Hybrid Dielectric Resonator Antenna Research Articles

A compact dual-band hybrid dielectric resonator antenna for blood glucose sensing and wireless communication

A compact dual-band hybrid dielectric resonator antenna for blood glucose sensing and wireless communication

Wideband millimeter-wave hybrid dielectric resonator antenna array with dual-slot feeding

ABSTRACTA hybrid dielectric resonator antenna (DRA) array is proposed for the wideband millimeter-wave communication. The radiator is composed with a pair of stacked dielectric resonators (DRs), which are H-shaped and Hexagon-shaped DRs, respectively. The dual-slots on the substrate integrated waveguide (SIW) cavity are utilized for higher mode generation in the DRA element. The antenna bandwidth is improved by the stacked DRs and dual-slot feeding. The structural characteristics and key parameters of feeding slots are discussed in detail. The DRA array fed with parallel power distribution feeding network is fabricated and measured to verify the reliability of the simulations, and the simulations and measurements have reasonable consistency. The impedance bandwidth is from 23.55 GHz to 27.28 GHz (14.7%), and the measured gain ranges from 13.1 dBi to 15.7 dBi. The radiation patterns are stable in the operation band. The proposed DRA array has a promising application prospect for 5 G communication system.

Microstrip dual band hybrid directional resonator antenna with volume reduction

This paper presents a novel design of a single-layer, horizontally polarized, dual-band, omni- and multi-directional hybrid dielectric resonator antenna (DRA) feeding through a 50 Ω coaxial connector. The proposed antenna consists of an FR4 substrate, a regular ground plane and a cross-shaped patch. The connector is placed at the middle point of the square ground plane. Above the microstrip patch, four similar solid dielectric resonator elements are placed diagonally. These DRA structures generate the TE111, hybrid HEM22δ modes and put up an ideal magnetic dipole and an electric quadrupole far-field radiation pattern. To verify the idea, an optimized antenna model is fabricated and tested. A reasonable agreement between the measured and simulated results is obtained. The measured impedance bandwidths of the TE111 and HEM22δ modes are 4.26 % (2.9–3.2 GHz) and 4.34 % (4.4–4.6 GHz), respectively. The proposed antenna has a stable omnidirectional radiation pattern at the first resonance frequency and a directional radiation pattern at the second resonance frequency and provides volume reduction.

A Circularly Polarized Hybrid Dielectric Resonator Antenna With Wide Bandwidth and Compact Size

A circularly polarized (CP) hybrid dielectric resonator antenna (DRA) with wide bandwidth and compact size is proposed in this letter. Three CP modes can be combined together for broadband operation, which are the cross-slot mode, the DR mode, and the distributed patch mode, respectively. The cross-slot functions as both a radiator and part of the feeding structure, providing the first CP mode and excites the other two CP modes, respectively. The 2 × 2 distributed patch is inserted inside the DR. The DR and the patch can generate another two CP modes without enlarging the DR size. Through optimization, these three CP modes can be combined to achieve a wide operating bandwidth with a compact size of 0.39 × 0.39 × 0.14 λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> (λ <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free-space wavelength at the center frequency of 3.5 GHz). A prototype was fabricated and measured for demonstration. It has an impedance bandwidth of 38.9% (2.9–4.3 GHz), an axial ratio bandwidth of 34.3% (2.9–4.1 GHz), and a realized gain between 5.6 and 6.7 dBi.

Communication Compact Dual-Band Hybrid Dielectric Resonator Antenna for 5G Millimeter-Wave Applications

In this communication, a new kind of dual-band hybrid dielectric resonator antenna (DRA) with its array design and extended dual-polarized version is presented for fifth generation (5G) millimeter-wave (mm-Wave) applications. The hybrid antenna that integrates three types of resonators of strip, slot, and DRA can generate four resonances in 28 and 39 GHz frequency bands. In this design, the strip and slot modes are used to cover the lower frequency band of 26.41–30.42 GHz, while the TE111 and TE131 modes of the DRA are employed to cover the upper frequency band of 36.05–40.88 GHz. It shows that the 5G mm-Wave bands of n257 and n260 can be covered simultaneously. It should be mentioned that our proposed hybrid antenna has a compact size of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.34\lambda _{01} \times 0.36\lambda _{01} \times 0.1\lambda _{01}$ </tex-math></inline-formula> ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{01}$ </tex-math></inline-formula> means the free-space wavelength at 28 GHz). Based on the compact size of the antenna element, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$1 \times $ </tex-math></inline-formula> 5 antenna array with the capability of beam steering is designed and simulated. Wide steering angles of ±50° and ±40° can be obtained at 28 and 39 GHz frequency bands, respectively. Furthermore, an extended dual-polarized antenna configuration is also described and measured that provides similar two-port impedance and radiation performance with the single-port counterpart.

