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This investigation introduces a MIMO antenna using cylindrical shaped dielectric resonators and discusses both the design and implementation approaches. The proposed antenna design employs a CSRR structure and L-shaped metallic reflectors to improve isolation across many frequency bands. The typology operates at five different frequency ranges: 2.48, 3.92, 5.36, 7.4, and 8.56 GHz. It provides isolation levels of 39, 52.5, 33.8, 42.9, and 37.2 dB, respectively. The semi-circular tapered feed enables for circular polarization between 5.3 and 5.75 GHz. The simulated results indicate that the specified antenna is appropriate for usage in five frequency ranges: 2.1–2.6, 2.7–4.4, 4.9–5.8, 6.9–7.8, and 8.1–9.1 GHz. In a multiple-input multiple-output configuration, antenna performance is evaluated using a variety of diversity indicators, including the envelope correlation coefficient, mean effective gain, diversity gain, channel capacity loss, and total active reflection coefficient. Both simulations and measurements reveal that the proposed antenna can handle Wi-Fi 6, Wi-Max, and W-LAN services, including X-band. [ABSTRACT FROM AUTHOR]

The frequency diverse array (FDA) is a very interesting technique in wireless communications. Many research papers are introduced in this field. A lot of them is concerned with linear point sources array. In this paper, a design of a time-modulated planar frequency diverse array architecture is proposed for tracking single or multi-target for the first time. The time-modulation array (TMA) and FDA are combined for detecting single and multi-target. The effectiveness of this combined scheme is demonstrated through simulation results that compared with a point source case to show its superior performance. Authors introduce planar FDA array instead of linear FDA array and realize the planar array using cylindrical dielectric resonator antenna array (CDRA). A planar array consists of 8 × 8 CDRA is used to enable the detection of single target/multi-target. The operating frequency of the antenna is set at 10 GHz, aligning with its applications in the FDA radar. The radiation characteristics of the CDRA antenna element are introduced. High maximum gain of 6 dBi is achieved with a remarkably high efficiency. A set of representative results is reported and analyzed to assess the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

In this paper, a Substrate-Integrated Waveguide (SIW)–based Cylindrical Dielectric Resonator Antenna (CDRA) is designed for 6G THz applications. This antenna provides a Quad-band response at 2.14 THz, 3.41 THz, 5.61 THz, and 9.02 THz respectively. The unique feature of the proposed SIW-CDRA is its ability to exhibit Circular Polarization (CP) behavior across three frequency bands. Graphene material is added onto the top of the proposed CDRA to achieve tunability in the antenna's resonant frequency. CP tuning is also achieved by varying the graphene potential of the antenna. Furthermore, this proposed antenna shows both Right Hand Circular Polarization (RHCP) and Left Hand Circular Polarization (LHCP) behavior at different resonant frequencies. The antenna exhibits a maximum gain of 6.97 dB and a maximum radiation efficiency of 84.53%. Notably, the antenna showcases a 3 dB Axial Ratio (AR) bandwidth of 11.05% (1.968–2.195 THz), 4.58% (5.483–5.734 THz), and 5.22% (8.843–9.313 THz) is achieved. Moreover, the CDRA generates two higher-order modes, specifically HEM11δ at 5.61 THz and HEM12δ at 9.02 THz. Additionally, the antenna exhibits a unique feature of converting multiband response to wideband response by changing the length of the aperture slots. All these results show that the proposed multiband SIW with CDRA is unique and suitable for THz applications. [ABSTRACT FROM AUTHOR]

This research examines the performance of two Z-shaped dielectric resonator antenna designs that employ silicon substrate material and operate at a frequency of 10 terahertz. CST software was used to simulate and create a two-Z shape DRA. Results of enhanced gain are analyzed and compared with earlier research. The suggested Two Z shape DRA has a gain of 7.31 dB and a return loss of -15.9 dB.The two Z-shaped dielectric resonator antennas have an impedance bandwidth of 66.66%.The VSWR of two Z-shaped dielectric resonator antennas is around 2 dB, which is acceptable. This proposed approach may be suitable for a wide range of communication applications, including wireless and terahertz applications. [ABSTRACT FROM AUTHOR]

A novel dual band tunable terahertz (THz) circularly polarized dielectric resonator antenna (CPDRA) is designed and numerically studied. Hybrid Silicon-Graphene materials are employed as radiator with cross-slot shaped aperture coupled feed, enabling tunable linearly and circularly polarized radiation. Silicon is a good material as dielectric resonator with its operation in the THz regime due to lack of absorption, cheaper to grow and machine. Cross shaped slots of appropriate dimensions are engraved in the centre of the ground plane to split the fundamental mode of the rectangular DR into two near degenerate orthogonal modes having quadrature phase difference. As a result, circular polarization is obtained in the upper passband. Introducing cross slot also helped to improve the impedance matching and dual band operation is achieved with linearly polarized response in lower band and circularly polarized response in the upper band. By adjusting the chemical potential of graphene, frequency tunability in the both the operating bands is obtained, without changing the physical geometry of the antenna. The proposed antenna operates with 10 dB impedance bandwidth of 4.24 \% (2.31–2.41 THz) and 12.1 \% (3.11–3.51 THz) and 3 dB axial ratio bandwidth of 3.54 \% (3.33–3.45 THz). The antenna parameters are calculated and gain of 6.11 dBi and 5.8 dBiC in lower and upper band, respectively and radiation efficiency of 96.5 \% in both operating bands is obtained. This hybrid radiator-based THz CPDRA shows great potential in the development of tunable THz devices and could pave a path for new researchers. [ABSTRACT FROM AUTHOR]

This communication discusses and examines a dual port filtering hybrid (Silicon-graphene) based antenna. The main appearances of the designed THz radiator are: (i) a modified circular patch created HEM 11 δ x and HEM 11 δ y inside silicon ceramic, which in turn created a circularly polarized wave from 2.59 to 2.89 THz (axial ratio ≤3 dB); (b) a defected ground structure (DGS) along with patch creates band pass filtering features (5.0 dBi within the operating band and −15 dBi outside the operating band) within the operating band; and (c) coating of graphene material over the ceramic adds the re-configurability feature in proposed radiator. The designed radiator works effectively in between 2.49 and 3.29 THz (|S11|≤ −10 dB) with more than 25 dB isolation (due to orthogonal orientation). Due to the aforementioned features, the designed radiator is employable for different wireless THz applications. [ABSTRACT FROM AUTHOR]

