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For 5G sub-6 GHz outdoor applications, a highly isolated two-port rectangular dielectric resonator antenna (RDRA) with UWB MIMO is presented in this research. For isolation enhancement purposes at the lower frequency band (2.27 GHz-2.62 GHz), a longitudinal slot is inserted at the ground plane. For isolation enhancement at the higher frequency band (3.9 GHz-5.73 GHz), an edged hole is inserted in the RDRA. Investigations are conducted on the impacts of slotted ground as well as edged hole radius on isolation. The orthogonal feeding scheme of UWBMIMO RDRA considering both edged hole and slotted ground plane effects are investigated. For the edged hole MIMO RDRA with a slotted ground plane, isolation is better than -24.7 dB at a higher frequency band and is better than -15.5 dB at a lower frequency band. This isolation improvement is explained by the surface current density distribution. The use of an edged hole RDRA and an aperture-coupled orthogonal feeding allows UWB bandwidth and good efficiency performances on the 5G operating bands. To justify the MIMO performance, the envelope correlation coefficient (ECC) and diversity gain (DG) are applied. [ABSTRACT FROM AUTHOR]

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 342◦ and 1.8 dB reflection loss. The computed results are compared with experimental results revealing reasonable agreement, thereby confirming the viability of the design. [ABSTRACT FROM AUTHOR]

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

This paper presents miniature dual-band cylindrical dielectric resonator antenna (CDRA) based on button antenna for wireless body area network (WBAN) applications. A button antenna is designed by stacking two CDRAs (low and high permittivity) fed by coaxial probe through the ground plane and penetrates the bottom CDRA. The prime contributions of using DRAs are to enhance the performance and to provide a compact size of antenna. However, the coaxial probe realizes two radiation patterns, monopole and broadside patterns. A comprehensive validation using CST microwave studio is carried out to determine the characteristics of the proposed button antenna. In addition, to ensure that the results are acceptable to the practitioner in this field, a prototype was fabricated and tested. The superiority of the proposed antenna is confirmed by possessing 39% more compact size compared to previously reported studies, efficiency of more than 63% and bandwidth of 4.9% and 6.6% for lower and upper band, respectively. This proposed design is a promising candidate to benefit on/off body communication devices operating at 2.4 and 5.6 GHz. [ABSTRACT FROM AUTHOR]

In this paper, a new approach to create frequency band rejection is applied to a wideband Hshaped dielectric resonator antenna (DRA). In order to create a notch characteristic in the operating band of the TEy1δ1 and TEy2δ1 modes, and guided by their theoretical and simulated electric field distributions, a narrow conductive strip is incorporated around the mid-section of the H-shaped DRA. The orientation of the notching strip is determined based on the electric field distribution of the selected modes for the frequency rejection. Furthermore, the selected feeding method improves the radiation patterns for this DRA shape compared to its previous designs. The new design offers an operating frequency range that extends from 4.15 to 9.8 GHz, allowing 81% of fractional bandwidth. The first notch is created at 6.5 GHz, while the second one is at 8 GHz. Average radiation efficiency of 95% across the frequency of interest is achieved with overall dimensions of 40×30×11.4 mm3. The proposed design is simulated using Ansys HFSS and validated by measurement. [ABSTRACT FROM AUTHOR]

In this work a novel miniaturized frequency reconfigurable Dielectric Resonator antenna using Artificial Magnetic Conductor (AMC) surface is proposed. The prototype is set to work for 5G mid-band frequencies and Wireless Body Area Network (WBAN) applications. The work consists of two parts: firstly, the miniaturization of the prototype using AMC surface and secondly using the same AMC surface to reconfigure the frequency to another wireless application. Using AMC surface, the DR volume is reduced by 85% percent. Connecting the AMC unit cells through ideal switches (micro-trip slabs) re-configures the DR for different frequency. The overall performance observed before switching as well as after switching in both the cases is promising. The design is fabricated for performance analysis. A close agreement is reported between simulated and measured values of the reflection coefficients, radiation pattern, gain and efficiencies. The prototype has stable radiation pattern for both the operating frequencies. The impedance bandwidth values for both the resonance frequencies are 14.2% and 16% respectively. The prototype has a maximum gain of 6.8dBi and a maximum efficiency of 88%. [ABSTRACT FROM AUTHOR]

