the feed. Then, the F metal strip is enhanced by extending the length of the metal strip to obtain wider impedance bandwidth. Further improvement on the antenna performance is observed by improvised the conventional DRA structure. The method of removing part of DRA bottom resulted to higher antenna gain with triple band CP. The primary features of the proposed DRA include wide impedance matching bandwidth (BW) and broadband circular polarization (CP). The primary features of the proposed DRA include wide impedance matching bandwidth (BW) and broadband circular polarization (CP). The CP BW values recorded by the proposed antenna were ∼ 11.27% (3.3–3.65 GHz), 12.18% (4.17–4.69 GHz), and 1.74% (6.44–6.55 GHz) for impedance-matching BW values of 35.4% (3.3–4.69 GHz), 1.74% (5.36–5.44 GHz), and 1.85% (6.41–6.55 GHz) with peak gains of 6.8 dBic, 7.6 dBic, and 8.5 dBic, respectively, in the lower, central, and upper bands. The prototype of the proposed antenna geometry was fabricated and measured. A good agreement was noted between the simulated and the measured results.

A Review of Circularly Polarized Dielectric Resonator Antennas: Recent Developments and Applications.

A comprehensive review on recent developments and applications of circularly polarized (CP) dielectric resonator antennas (DRAs) is proposed in this paper. DRAs have received more considerations in various applications due to their advantages such as wide bandwidth, high gain, high efficiency, low losses, and low profile. A broad justification for circular polarization and DRAs is stated at the beginning of the review. Various techniques such as single feed, dual, or multiple feeds used by different researchers for generating circular polarization in DRAs are briefly studied in this paper. Multiple-input-multiple-output (MIMO) CP DRAs, which can increase channel capacity, link reliability, and data rate, have also been analyzed. Additionally, innovative design solutions for broadening the circular polarization bandwidth and reducing mutual coupling are studied. Several applications of DRA are also discussed comprehensively. This paper finishes with concluding remarks.

Stable High-Gain Linearly and Circularly Polarized Dielectric Resonator Antennas Based on Multiple High-Order Modes

Dielectric resonator antennas (DRAs) under high-order multiple-modes resonator (MMR) for stable high gain are proposed in this communication. The approach is to implement slot cuts on the surface of DR for reconstructing the electric field distribution of high-order resonance modes. In this way, the sidelobes are reduced and two high-order modes are reallocated to construct a continuous wide band. Various MMR configurations were proposed in this work. First, a DRA operating in TE <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathrm {x}}_{031}$ </tex-math></inline-formula> and TE <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathrm {x}}_{051}$ </tex-math></inline-formula> modes is proposed with a pair of loaded slots to realize a fractional bandwidth (FBW) of 26% and a stable gain as high as 8.3 dBi within the desired passband. Second, a DRA with TE <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathrm {x}}_{051}$ </tex-math></inline-formula> and TE <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathrm {x}}_{071}$ </tex-math></inline-formula> modes is developed by introducing two pairs of slots, and an impedance FBW of 12.8% and a stable gain as high as 11 dBi are achieved. Third, three pairs of slots are introduced to the DRA with TE <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathrm {x}}_{091}$ </tex-math></inline-formula> and TE <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\mathrm {x}}_{0,11,1}$ </tex-math></inline-formula> modes, and an impedance FBW of 6.4% and a stable antenna gain as high as 12.3 dBi are obtained. At last, a circularly polarized (CP) DRA array with four proposed linearly polarized (LP) DRA elements is designed with an impedance bandwidth of 51.8%, a 3 dB axial-ratio (AR) FBW of 32%, a peak gain of 13.89 dBic, and a 1 dB gain bandwidth of 19.9%.

A Circularly Polarized Dielectric Resonator Antenna Based on Quasi-Self-Complementary Metasurface

In this communication, a circularly polarized (CP) dielectric resonator antenna (DRA) based on quasi-self-complementary metasurface (MS) has been proposed. Due to the quasi-self-complementary characteristic of the proposed MS, the phase difference of the transmission coefficients between two orthogonal linear polarizations is 90° in the frequency band from 25.5 to 26.5 GHz. The DRA with the proposed MS can realize the transformation from linear polarization to circular polarization at 25.6–25.99 GHz. The proposed MS significantly increases the gain and CP bandwidth of the DRA. The working bandwidth of the proposed antenna is included in the New Radio FR2 frequency band totally, which is considered as the follow-up expansion frequency of fifth-generation (5G) communication. The proposed MS-based antenna has realized the linear-to-circular polarization transformation in millimeter frequency band without additional substrate, which has not been researched yet.