This paper presents a novel Multiple Input Multiple Output (MIMO) circularly polarized stacked Cylindrical Dielectric Resonant Antenna design integrated with graphene and polarization switching, propelling significant advancements in THz wireless communication. The proposed antenna achieved a wideband Impedance bandwidth of 3.12 THz, complemented by an overlapping Axial Ratio (AR) bandwidth (ARBW) of 2.01 THz, respectively. The antenna incorporates a new Defected Ground Structure to generate a wideband frequency response. The integration of graphene on top of the DRAs further enhances the antenna's performance, significantly boosting gain and radiation efficiency. A standout feature of this antenna is its seamless switching capability between Left-Hand Circular Polarization and Right-Hand Circular Polarization, making it highly adaptable for diverse communication scenarios. Additionally, the resonant frequency of the antenna can be precisely tuned by varying the graphene chemical potential (µc), offering enhanced flexibility. The paper also investigates a 2 × 2 MIMO configuration with excellent performance parameters, showcasing its suitability for THz wireless communication. Furthermore, the proposed antenna exhibits very high isolation between the ports by varying µc. The key features of the antenna include wideband frequency response and AR response, polarization switching, tuning of resonant frequency, high gain, and high efficiency. These advantages mark a significant milestone in THz wireless communication, setting new benchmarks for efficiency, adaptability, and overall performance in this rapidly evolving field. [ABSTRACT FROM AUTHOR]

This paper presents a high gain diagonally-probe-fed multi-layered dielectric resonator antenna (DPF-ML-DRA) designed for 77 GHz automotive radar applications. A comparison with the conventional probe-fed ML-DRA demonstrates that the proposed DPF-ML-DRA achieves higher antenna gain by 1 dB. The sub-array utilizing the proposed DPF-ML-DRA is tailored to meet specific radar system requirements, including a broad impedance bandwidth (> 5 GHz), high antenna gain (> 12 dBi), and wide half-power beamwidth (> ± 60°). Simulated results validate that the sub-array performance meets the aforementioned antenna requirements. To attain high azimuthal and elevational angular detecting resolution, 3 sub-arrays with 12 DF-ML-DRA for the Tx channel and 4 sub-arrays with 10 DF-ML-DRA for the Rx channel were designed and simulated. The fabricated radar system underwent field testing, demonstrating a maximum range of up to 160 m and a field of view of 120° for 100 m. Remarkably, the proposed DPF-ML-DRA exhibits equivalent radar performance while featuring a smaller form-factor compared to commercially available state-of-the-art automotive radar systems. Consequently, the proposed DPF-ML-DRA proves to be well-suited for 77 GHz automotive radar applications. [ABSTRACT FROM AUTHOR]

The research describes a novel method for boosting gain in quantum CDRAs that involves replacing the silicon dioxide substrate with a Teflon substrate. The enhanced gain results are analyses and compared to earlier research findings. CST software was used to create and simulate a quantum CDRA. The antenna structure includes cylindrical dielectric resonators with a greater antenna gain at a frequency of 504 THz. The quantum CDRA has an impedance bandwidth of 9.41 percent. The reported quantum CDRA has a gain of 6.3 dB and a return loss of − 27.5 dB. Terahertz applications are feasible with the suggested quantum CDRA. [ABSTRACT FROM AUTHOR]

This review article provides a detailed overview of current techniques in the field of Dielectric Resonator Antennas (DRA). The primary aim of study aims electrical size downsizing, retrofitting bandwidth to meet commercial needs, and radiation pattern stability by managing the modes in the DRA with the evolution starting from rectangular shape to contemporary investigations. Various research strategies for miniaturizing the physical and electrical size, mode excitation by various mechanisms such as a probe, microstrip, slot, and others, along with increasing bandwidth and radiation characteristics have been mentioned. In this review, the innovative geometries and fractal notions introduced to the DRAs are also discussed. [ABSTRACT FROM AUTHOR]

This paper proposes a compact dielectric resonator-based high gain dual-band hybrid antenna. The antenna is proposed to work in a dual ISM (industrial, scientific, and medical) band, i.e., at 2.40 - 2.48 GHz and 5.725 - 5.875 GHz. The designed antenna can work as a radiator in the lower band (2.37 - 2.49 GHz) and as a sensor in the upper band (5.34 - 6.00 GHz). The non-invasive blood glucose sensing application is chosen at a higher frequency band, and a lower band is chosen for wireless communication. From a single transmission feed line, both frequency bands are generated by the fundamental mode T M 10 of radiating slot and H E M 11 mode inside cylindrical DRA, respectively. The designed antenna is optimized and simulated to get the best possible results in terms of S-parameter, bandwidth, gain, radiation pattern, efficiency in a lower band, and sensitivity toward blood permittivity in a higher band. This work performs regression analysis and fasting experiments for blood glucose sensing. The link budget analysis is also done at different data rates for wireless communication. The Specific absorption rate (SAR) value is calculated in finger tissue to ensure safety. The simulated and measured results of the designed antenna suggest that it can be used for non-invasive blood glucose sensing and wireless communication applications. To the author's knowledge, no antenna was reported prior for radiating as well as sensing applications. [ABSTRACT FROM AUTHOR]

In this paper, a two-port alumina-based filtering antenna is designed and investigated. The feeding structure of the proposed antenna creates dual radiation nulls inside the cylindrical ceramic, which in turn produces the filtering characteristics. A metasurface is suspended over the two-port radiator to convert linear waves into circular waves. The designed metasurface also reduces the mutual coupling between two ports by an amount of −15 dB because it acts as a single negative material. Experimental results are in good agreement with simulated outcomes. It works efficiently between 2.31 GHz and 2.62 GHz with an isolation level of more than 35 dB. 3 dB axial ratio is obtained between 2.4 GHz and 2.61 GHz. Out of the frequency band, the gain value is less than −15 dB, while it is 4.28 dBi in the functioning frequency range. Stable radiation properties make it suitable for B41/n41 (2.5/2.6 GHz) applications.a standard retrieval procedure. [ABSTRACT FROM AUTHOR]