Machine learning assisted optimization and its application to hybrid dielectric resonator antenna design

Machine learning assisted optimization (MLAO) has become very important for improving the antenna design process because it consumes much less time than the traditional methods. These models' accountability can be checked by the accuracy metrics, which tell about the correctness of the predicted result. Machine learning (ML) methods, such as Gaussian Process Regression, Artificial Neural Networks (ANNs), and Support Vector Machine (SVM), are used to simulate the antenna model to predict the reflection coefficient faster. This paper presents the optimization of Hybrid Dielectric Resonator Antenna (DRA) using machine learning models. Several regression models are applied to the dataset for optimization, and the best results are obtained using a random forest regression model with the accuracy of 97%. Additionally, the effectiveness of machine learning based antenna design is demonstrated through comparison with conventional design methods.

Dual circularly polarized semi‐cylindrical hybrid dielectric resonator antenna for X and Ku ‐band applications

A hybrid dielectric resonator antenna (HDRA) with a single-probe generating circular polarization (CP) simultaneously at X and Ku-bands is presented in this article. A novel hybrid structure of semi-circular patch and semi-cylindrical dielectric resonator (DR) of equal radius are combined with a single-point probe feed to achieve dual-functional wide CP bands. The asymmetric nature of the semi-circle and semi-cylinder produces two orthogonal modes in their respective bands for CP radiation. The measured impedance bandwidth obtained by the proposed structure is 36.49% (3750 MHz) at X-band and 14.23% (2100 MHz) at the Ku-band range of frequencies. Axial ratio (AR) bandwidth of 30.39% (3100 MHz) is obtained at X-band and 13.24% (1950 MHz) at Ku-band. The measured gains are 9.54 dBic at 9.6 GHz and 6.55 dBic at 15 GHz. An excellent agreement between the computed and measured results validates the design of the dual functional circularly polarized HDRA.

A tri-hybrid of [formula omitted]-[formula omitted]-[formula omitted] stair shaped half-cylindrical dielectric resonator antenna (SHCDRA) for wideband wireless communication systems

A novel wideband hybrid dielectric resonator antenna (DRA) made up of three heterogeneous layers of dielectric materials stacked on a rectangular slot patch is proposed in this paper. Here, three half-cylindrical dielectric resonators (DRs) are fabricated using alumina (Al2O3), silica (SiO2) and magnesium zirconate (MgZrO3). Each layer of the DRs is rotated by a certain angle (θ°) in relation to its neighboring layers to improve the DRA’s input impedance and bandwidth. The optimal hybrid Al2O3-SiO2-MgZrO3 stair-shaped cylindrical resonator is excited at a high-frequency medium via a rectangular slot etched on a microwave laminate’s grounding side (∊s = 3.38). It was found that the combination of the stacked DRs at a 30° angle of rotation resulting in a maximum impedance bandwidth of 61.01% (11.96 GHz - 22.46 GHz) with a minimum gain of 3.92dBi. The radiation characteristics in the directions of the H-plane and E-plane were seen to be broadside.

Quasi-Isotropic Hybrid Dielectric Resonator Antenna—Bow-Tie Patch with Harmonic Suppression

This paper proposes a quasi-isotropic hybrid dielectric resonator antenna (DRA) and bow-tie patch with harmonics suppression. The suggested antenna consists of a DRA, a bow-tie patch, and a microstrip seventh-order Chebyshev low-pass filter. By loading a bow-tie patch on the designed DRA, a quasi-isotropic pattern is realized. The seventh-order Chebyshev low-pass filter was applied to the feed line, and harmonics were reduced in the section separate to the operating band to remove harmonics generated by the proposed antenna. The simulated S11 that satisfies below −10 dB is 3.09–3.3 GHz (6.25%), and the measured S11 is 3.10–3.28 GHz (5.64%). The simulated gain difference considering all radiating regions (0∘≤φ≤360∘ and 0∘≤θ≤180∘) is 7.211 dB. Compared with the antenna without a filter, the harmonic gain was reduced by 10.847 and 15.774 dB. The measured gain isolation of the operating band and the second and third harmonics are 10.10 and 18.94 dB, respectively. The proposed antenna is considered to be applicable to applications that require radio wave reception in all directions such as wireless point access points, internet of things and radio frequency identification, and is expected to contribute to reducing the size of the RF system.