3-D-Printed Wideband Circularly Polarized Dielectric Resonator Antenna With Two Printing Materials

A new 3-D-printed wideband circularly polarized (CP) dielectric resonator antenna (DRA) with two printing materials is investigated. The DRA has a multilayer comb-shaped structure at its top for generating CP fields. Three dielectric strips are embedded inside the DRA body to support multiple transverse-electric (TE) DRA modes to widen the DRA bandwidth. To slightly improve the axial-ratio (AR) performance, the DRA is twisted in the horizontal plane. For demonstration, a prototype operating in C-band was designed and printed with two different materials. The reflection coefficient, AR, radiation pattern, antenna gain, and efficiency of the antenna are measured, and reasonable agreement between the measured and simulated results is observed. The prototype has a measured 10 dB impedance bandwidth of 69.7% (4.80–9.94 GHz) and 3 dB AR bandwidth of 68.6% (4.52–9.24 GHz), achieving a wide overlapping bandwidth of 63.2% (4.80–9.24 GHz). Both the AR and overlapping bandwidths are record-high for a single-fed CP DRA. The prototype has a measured peak antenna gain of 8.3 dBic inside the overlapped passband.

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.

Tunable Terahertz Circularly Polarized Dielectric Resonator Antenna with the Higher Order Modes

Tunable Terahertz Circularly Polarized Dielectric Resonator Antenna with the Higher Order Modes

A Compact Sequentially Rotated Circularly Polarized Dielectric Resonator Antenna Array

In this study, a compact 2 × 2 circularly polarized (CP) sequentially rotated (SR) dielectric resonator antenna (DRA) array operating in the IEEE 802.11a band is presented. To acquire the CP radiation, an elliptical slot (ES) was introduced to couple a rectangular dielectric resonator (RDR). The ES generates two resonant frequencies corresponding to the dominant even and odd modes. The SR feeder is made of four quarter-wavelength microstrip transformers to reduce the input impedance of the elements and, consequently, maximize the power transferred to each element. Experimental and simulation verifications were conducted on a 54 × 50 × 0.813 mm3 prototype to evaluate the performance of the proposed antenna array, which achieved a VSWR &lt; −10 dB bandwidth of 1 GHz (5.1–6.05 GHz) and axial ratio (AR) &lt; 3 dB of 0.95 GHz (5.1–5.85 GHz). The agreement between the simulated and measured results confirmed the validity of the proposed design.

A New Wideband Circularly Polarized Dielectric Resonator Antenna Loaded with Strips

This paper proposes a novel wideband circularly polarized (CP) dielectric resonator antenna (DRA) loaded with strips. The CP DRA comprises a circular DR, two pairs of driven L-like DR strips with different lengths, and a square ground-plane. To couple the electromagnetic energy to circular DR, an orthogonal cross-slot is used, and a stepped microstrip-line is also used to adjust the impedance matching. Influenced by the concept of deformed DR, two pairs of L-like DR strips of different lengths are inserted into the circular DR as part of the driven element to excite a new axial ratio (AR) resonant point. An antenna prototype is simulated, manufactured, and measured to validate the unique design. The measured results show that the designed antenna has broadband characteristic with a −10 dB IBW of 54% (1.91–3.32 GHz) and 3 dB ARBW of 42.1% (2.10–3.22 GHz).

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.

Novel wideband circularly polarized DRA with squint-free radiation characteristics

A new single-fed circularly polarized dielectric resonator antenna (CP-DRA) without beam squint is presented. The DRA comprises an S-shaped dielectric resonator (SDR) with a metalized edge and two rectangular dielectric resonators (RDRs) blocks. Horizontal extension section is applied as an extension of the SDR, and a vertical-section is placed in parallel to the metallic edge. A vertical coaxial probe is used to excite the SDR and the vertical RDR blocks through an S-shaped metal element and a small rectangular metal strip. The two added RDRs that form an L-shaped DR improve the radiation characteristics and compensate for the beam squint errors. A wideband CP performance is achieved due to the excitation of several orthogonal modes such as TE_{delta 11}^x, TE_{1delta 1}^y, TE_{121}^z, TE_{112}^y, TE_{131}^x, and TE_{311}^y. The experimental results demonstrate an impedance bandwidth of approximately 66.8% (3.71–7.45 GHz) and a 3-dB axial-ratio (AR) bandwidth of about 54.8% (3.72–6.53 GHz) with a stable broadside beam achieving a measured peak gain of about 4.64 , {text{dBic}}. Furthermore, a 100% correction in beam squint value from theta = 41^circ to theta = 0^circ with respect to the antenna boresight is achieved.