This work studies the dielectric properties in the microwave region (MW) of the Ba2TiSi2O8 (BTS) ceramic with TiO2 additions and its applications as a dielectric resonator antenna (DRA). In this study, structural characterization through x-ray diffraction (XRD) is performed and the Rietveld refinement is used to confirm the phases formed. Analysis of the morphology of the materials is performed using scanning electron microscopy (SEM). The resonant frequency temperature coefficient (τf) reveals a variation from − 47.0 ppm°C−1 to + 16.5 ppm°C−1. The dielectric properties in the MW region reveal an increase in the dielectric permittivity (εr) and a decrease in the loss tangent (tanδ) of the samples. Numerical simulation shows good fits of the experimental data, with gain and directivity standing out, ranging from 4 dBi to 6 dBi and radiation efficiency below 80%. The results demonstrate that the samples can operate in C-band electronics, Wi-Fi devices, meteorological radar systems, etc. [ABSTRACT FROM AUTHOR]

In this communication, dual-band circularly polarized radiator is structured and investigated in THz regime. The unique properties of proposed radiator are: (1) dual band circularly polarized aerial is designed in THz regime; (2) application of graphene layer over ceramic makes the radiator reconfigurable in terms of both frequency range and axial ratio; and (3) asymmetrical dumbbell shape helps to create dual radiating mode i.e. HEM11δ and HEM12δ mode. For verification, optimized outcome obtained from Ansys HFSS is compared with CST-MWS. There is good agreement between them. The designed radiator works well between 2.4 THz–3.0 THz and 4.4 THz–5.15 THz. The value of axial ratio below 3-dB is achieved between 2.6 THz–2.8 THz and 4.6 THz–4.8 THz, respectively. Broadsided radiation patterns and good gain characteristics create the designed aerial suitable for different wireless applications in the optical domain. [ABSTRACT FROM AUTHOR]

This work proposes a novel dielectric resonator antenna design for 5G-based IoT applications that operates in the sub-6 GHz frequency range. The DR antenna is built on a 1.6-mm-thick FR-4 substrate with dimensions of 30*50 mm2. The proposed dielectric resonator antenna is made of alumina and is excited using a microstrip feedline of 50 Ω. Because of the hybrid arrangement of cylindrical and rectangular dielectric resonator elements on the FR4 substrate, this proposed structure has improved the radiation mechanism. The antenna design process begins with creating the antenna in the Ansys HFSS EM simulator, which is then optimized using machine learning based on the antenna geometry's target factors. A data set of 2625 sample data values is generated in HFSS and fed to various machine learning algorithms for further optimization based on data trends. Post-optimization, the antenna design is fabricated and tested. The proposed antenna offers a wide bandwidth of 1.1 GHz between 3.5 and 4.6 GHz and resonates at 3.9 GHz making it suitable for 5G sub-6 GHz IoT applications. [ABSTRACT FROM AUTHOR]

A polarization reconfigurable tri-band dielectric resonator antenna (DRA) is designed and numerically investigated for THz applications. The designed rectangular DRA made of silicon is excited by a silver nanostrip feed. The unique feature of the proposed DRA is the incorporation of dual split ring resonators (SRRs) connected with graphene layer. The SRRs are used to excite orthogonal modes required to achieve circular polarization response in the THz bands. The tunability in polarization is achieved by varying the chemical potential of the graphene layer used to connect the outer ring of the two SRRs. The proposed circularly polarized DRA (CPDRA) achieves a triple band with an impedance bandwidth of 4.96–5.52 THz, 6.85–7.12 THz, and 8.5–9.4 THz. The dual 3-dB axial ratio bandwidth of 5–5.6 THz and 8.8–9.4 THz with a peak gain of 7 dBi is obtained by the proposed design. The CPDRA exhibits stable left-hand circular polarization radiation pattern with RHCP below 15 dB in the boresight directions. This novel approach for tuning the polarization and triple band impedance bandwidth makes the proposed design a suitable candidate for THz communication, imaging, and sensing applications. [ABSTRACT FROM AUTHOR]

A new ultra-wideband two-port MIMO Dielectric Resonator Antenna (DRA) based on defected ground structure is introduced for Terahertz (THz) frequency applications. The antenna utilizes two silicon-based Dielectric Resonators (DRs) as radiators. It exhibits an ultra-wideband response with a bandwidth of 14.5 THz (9.5 THz–24 THz) and offers high isolation of ≤ − 20 dB across the operating frequency range. Additionally, it achieves dual-band circular polarization with a 3-dB Axial Ratio (AR) Bandwidth (ARBW) of 37.55% (9.82 THz–14.36 THz) and 30.87% (16.9 THz–23.07 THz) respectively. The antenna demonstrates a high radiation efficiency of 95.02% and a peak gain of 8.76 dB. By varying the feed lengths, the antenna enables polarization reconfigurability, which is advantageous for future THz wireless systems. Moreover, the antenna exhibits improved MIMO diversity performance, characterized by parameters such as CCL < 0.5 bps/Hz, MEG ≤ − 3 dB, TARC ≤ − 10 dB, DG ≈ 10 dB, and ECC < 0.01. To enhance its performance, the DRA is coated with graphene, enabling tunability in frequency response and axial ratio (AR) response, thereby increasing the Impedance Bandwidth (IBW). These unique characteristics make the proposed MIMO DRA well-suited for various THz Nanodevice applications, including Terahertz wave Radar, Health care, Astronomical radiometric applications, and future THz wireless communication. [ABSTRACT FROM AUTHOR]

This article exemplifies about the design of a low profile Rectangular Dielectric Resonator Antenna (RDRA) associated with a flagpole shaped microstrip feeding technique for bandwidth enhancement. The proposed 'Six' shaped DRA works at X band and Ku band frequencies and offers a broad bandwidth of 57.11% from 8.82 to 14.6 GHz with limited volume of 2.5 mm. A flagpole shaped microstrip feeding contributes superior coupling and improves impedance bandwidth to its maximum. The proposed antenna can serve as an excellent candidate for high frequency applications such as satellite broadcast services and space shuttle communication. It is very useful for both uplink (10.95–11.7 GHz) and downlink frequencies (14–14.6 GHz) of Ku band VSAT (Very Small Aperture Terminal). The new 'Six' shaped DR structure and the modified microstripline feeding technique induce TE111 and TE112 modes of RDRA. The closely spaced resonant modes get coupled and accelerate the process of bandwidth enhancement. Results show that there is an achievement of fair agreement between measured and simulated results of the proposed antenna. [ABSTRACT FROM AUTHOR]