Dual-band circularly polarized hybrid dielectric resonator antenna with gain enhancement

This paper presents a dual-band circular polarized (CP) hybrid dielectric resonator antenna (HDRA) with gain enhancement. The fundamental TE111 mode and high-order TE113 mode are excited by the orthogonal CPs in the two frequency bands. This is achieved by cutting four corners along the DRA diagonal and adding a metal strip on the corner. The DRA design procedure is presented to verify its operations. The gain improvement is achieved by loading the water on the top of DRA. This leads to a 1.32 dB improvement on the upper band and have no impact on the lower band. The proposed DRA is fabricated and measured. The results verify its dual-band CP operation at 1.58 GHz (left-hand) and 2.40 GHz (right-band). Two bandwidths of the lower band and upper bands are 20.52% and 21.72%, respectively. The gain improvement is verified from the measurement on both states. The proposed HDRA can be applied for the dual-function communications such as GPS and WLAN.

Dielectric properties of Nd(Ti0.5W0.5)O4 ceramics at microwave frequency for application in hybrid dielectric resonator antenna suitable for LTE/5G

The microwave dielectric properties of Nd(Ti0.5W0.5)O4 ceramics were examined with a view to their application in mobile communication. The Nd(Ti0.5W0.5)O4 ceramics were prepared using the conventional solid-state method. A maximum density of 6.65 g/cm3 was obtained for the Nd(Ti0.5W0.5)O4 ceramic, sintered at 1500 °C for 4 h. Dielectric constants () of 15.4–19.4 and quality factor (Q f) of 3,600–11,100 GHz were obtained at sintering temperatures in the range 1425–1525 °C for 4 h. A Nd(Ti0.5W0.5)O4 ceramic that was sintered at 1500 °C for 4 h had a dielectric constant ( ) of 19.4, a quality factor (Q f) of 11,100 GHz, and a temperature coefficient of resonant frequency () of −48 ppm/°C. The hybrid dielectric resonator antenna consisted of a cylindrical high dielectric constant dielectric resonator and a rectangular slot was implemented. The hybrid dielectric resonator antenna had two resonant frequencies. The lower and higher resonant frequencies were associated with the rectangular slot and dielectric resonator, respectively. Parametric investigation was carried out using simulation software. The proposed hybrid dielectric resonator antenna had good agreement between the simulation results and the measurement results. The proposed hybrid dielectric resonator antenna has frequencies cover sub-6 GHz band and LTE band 3. A 10.2% bandwidth (return loss <10 dB) of 1.77 GHz, and a 9.9% bandwidth (return loss <10 dB) of 3.43 GHz was implemented successfully for application in sub-6 GHz band and LTE band 3.

Reflectarray Resonant Element based on a Dielectric Resonator Antenna for 5G Applications

The performance of a proposed cross hybrid dielectric resonator antenna (DRA) element for dual polarization configuration operating at 26 GHz for 5G applications is presented in this paper. The new cross hybrid DRA unit cell is introduced which combines a cross shape DRA with a bottom loading cross microstrip patch. This technique of a bottom loading cross microstrip patch is chosen as the tuning mechanism (varying the length of the microstrip to tune the phase) instead of changing the DRA dimensions because of their ease of implementation and fabrication. By doing so, high reflection phase range with low reflection loss performance can be obtained, which is essential for a high bandwidth and high gain reflectarray for 5G applications. The design and simulation have been done using commercial software of CST MWS. The reflection loss, reflection phase and slope variation were analyzed and compared. A metallic cross microstrip patch of varying length placed beneath the DRA to act as the phase shifter to tune the phase and give smooth variation in slope with a large phase range. The proposed cross hybrid DRA unit cell provides a high reflection phase range of 342º and 1.8 dB reflection loss. The computed results are compared with experimental results revealing reasonable agreement, thereby confirming the viability of the design.

A compact hybrid dielectric resonator antenna for multiband in wireless applications

This article exhibits the composite dielectric resonator antenna (DRA) for ISM band, Wi-Max and WLAN applications. The proposed DRA is aiming for speech signal and video transmission in the range of wi-max/WLAN. DRA’s are used in many digital signal processing applications because they are capable of locating signal sources. Microstrip feed line excites the exhibited structure. A circular dielectric resonator antenna with circular ring and cross shaped strip is designed to generate tri-band characteristics. The proposed antenna structure cover three different frequency bands, i.e. 1.85–2.5 GHz, 2.97–3.92 GHz and 4.821–5.9 GHz, with the fractional bandwidth of 30.1%, 27.5% and 20.9% respectively. An ISM band, Wi-max as well as WLAN are being utilized for correspondence of continuous traffic including speech signal, video and information to supervise medical issues in wireless body area networks (WBAN) advancement. To strengthen the resonator appearance as well as miniaturize the volume, the customized circular metallic component and cross shaped strip are stacked onto the substrate. The simulated results are verified by using fabricated antenna and the results are compared. The proposed model is strongly encouraging the wireless applications.