A chronological review of circularly polarized dielectric resonator antenna: Design and developments

This article presents a chronological overview of circularly polarized dielectric resonator antennas (CPDRAs). This article provides a comprehensive review about innovation and rapid developments of CPDRAs over the last three and half decades since 1986s. The objective of this article is to highlight the basic concept of CP mechanism in DRA and state-of-the-art developments of CPDRAs in terms of single and multi-point feed for unmodified and modified DR geometries considering different types of excitation mechanism such as microstrip line, coaxial probe, and aperture coupled feed. To give insights into circular polarization, Authors proposed a compact modified CPDRA. It offers simulated bandwidth of 47.5% (2.34-3.80 GHz), measured impedance bandwidth of 50.8% (2.26-3.78), and simulated axial bandwidth of 13% (3.29-3.75 GHz) respectively. Other antenna parameters such as peak realized gain and radiation efficiency are 7.7 dBi and 98% within operating frequency bands, respectively. The proposed outcomes confirm that the proposed CPDRA can be used as a suitable candidate for wireless body area network applications.

Design and Analysis of Circularly Polarized Dielectric Resonator Antenna

The paper presents a novel method for the improvement in the bandwidths by mode merging of the circularly polarized dielectric resonator antenna (CPDRA). The results of improved axial-ratio bandwidth and impedance bandwidth is compared with the previous work. In this design, 50 $$\Omega$$ terminator diverts current in such a way that adjacent exited modes get merged. Also the upper order modes are merged to the lower order modes and a significant enhancement is achieved in overlapping bandwidth. The proposed CPDRA provides axial ratio bandwidth of 53.78% (axial ratio < 3 dB) that completely overlaps by impedance bandwidth (S11 < − 10 dB) of 67.70%. Here, low gain is used for the testing of CPDRA. It can be used as a reference antenna for testing of WLAN and vehicular antennas. The results of prototype CPDRA have been found in close agreement with the simulated one.

Circularly Polarized MIMO Dielectric Resonator Antenna With Reduced Mutual Coupling

A circularly polarized (CP) multiple-input-multiple-output (MIMO) antenna is investigated. This MIMO antenna consists of two identical dielectric resonator antennas (DRAs), which use the same feeding cross slots to generate the same CP fields. Four metal strips are printed on the lateral sides of each DRA to change the rotation direction of the E-field coupled in the passive (coupled) DRA, vary its polarization property, and thus make it opposite (orthogonal) to that of the active (driven) DRA. Thanks to the polarization orthogonality, the isolation between the two CP DRAs is improved significantly, without occupying extra space and destroying the antenna performance. In addition, using this decoupling scheme, the two CP DRAs can operate not only separately but also simultaneously. For verification, a prototype operating at the 2.4 GHz WLAN band is fabricated and measured. In the operating band (2.38-2.52 GHz), the MIMO antenna obtains a maximum improvement of 31 dB and an average improvement of 11 dB in isolation, at a center-to-center distance of 0.4λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> .

A helical shaped broadband circularly polarized dielectric resonator antenna

By modifying the shape of a rectangular dielectric resonator antenna (DRA), a wideband circularly polarized (CP) radiator is introduced. The modified structure is composed of two L-shaped dielectric pieces stacked onto each other. The resulting geometry is similar to a two-turn helix with a rectangular cross section. Placing a coaxial probe adjacent to the sidewall of the DRA excites multiple orthogonal modes in the antenna which in sequence leads to a wideband CP DRA. The special geometry of the DRA provides the required quadrature phase difference between the orthogonal components of the electric fields. The measured input scattering parameter, , is below −10 dB from 3 to 4.6 GHz (42%). Also, the frequency band in which axial ratio (AR) is lower than 3 dB extends from 3.1 to 3.83 GHz (21.07%), which is suitable for WIMAX applications. The measured results of the fabricated prototype are presented to verify the simulations.