The effect of doping of Co2+ and Sn4+ in Ba0.5Sr0.5Fe12-2xO19 hexaferrite with different concentrations (x = 0.2, 0.4, 0.6, 0.8, and 1.0) was studied by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), complex impedance spectroscopy, and analyzed as a dielectric resonating antenna (DRA) at room temperature. The samples were produced and sintered by the solid-state reaction method. Their structure appeared from the M-phase type while their increase in grain size evidenced a dependency on Co-Sn content. The dielectric constant and loss tangent, inferred from impedance spectroscopy, also decreased with the corresponding increase in doping. The real and imaginary impedance decreased with the frequency increment. An electrical equivalent circuit using the Resistance-Constant Phase Element (R-CPE) association was thus proposed, the best-simulated components fitting with the observed structural and microstructure properties. It enabled a better understanding of the microstructure through simulated values of grain/grain boundaries and its effect on tuning the electrical properties in the low-frequency regime. The ferrite characteristics were tested for dielectric resonator antenna applications owing to their good inherent behavior than microstrip patch antenna. Measurement of the radiation efficiency, gain and bandwidth parameters of all the produced ceramics showed that the non-doped one (x = 0.0) exhibits the optimum values: 99.91%, 4.24, and 2.89 GHz, respectively, making the most valuable for antenna applications. [ABSTRACT FROM AUTHOR]

This article presents a 3D-printed cylindrical dielectric resonator antenna operating at 5.8 GHz that achieves circular polarization by integrating a fully dielectric parasitic helix with a higher permittivity than the cylindrical resonator. The antenna polarization can be right-handed or left-handed depending on the turning sense of the helix. An extensive parametric study was done for the helix design to evaluate the effects of the dimensions and dielectric constant of the helix over the matching and axial ratio of the antenna. The manufacturing is made using low-loss dielectric filaments and a low-cost 3D printer. Simulation and measurement results show that both antennas are well-matched and operate with the corresponding circular polarization, with an axial ratio bandwidth compatible with UAV applications. [ABSTRACT FROM AUTHOR]

This article presents a historical overview of research focused on dielectric resonator antennas (DRAs) over the past few decades. The dielectric resonators (DR) provide the most attractive features as antenna elements, including high radiation efficiency, large bandwidth, small size, most accessible coupling schemes, etc. The essential characteristics of DRAs are described in detail by reviewing the most potent methods for antenna feeding and size reduction. Moreover, recent design solutions for improving the realized gain of particular DRAs are analyzed. Numerous application-oriented DRAs are discussed in this article which helps to make the survey more effective. The DR antenna was utilized in various applications because of the low cost, enlarged design flexibility, and reduced loss. The requirement of 5G communication is fulfilled by using the appropriate antenna with enhanced bandwidth. For 5G communications, a microstrip patch antenna (MSA) is considered a better choice. Also, a low profile wide band hybrid stacked DRA can be utilized for Ku and K band applications. In millimetre wave application, the reduction of ohmic losses is considered the primary goal. Thus, the millimetre wave applications select the DRAs with minimum ohmic losses. Also, the gain enhancement of DRA through different shapes, feed coupling schemes, and various modes are discussed. Finally, the simulation results of several existing approaches are analyzed in terms of gain, radiation pattern, reflection coefficient, radiation efficiency, and return loss. [ABSTRACT FROM AUTHOR]

This article proposes a new method for exciting surface waves in dielectric rod antennas using dielectric resonator antennas. The method involves housing a rectangular dielectric resonator antenna with a dielectric constant of 10.2 inside a hollow cylindrical dielectric rod antenna made of Teflon. By exciting the TE 111 y and TE 113 y modes of the dielectric resonator antenna, a surface wave can be launched along the Teflon tube. This method offers the advantage of integrating the dielectric rod antenna with planar circuits, where maximum radiation in the direction normal to the board is desirable. Compared to other planar feeding methods, this technique leads to lower back lobe and sidelobe levels. I fabricated the proposed structure and conducted tests to measure its performance. The measured results show an impedance bandwidth of 22% from 7.35 to 9.4 GHz and a maximum gain of 14 dB. Additionally, the simulated radiation efficiency of the proposed antenna in the entire band is above 90%. [ABSTRACT FROM AUTHOR]

Rectangular Dielectric Resonator Antenna (RDRA) is utilized for the wireless communications system because of its miniaturized size and low profile. This paper presents a design and simulation of slotted RDRA for satellite communication. The major aim of the work is to attain a high gain and radiation efficiency. Hence, the parasitic patch is introduced in this work to achieve this requirement. In this work, the RDRA is designed with a compact size of 10 × 10 × 3 mm, which operates at 17.04 GHz for satellite communication applications. The design is evaluated on the substrate ROGERS RT DUROID 5880, and the antenna comprises Alumina (Al2O3) ceramic material. The slotted design provides better impedance bandwidth and gain. The entire work is simulated in Ansys HFSS software. The performance measures like gain, return loss, radiation pattern, VSWR and directivity are simulated and fabricated. The proposed design provides circularly polarized characteristics at 3 dB and better radiation efficiency of 100%. At last, the fabricated design prototype is analyzed and provides better performance. The simulated and fabricated outcomes proved that the proposed slotted RDRA is efficiently exploited for satellite communication. [ABSTRACT FROM AUTHOR]

A theoretical method for calculating the fields inside the Graphene Loaded Equilateral Triangular Dielectric Resonator Antenna (TDRA) and obtaining the resonance frequency of its different radiation modes is presented. The upper surface of the antenna is covered with a graphene sheet, which acts as an impedance surface. By varying the chemical potential of graphene, the value of its surface impedance changes and thus the fields of the modes inside the TDRA and their resonance frequencies are affected. Using the theoretical method and by simulating the structure, the changes in the resonance frequency of several radiation modes of TDRA have been investigated and compared, and a good match between the results has been obtained. In another part of the article, a graphene loaded TDRA is designed using the proposed design formulas and its reflection coefficient and radiation patterns are obtained by simulating the structure. [ABSTRACT FROM AUTHOR]