A Low-Profile Hybrid Multi-Permittivity Dielectric Resonator Antenna With Perforated Structure for Ku and K Band Applications

A wideband hybrid dielectric resonator antenna (DRA) consisting of a rectangular slot patch and a perforated stacked cylindrical dielectric resonator (DR) is proposed. A rectangular slot was etched on the grounding side of a microwave laminate (ϵ s = 3.38) to excite the hybrid resonator at a high frequency. The stacked DR used consists of three different layers of permittivity, in which air-cavity was introduced internally to form a perforated structure. With a proper stacking arrangement of the perforated DRs on top of the rectangular slot, their operating frequencies were merged together to produce a wideband hybrid DRA. It was found that the combination of the stacked DR with perforated structure in the hybrid element had yielded an impedance bandwidth of as wide as 75.8% (12.2 GHz - 27.1 GHz). Huge improvement in bandwidth was successfully achieved in this study in comparison to that without a perforated structure of only 48.9%. Simulation of the antenna was performed in time domain using Computer Simulation Technology (CST) and was subsequently verified with the measurement results. The average simulated and measured directivity of the antenna were recorded to be 6.05 dBi and 5.65 dBi, respectively, with a stable broadside radiation throughout the operating range of frequency. The radiation characteristics were seen to be broadside in both the E-plane and H-plane.

An Electronically-Switched Frequency-Agile Hybrid Dielectric Resonator Antenna With a Fixed Reconfigurable Circularly Polarized Band

In this article, an electronically-controlled frequency-agile hybrid dielectric resonator antenna is presented that also produces a reconfigurable circularly polarized (CP) wave over a specific frequency range. Two L-shaped metallic strips are placed adjacent to a partial ground plane that can be shorted/detached in four combinations using two PIN diodes (D1 and D2). Frequency reconfigurability is achieved by switching from both OFF to at least one ON state to yield a single and dual-band responses for the former and latter, respectively. The Eigen mode simulation reveals that the upper-band is mainly attributed to the quasi-TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">δ21</sub> mode of the rectangular dielectric resonator. The lower-band in one and two ON-states arises due to the dielectric-loaded monopole antenna and the strip-loaded partial ground plane, respectively. The ON-OFF state produces a right-handed CP wave at the lower band that can be reconfigured to a left-handed CP wave by switching to OFF-ON state. A fabricated sample is measured and simulation results are validated. The measured -10 dB impedance bandwidths for OFF-OFF, ON-ON, OFF-ON, and ON-OFF are 13.31% (4.42-5.05 GHz), 11.30% (2.17-2.43 GHz)/27.43% (3.68-4.85 GHz), 30.64% (2.46-3.35 GHz)/17.94% (4.16-4.98 GHz), and 26.57% (2.48-3.24 GHz)/18.7% (4.12-4.97 GHz), respectively. The measured 3 dB axial ratio bandwidths are 12.20% (2.54-2.87 GHz) and 10.95% (2.59-2.89 GHz) when D1 and D2 are turned-ON alternatively.

Performance analysis of a hybrid dielectric resonator antenna in frequency and time domains

This article presents a compact hybrid X-band radiator, by combining the multiple resonances of two resonating and radiating structures, namely (a) a cylindrical dielectric resonator (CDR) and (b) a new type of slot geometry along with a U-shaped microstrip feedline. Excitation of a few higher order modes in CDR structure is also observed and further investigated. The detailed performance analysis of the proposed geometry has been carried out both in frequency and time domains. Some design guidelines have been formulated which enable the design of the antenna for different bands. The proposed structure offers 46.3% (S11 ≤ −10 dB and Voltage Standing Wave Ratio (VSWR) < 2) (measured) impedance bandwidth and about 4.5 dBi peak gain. The proposed antenna has the potential to be an ideal candidate for X-band sensor applications.