A novel high-isolation, monostatic, circularly polarized (CP) simultaneous transmit and receive (STAR) anisotropic dielectric resonator antenna (DRA) is presented. The Proposed antenna is composed of two identical but orthogonally positioned annular sectoral anisotropic dielectric resonators. Each circularly polarized (CP) resonator consists of alternating stacked dielectric layers of relative permittivities of 2 and 15 and is excited by a coaxial probe from the two opposite ends to have left and right-hand CP. Proper element spacing and a square absorber are placed between the resonators to maximize Tx/Rx isolation. Such a structure provides an in-band full-duplex (IBFD) CP-DRA system. Measurement results exhibit high Tx/Rx isolation better than 50 dB over the desired operating bandwidth (5.87–5.97 GHz) with a peak gain of 5.49 and 5.08 dBic for Ports 1 and 2, respectively. [ABSTRACT FROM AUTHOR]

The coupling between the ports of a two-port device implemented based on a single dielectric resonator (DR) of silicon material can be controlled to develop the terahertz multi-input-multi-output (MIMO) antenna and a filter. The ground plane of device is modified by engraving a circular slot for obtaining the function of a two-port MIMO dielectric resonator antenna with isolation between the ports as 18.3 dB. The radiating surface of DR is then coated with graphene material to further enhance the level of isolation up to 40.91 dB. Graphene coating also provides the tunable antenna response by varying the applied external DC field on graphene. The antenna can offer pattern diversity with envelop correlation coefficient less than 0.01 and diversity gain 9.94 in the passband. The isolation of this two-port antenna can further be enhanced up to 49 dB by covering the graphene layer with metal coating. Moreover, the coupled power between the ports of the device can be controlled to implement a bandpass filter by engraving a circular slot in graphene layer and filling it with metal. The amount of the power coupled between the ports of the filter can be controlled by varying the chemical potential of graphene. [ABSTRACT FROM AUTHOR]

Objective: To determine whether a multi-feed, loop-dipole combined approach can be used to improve performance of rectangular dielectric resonator antenna (DRA) arrays human brain for MRI at 7 T. Materials and methods: Electromagnetic field simulations in a spherical phantom and human voxel model "Duke" were conducted for different rectangular DRA geometries and dielectric constants εr. Three types of RF feed were investigated: loop-only, dipole-only and loop-dipole. Additionally, multi-channel array configurations up to 24-channels were simulated. Results: The loop-only coupling scheme provided the highest B1+ and SAR efficiency, while the loop-dipole showed the highest SNR in the center of a spherical phantom for both single- and multi-channel configurations. For Duke, 16-channel arrays outperformed an 8-channel bow-tie array with greater B1+ efficiency (1.48- to 1.54-fold), SAR efficiency (1.03- to 1.23-fold) and SNR (1.63- to 1.78). The multi-feed, loop-dipole combined approach enabled the number of channels increase to 24 with 3 channels per block. Discussion: This work provides novel insights into the rectangular DRA design for high field MRI and shows that the loop-only feed should be used instead of the dipole-only in transmit mode to achieve the highest B1+ and SAR efficiency, while the loop-dipole should be the best suited in receive mode to obtain the highest SNR in spherical samples of similar size and electrical properties as the human head. [ABSTRACT FROM AUTHOR]

This work presents experimental and numerical investigations of the microwave dielectric properties of the ceramic matrix CaMoO4 (CMO) with the addition of 8, 12, and 20 wt% TiO2, obtained through the solid-state reaction method. X-ray diffraction and Rietveld's refinement revealed no evidence of secondary phases, indicating no reaction between the CMO and TiO2 phases. The dielectric properties presented an improvement with the addition of TiO2, with the CMO8 sample presenting ε r ′ = 12.8, tan δ = 7.8 × 10–4, and τf = − 6 ppm°C−1, demonstrating that this material has thermal stability (τf < 0). The ceramic was tested as a dielectric resonator antenna (DRA) and numerical simulation results showed that the materials have a realized gain of 4.40–4.92 dBi, a bandwidth of 741‒1079 MHz, and a radiation efficiency above 86%. The results indicate that CMO‒TiO2 systems could be employed in devices operating in the S-band. [ABSTRACT FROM AUTHOR]

This paper reviews the dielectric properties of Sr2TiSi2O8 (STS) ceramic in the radio frequency (RF) and microwave (MW) regions. X-ray diffraction (XRD) analysis is used to demonstrate that a small secondary phase of SrTiO3 is present in a synthesised STS ceramic. Complex impedance spectroscopy is performed, and the typical permittivity values of ceramic materials are observed. Nyquist diagrams are fitted based on an equivalent circuit using two associations of R-CPE related to the grain and the grain boundary effects. A dependence study of the changes in AC conductivity with frequency at different temperatures demonstrates that the conduction process is thermally activated, and a value of 1.0 eV is obtained for the activation energy. In the MW range, we observe values of εr = 12.7, tan δ = 1.3 × 10–2, and τf = − 6.1 ppm/°C, indicating interesting properties for applications in devices that operate in the MW region. A numerical simulation is employed to evaluate STS ceramic as a dielectric resonator antenna, and we observe a reflection coefficient of below − 10 dB, a realised gain of 4.6 dBi, a bandwidth of 475 MHz, and a radiation efficiency of around 75%. The properties of the STS matrix presented here indicate that this ceramic would be a suitable candidate for the operation of devices in the C-band, as well as in devices operating in the RF range. [ABSTRACT FROM AUTHOR]

In this work, a dual dielectric resonator antenna (DRA) oriented in opposite directions is designed and analyzed. The unique feature of the proposed antenna is to provide dual-band filtering characteristics with a quasi-isotropic radiation pattern. The upper cylindrical ceramic is fed by the combination of a conformal strip and a circular patch, while the lower one is fed by a circular aperture. The proposed feeding mechanism produces HEM11δ and HEM12δ modes inside the ceramic material at 2.8 GHz and 5.4 GHz, respectively, providing a dual-band response. The proposed radiator has two main features: (i) the arrangement of the ceramic-based radiator creates radiation nulls at 5.8 GHz, 4.8 GHz, 3.5 GHz and 2 GHz, which provides the filtering response, and (ii) the opposite orientation of the dual ceramic produces quasi-isotropic radiation features. Experimental measurements confirm its operation in the frequency ranges of 2.48–3.3 GHz and 5.21–5.48 GHz. Maximum rejection is about −20 dBi in both frequency bands, while the passband gain is about 5.0 dBi. These radiation characteristics make the proposed antenna suitable for the WLAN (2.5 GHz/5.15 GHz) frequency band. [ABSTRACT FROM AUTHOR]

A series of MCuSi4O10 (M = Ca2+, Sr2+ and Ba2+) electroceramics have been prepared by solid-state reaction and sintered at 1150 (CCSO (CaCuSi4O10)), 1100 (SCSO (SrCuSi4O10)), and 1150 °C (BCSO (BaCuSi4O10)). The structure and dielectric properties of the samples were studied by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), impedance spectroscopy at radiofrequency (RF) and dielectric resonator antenna (DRA) at microwaves. The electroceramics presented values of thermo-activated process and activation energy (Ea) between 0.65 and 1.66 eV. In addition, fitting plots showed the equivalent circuit consisting of two parallel (R/CPE) connected in series, which is associated with the grain and grain boundary electrical contributions. The microwave dielectric properties showed dielectric constant (εr) of 3.47, 5.04, and 5.40 and quality factor (Q x f) of 11,350.00, 11,438.60, and 28,983.00 GHz for CCSO, SCSO, and BCSO, respectively. All the samples have a great potential for microwave applications, especially the CCSO- and BCSO-based DRA, due to the near-zero temperature coefficient of resonant frequency (τf) values (− 2.24 and − 7.41 ppm.°C−1, respectively). The preliminary results indicate that MCuSi4O10 electroceramics are satisfactory for use as a commercial antenna for C- and X-band applications. [ABSTRACT FROM AUTHOR]

The paper presents a novel method for the enhancement in the gain and impedance bandwidth by a silicon dioxide SiO2 substrate of nano spherical dielectric resonator antenna. The results of enhanced gain and impedance are analyzed and compared with the previous research work. Nano spherical dielectric resonator antenna has been designed and simulated using HFSS software. The antenna structure contains spherical dielectric resonators at a frequency of 10.5THz with higher antenna gain and lower return loss. Simulated results show that nano spherical dielectric resonator antenna provides below 2-dB VSWR and upper 3-dB axial ratio. The VSWR is acceptable. The impedance bandwidth of nano spherical dielectric resonator antenna is 43.82%. The proposed nano spherical dielectric resonator antenna provides the gain of 6.5 dB and threturn loss of − 20.52 dB. The proposed nano spherical dielectric resonator antenna can be used in nano rectenna for energy harvesting with compact size. [ABSTRACT FROM AUTHOR]

High isolation between massive MIMO antenna elements is one of the important parameters that improves antenna performance, especially for 5G communication applications. In this study, we propose a design to improve isolation between elements to enhance the antenna performance. The proposed solution to improve the performance of massive MIMO antennas is to use a combination of dielectric resonator, electromagnetic bandgap (EBG) and defected ground structure (DGS) techniques at the frequency band 3.5 GHz as the 5G frequency band under 6 GHz. The material used is FR-4 which has a dielectric constant ( ε r ) of 4.3. Simulation results and measurements between antenna elements show an improvement in mutual coupling, widening the bandwidth and increasing the gain of the antenna. The proposed design using the dielectric resonator antenna (DRA) by MIMO 8 × 8 16 port—64 elements and the addition of EBG and DGS structures on the ground plane—has shown to suppress mutual coupling parameter lower than without using DRA-EBG-DGS design by 15 dB, increase bandwidth to 246 MHz, increase gain to 24.7 dB and improve the overall envelope correlation coefficient (ECC) parameter. [ABSTRACT FROM AUTHOR]

A graphene-based dual-band terahertz rectangular dielectric resonator antenna (DRA) is proposed in this work. The upper wall of the rectangular DRA is coated with graphene, which acts as an impedance surface to tune the resonant frequencies of the T E 111 y and T E 113 y modes of the antenna by varying its chemical potential. Also, it is observed that for some values of the chemical potential of graphene, the T E 113 y mode is not well excited. In another part of the paper, an approximate formula for obtaining the resonant frequency of the graphene-loaded DRA is presented for the first time. The resonance frequency results obtained from this theoretical method for different chemical potential values are compared with the simulation results, and it is concluded that there is a good agreement between them. [ABSTRACT FROM AUTHOR]

A dual-band frequency reconfigurable cylindrical dielectric resonator antenna (DRA) for 5G New Radio (NR) application within a Sub-6 GHz is presented in the proposed work. In this work, nine n7, n30, n38, n40, n41, n46, n47, n53 and n79 5G NR bands are presented. A novel approach for 5G NR bands has been presented to provide dual-band capabilities and frequency reconfigurability with machine learning (ML). We achieve this reconfigurability by using two PIN diode switches that operate in various configurations, allowing for a maximum wide tuning range of 80.19%. In cylindrical DRA HEM11δ\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${\text{HEM}}_{11\delta }$$\end{document} and HEM12δ\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$${\text{HEM}}_{12\delta }$$\end{document} modes are responsible for dual-band operation. The K-nearest neighbor (KNN) ML technique achieves an accuracy of more than 98%, as compared to artificial neural network (ANN), random forest (RF), extreme gradient boosting (XGB), and decision tree (DT) across all configurations for the S11\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$S_{11}$$\end{document} prediction. [ABSTRACT FROM AUTHOR]

In this letter, an alumina ceramic-based multi-input multi-output antenna is designed and examined. The proposed feeding structure provides filtering characteristics as well as creates circularly polarized waves between 2.12 and 2.35 GHz. Filtering is achieved by creating radiation null at 1.75 GHz and 2.65 GHz. The introduction of the polarization diversity concept improves the isolation level by 35 dB. Experimental testing of the fabricated antenna confirms that it works from 2.05 to 2.55 GHz. The broadside radiation pattern along with the good value of diversity makes it appropriate for wireless LAN (2.5 GHz) application. [ABSTRACT FROM AUTHOR]