Wideband circularly polarized hybrid dielectric resonator antenna with bi‐directional radiation characteristics for various wireless applications

In this article, a wideband circularly polarized (CP) dielectric resonator (DR) over an asymmetric-slot radiator based hybrid-DR antenna is proposed with bi-directional radiation characteristics. Bi-directional CP radiation of the dual sense is obtained using a rectangular-DR over asymmetric-rectangular-slot radiator with L-shaped feed line. The asymmetric-slot radiator feed by L-shaped stub with the coplanar waveguide is used for generating two orthogonal modes, namely TE x δ11 and TEy1δ1 in the combined (rectangular-DR and asymmetric-slot radiator) hybrid-DR antenna, which is verified by the distribution of electric field inside the rectangular DRA. The measured reflection coefficient bandwidth (S11 < −10 dB) and axial ratio (AR) bandwidth (AR < 3 dB) of the hybrid-DR antenna are 80.5% (1.87-4.39 GHz) and 43.8% (1.75-2.73 GHz), respectively. The antenna radiation is in the broadside (θ = 0°, ϕ = 0°) direction as well as in the backside (θ = 180°, φ = 0°) direction with equal magnitudes in both the directions. Right-handed and left-handed CP waves are achieved respectively, in the boresight (+Z) and the backside (−Z) directions. The proposed CP hybrid-DR antenna gives an average gain of 3.55 dBic and radiation efficiency of 95.0% in both directions. The proposed antenna covers various wireless useful bands such as ISM 2400 band, Wi-Fi, Bluetooth, and Wi-MAX (2.5-2.7 GHz).

Triple-Band Dual-Sense Circularly Polarized Hybrid Dielectric Resonator Antenna.

In this paper, a triple-band dual-sense circularly polarized (CP) hybrid dielectric resonator antenna is proposed. A modified hexagonal dielectric resonator (DR) is top-loaded with a square microstrip ring (SMR). A vertical-tapered-strip connected to a 50- microstrip line is used to excite the proposed antenna. It is found that the lower and central CP bands correspond to left-handed circular polarization and are produced by the TM and TE modes of the SMR and modified hexagonal DR, respectively. The upper CP band is formed by the combination of the quasi-TM mode of the SMR and quasi-TE mode of the DR that exhibits right-handed circular polarization. The measurement results of the fabricated prototype show triple-band response for |S −10 dB with impedance bandwidths (IBWs) of 17.4% (1.75–2.03 GHz), 28.13% (2.23–2.96 GHz), and 2.97% (3.65–3.76 GHz) in the lower, central, and upper bands, respectively. The measured 3 dB axial ratio bandwidths lying within −10 dB IBWs are 3.69% (1.86–1.93 GHz), 5.46% (2.67–2.82 GHz), and 2.15% (3.68–3.76 GHz) along with the peak gains of 5 dBic, 5.28 dBic, and 2.36 dBic in the lower, central, and upper bands, respectively.

Single Band Notched Characteristics UWB Antenna using a Cylindrical Dielectric Resonator and U-shaped Slot

In this manuscript, a novel hybrid dielectric resonator antenna for ultrawideband applications is designed, and single notched bands performance is proposed . The circle radiating patch is printed on FR4 substrate 1.64 mm thickness and loss tangent tan� =0.02, and is fed by coplanar waveguide. The size of the UWB antenna is minimized to 50-40 mm 2 . The operation bandwidth of the designed antenna is from 3.1 GHz to over 12 GHz. WIMAX Band notches characteristics of antenna to reject, is realized by etching U Shaped slot in the radiating patch. The center notch frequency can be adjusted from 3.4 to 4.5 GHz, by changing the position of cylindrical Dielectric Resonator. The band notched characteristics, VSWR, and radiation patterns are studied using CST and HFSS high frequency simulators

Compact dual-band hybrid dielectric resonator antenna loaded with magnetic-LC resonator

This article presents a compact dual-band hybrid dielectric resonator antenna for wireless communication systems. The proposed design uses a square dielectric resonator loaded with magnetic-LC resonator (complementary of electric-LC resonator) to achieve miniaturization and dual-band operation. Based on the parametric analysis, it is reveled that the two operational bands could be designed independently. The proposed antenna operates at 3.6 and 5.25 GHz with impedance bandwidths of 3.9% (3.53–3.67 GHz) and 3.24% (5.17–5.34 GHz), respectively. The antenna radiates with similar radiation pattern at both the operating frequencies with the cross polarized fields better than 20 dB. The peak gain of the antenna is 6.27 and 6.35 dBi at lower and upper operating frequency, respectively. The proposed antenna is suitable for worldwide interoperability for microwave access and wireless local area network band applications.