This article presents a dual-band circularly polarized hybrid ring CDRA (Cylindrical dielectric resonator antenna) for wireless applications in C and X-band. A circular ring inclusive of a slotted cross-shaped microstrip feed line is used to excite the ring CDRA and generation of HEM11δ and TEM01δ modes. Multiple inverted Z-shaped apertures and circular ring along with a slotted cross-shaped microstrip feed line are responsible for the generated circular polarization wave between 3.92 and 4.08 GHz in lower band and 8.85 to 9.61 GHz in upper band with 4% (160 MHz) and 8.23% (760 MHz) axial ratio bandwidth (ARBW) respectively. The proposed antenna also offers impedance bandwidth of 20.58% (780 MHz) between 3.40 and 4.18 GHz in lower band while 29.31% (2490 MHz) between 7.25 and 9.74 GHz in upper band resonating at 3.73 and 7.79 GHz with − 26.4 and − 35.61 dB return loss respectively. The proposed ring CDRA shows stable gain of peak value 5.8 dB (simulated) and 5.8 dB (measured) in lower band while 7.7 dB (simulated) and 8.2 dB (measured) in upper band. [ABSTRACT FROM AUTHOR]

In this article, a staircase-shaped ultra-wide band dielectric resonator antenna (DRA) has been used as a sensor for the detection of breast tumor by monostatic radar-based microwave imaging (MRMWI). The proposed DRA has fractional bandwidth (BW) 98.5% and a high peak gain 5.98 dB along with dual polarization behaviour from 5.12 to 8.2 GHz and 11.02-13.8 GHz. In the MRMWI setup, DRA is placed over the breast phantom at a distance of 7 mm and provides a safe exposure of radiation (<1.6 W/Kg). For simulation, it rotates around the phantom at a fixed interval in elevation (0-180°) and azimuthal (0-360°) planes. It works as a radiate and receives the reflected signals towards and from the scanned area simultaneously. To validate the results, fabricated DRA is connected to a vector network analyzer and rotates (as done for simulation) around the artificial breast phantom. That is a replica of the human breast made from gelatin+sugar, Vaseline and wheat flour+water equivalent to skin, fat and tumor respectively. Afterward S11 responses are recorded in the presence and absence of tumor inside the phantom. A significant variation in recorded values leads to the detection of tumors that are processed further in beam-forming algorithms; delay and sum (DAS) and delay-multiply and sum (DMAS) to reform the 2-dimensional image of tumor in MATLAB. [ABSTRACT FROM AUTHOR]

Dense LiF ceramics have been successfully prepared via a cold sintering process (100 °C ≤ T ≤ 200 °C, 150 MPa ≤ P ≤ 600 MPa) and following post-annealing treatment at 800 °C. Outstanding microwave dielectric properties (εr = 8.56, Qf = 143,000 GHz, and τf = − 137 ppm/°C) are obtained in LiF ceramics cold sintered at 600 MPa/100 °C. The low sintering temperature, lightweight (2.57 g/cm3), and most importantly, the excellent microwave dielectric properties outstand the present LiF ceramics as promising candidates for millimeter-wave antenna applications. A LiF-based dielectric resonator antenna is designed and assembled for the first time. The antenna resonates at 26.65 GHz and realizes an excellent S11 of − 46.1 dB. Moreover, the measured antenna results agree well with the simulated ones, where the antenna gain and efficiency are simulated to be 5.32 dBi and 86.4%, respectively. The exceptional antenna performances verify the broad application prospects of LiF ceramics in 5G millimeter-wave systems. [ABSTRACT FROM AUTHOR]

A wideband dual-feed dielectric resonator antenna (DRA) is proposed by stacking five-layer cross dielectric resonators and dual-port coaxial feeds. The proposed DRA can realize reconfigurable polarization states among right-hand circular polarization, left-hand circular polarization and three linear polarizations at 0°, ± 45°. The impedance bandwidth of DRA is 93.6% from 6.05 to 13.4 GHz. The 3 dB axial ratio bandwidth for circular polarization states is 87.8% from 3.50–8.50 GHz and the overlapped of impedance bandwidth and axial bandwidth is from 6.05 to 8.50 GHz with gain no less than 5 dB. [ABSTRACT FROM AUTHOR]

In this paper, a compact circularly polarized asymmetric dielectric resonator antenna (DRA) excited by a quarter-wave transformer (QWT) feedline is proposed for ultra-wideband (UWB) applications. The DRA consists of two rectangular ceramic blocks with the same permittivity (εDR = 9.8) and an F-shaped metallic strip combined with the partial ground. The proposed antenna is supported first and third-order modes as T E δ 11 and T E δ 13 at 9.1 and 11.28 GHz. The proposed antenna covers ultra-wideband (UWB) range from 6.4 to 12.4 GHz (impedance bandwidth of 63.8 %) with a peak gain of 6.01 dBi at 11.5 GHz. The broad AR bandwidth of the proposed antenna is achieved by the asymmetric structure of DR and the modified ground. The simulated AR bandwidth (≤ 3 dB) of the proposed antenna is 63.8% (6.4 to 12.4 GHz), and the measured AR bandwidth is 2.5% (5.8 to 6.1 GHz) and 43.7% (6.9 to 10.9 GHz). The proposed antenna can be used for C, X band applications. [ABSTRACT FROM AUTHOR]

This article proposes the design and realization of a metasurface lens-loaded rectangular-shaped dielectric resonator antenna (DRA) operating at 4.5 GHz with enhanced gain. The MS lens, loaded above the rectangular-shaped DRA at a height of H ≈ λ0/2 from the DR block, contributes to a significantly higher gain (9.9 dBi) compared to the standalone DRA block (5.8 dBi) maintaining the overall size of the antenna as 0.90λ0 × 1.05λ0 × 0.53λ0. The proposed DRA integrated with an MS lens is systematically designed in a commercial EM solver using theoretical guidelines followed by experimental characterization of the fabricated samples. [ABSTRACT FROM AUTHOR]

This article presents a dual-band dual-polarized, slotted cylindrical dielectric resonator antenna (CDRA) for wireless applications. Multiple inverted pentagons with slotted aperture are used to radiate hybrid mode HEM11δ. The suggested radiator has two operating frequency bands: lower frequency band is from 3.75 to 3.96 GHz with 5.44% (210 MHz) fractional bandwidth resonating at 3.87 GHz while upper frequency band is from 6.58 to 8.4 GHz with 24.29% (1820 MHz) fractional bandwidth resonating at 6.63 GHz. The lower resonating band is generated because of multiple slots while upper resonating band is due to the combination of CDRA and multiple slots. The lower band is linearly polarized whereas the upper band is dual-polarized (linear/circular). Circular polarization (CP) characteristic is achieved at the upper frequency band by combining the effect of moon-type microstrip line and multiple slots. Axial ratio bandwidth (3-dB) is obtained about 7.06% (550 MHz) between 7.52 and 8.07 GHz with 0.62 dB minimum AR value at frequency 8.01 GHz. This radiator can be used in partially S and C-band applications. [ABSTRACT FROM AUTHOR]

This paper presents a patch loaded slot antenna for super wideband (SWB) application. To obtain SWB characteristic, the proposed antenna geometry combined a rectangular slot and an overlying patch excited by a trident shaped microstrip feed. It is observed that the hybrid nature of the proposed antenna effectively enhances the impedance bandwidth up to 120%, by combining the resonance of both patch and slot. Besides, it is investigated that after converting the conventional tapered feed into the trident shape feed, the impedance bandwidth is increased further from 120 to 167% ranging between 1.25 and 15 GHz. Moreover, one U-shaped slot and two L-shaped stubs are inserted into the antenna design to introduce the dual-band rejection property from 1.8 to 2.4 GHz (GSM 1800, Wi-Fi 2.1 and 2.4) and 3.1–4.2 GHz (WiMAX and C-band). Further, to validate the simulation results a prototype is practically constructed and tested. The measured result demonstrates that the designed antenna offered an impedance bandwidth of 170.3% from 1.2 to 15 GHz. Both frequency and time domain analysis ensure the suitability of the designed antenna for SWB applications. [ABSTRACT FROM AUTHOR]

This paper investigates the radiation characteristics of a Hemispherical- Dielectric Resonator Antenna (DRA) loaded with graphene strips and fed by ridge-gap waveguide (RGW) transmission line for 60 GHz. The RGW unit-cell introduces frequency bandgap from 45 to 92 GHz centered around 60 GHz. A coupling slot loaded with orthogonal oriented cross graphene strips is used to couple energy from RGW line to the hemispherical-DRA. The cross slots are used to control the type of polarization radiated from the hemispherical DRA. Different states of linear and circular polarization are achieved according to the biased/un-biased graphene strips. The hemispherical DRA introduces circular polarization bandwidth of 980 MHz with high gain of 7 dBi. Multiple-input-multiple-output (MIMO) antenna arrays consist of 1 × 2 and 2 × 2 elements are designed to enhance the total gain and circular polarization performance over the single hemispherical-DRA element. The MIMO arrays parameters such as diversity gain, transmission coefficient, multiplexing efficiency, and envelop correlation coefficient are calculated to meet the 60 GHz applications. [ABSTRACT FROM AUTHOR]

Ba5Li2W3O15 (BLWO) electroceramics with different amounts of lithium carbonate (10–15%) were synthesized using the solid-state route. Powder x-ray diffraction (PXRD) and Raman spectroscopy showed the presence of the BaWO4 (BWO) phase in the samples. The excess lithium in the BLWO matrices contributed to an increase in the BWO phase and improved the thermal stability. Images obtained by scanning electron microscopy (SEM) showed grains without a well-defined morphology and with a low porosity. The dielectric properties in the microwave (MW) range for the dielectric resonator based on BLWO were analysed by the Hakki–Coleman and Silva–Fernandes–Sombra methods. The near-zero temperature coefficient of resonant frequency (6.59 ppm°C−1) was obtained for the sample synthesized with 15% Li2CO3. Numerical studies based on the coefficient of reflection (S11) and impedance values of the BLWO-based dielectric resonator antennas (DRA) were also conducted. They agreed well with the experimental results, which indicates that this material can be applied as an antenna device in the MW range. | [ABSTRACT FROM AUTHOR]

In this paper a triple-band dielectric resonator antenna (DRA) is designed using a 0.8 mm thicker Arlan FR-25 substrate, having relative dielectric constant of 3.58 and loss tangent of 0.0035. The antenna works in three unique frequency bands of 15, 16.3 and 18.5 GHz, lying in the sub-20 GHz spectrum. A stack of ten radiating elements of AR100 material, are installed at the centre of the proposed antenna structure. The DRA is excited through an elliptical aperture in the metallic plane via a 50 Ohm microstrip feed line, etched on the rear side of the Arlan FR-25 substrate. Stacked parasitic elements are incorporated around the central radiating element for achieving enhanced gain. The proposed DRA gives satisfactory gain and fractional bandwidth of (8.06 dB, 12%), (10.7 dB, 3%) and (7.03 dB, 2.73%) at 15, 16.3 and 18.3 GHz bands, respectively. The simulation results of the DRA are compared and validated using three different analysis techniques i.e., FIT (Finite Integration Technique), FDTD (Finite Difference Time Domain) Method and FEM (Finite Element Method). The designed antenna can be used for future fifth generation (5G) systems (15 GHz), internet of things (IoT) based device-to-device (D2D) communication and satellite applications (16.3–18.3 GHz). [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

In this study, a rectenna (antenna + rectifier) performance is compared with two different types of antennas; planar and DRA. The CST Microwave Studio and Advance Design System (ADS) is used to perform co-simulation. In this, first a.S2P is generated using two similar antennas keeping at a far-field distance in CST, afterward it is imported in ADS and tested with a typical rectifier circuit. Further, two experimental methods are performed in indoor and outdoor environments to validate the simulation results. In the indoor environment, a horn antenna excited with a signal generator is used as an RF power transmitter. In contrast, in the outdoor environment, the horn antenna is replaced with an ambient power source like a mobile base station. In both methods, at receiving side rectenna (antenna + rectifier) is kept in the far-field region. Here, both planar metallic and dielectric resonator antennas are use done after another with the rectifier circuit to test the rectenna system. From the simulation and experiments performed in indoor and outdoor environment method, it is confirmed that the rectenna system tenders the best performance with dielectric resonator antenna. [ABSTRACT FROM AUTHOR]

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 (ε 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. [ABSTRACT FROM AUTHOR]