In this paper, a new wideband and compact three-segment composite dielectric ring resonator (DRR) antenna excited by an axi-symmetric coaxial monopole has been introduced. The proposed antenna has been investigated numerically and experimentally for enhanced impedance bandwidth. At the lowest operating frequency, the presented antenna has a footprint area of just 0.16 x 0.16. According to the measurement results, the antenna offers a fractional impedance bandwidth equal to 159% with 8dBi peak gain. The antenna provides symmetrical and stable monopole like radiation pattern over the entire impedance bandwidth. With such performance, the suggested antenna can be usefully employed in different wideband applications such as electromagnetic interference (EMI) and defense applications. [ABSTRACT FROM AUTHOR]

With the increase in wireless services, the demand for antennas that can operate at more than one frequency has increased. This work proposes a slot antenna whose frequency of operation can be configured into three bands of 2.4 GHz, 5 GHz, and 3.5 GHz for the Wireless-Area-Network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) applications. The switching between the three bands is achieved by two PIN diodes properly placed between the two sides of the slot. The antenna consists of a rectangular slot etched on the ground plane, while on the other side of the substrate, there is a microstrip line to feed the slot with an open stub for matching. The tri-band frequency reconfigurable slot antenna has been studied, and its parameters optimized using computer simulation Technology (CST-MWS). Parametric study on the slot dimensions and the microstrip feeding is presented. For verification of the simulation results, the antenna is fabricated and measured. The simulated and measured parameters such as return loss, radiation pattern, and gain show excellent agreement for the three operation bands. [ABSTRACT FROM AUTHOR]

This paper presents a resonator based decoupling structure for 2×2 dual polarized array antenna. The designed structure consists of two decoupling resonators placed between the antenna elements. The proposed decoupling structure can effectively enhance the isolation and has negligible impact on the radiation patterns. [ABSTRACT FROM AUTHOR]

A high power dielectric reflectarray with a continuous variation of the effective permittivity of a dielectric slab is proposed, based on a cross-shaped element implemented in the slab. The improved method used to retrieve the effective permittivity from the S parameters shows that a continuously changing effective relative permittivity from 1.25 to 3.4 can be reached by adjusting the notch width of the cross-shape, yielding a full 360° range of phase shifts at 9.3GHz. An array of 10×10 elements is designed to verify the radiation properties. Simulation results show that a main beam direction of 25° and a maximum gain of 19.5dB can be realized at the 9.3GHz center frequency. The power capacity of the element reaches 371kW, opening the possibility of high power applications. Fused Deposition Modelling (FDM), a specific approach in 3D printing, was employed for the fabrication of a prototype. This technology significantly reduces material cost and manufacturing time. [ABSTRACT FROM AUTHOR]

A compact, ultra light weight and efficient asymmetric circular slit circularly polarized patch antenna is proposed for vehicular satellite communications. The circular slit in the corners of the patch is utilized for achieving circular polarization and an edge-fed through a microstrip feed line incorporates a quarter-wave transformer for impedance matching. Simulation results indicate an improvement in cross polarization isolation. The proposed antenna is fabricated using RT/DUROID 5880 material which is lighter, flexible and less expensive compared to the commercially existing ceramic corner curtailed patch antennas. The measured results indicate a reflection coefficient of -24.1 dB at resonant frequency, impedance bandwidth of 490 MHz ranging from 11.03 GHz to 11.52 GHz, axial ratio bandwidth of 180 MHz ranging from 11.16 GHz to 11.34 GHz and constant gain through the operating bandwidth with an apprehended peak gain of 5.6 dB. Experimentations affirmed that measured radiation results of the suggested antenna are similar to the simulation results and can be utilized as vehicle roof mounted antennas for diverse satellite communication applications. [ABSTRACT FROM AUTHOR]

A compact design of non-uniform meta-surface for patch antenna main beam steering is presented in this paper. The proposed design is realized using printed circuit board technology. By adding the non-uniform meta-surface to a patch antenna, the main-beam direction of the patch antenna can be steered by an angle up to 30° from the boresight direction. The meta-surface together with the patch antenna here is called meta-surfaced antenna, which has a very compact structure since there is no air gap between the meta-surface and the patch antenna. The meta-surfaced antenna is studied and designed to operate around 2.45GHz. To verify the results of simulation, the meta-surfaced antenna is fabricated and measured. Measured results show that the antenna has an operating bandwidth from 2.35-2.5GHz and peak realized gain of 7.1dBi. [ABSTRACT FROM AUTHOR]

This paper presents a Dielectric Resonator based dual frequency band Multiple Input and Multiple Output (MIMO) antenna for wireless communication. This antenna is designed for WLAN (5.5-5.8 GHz) and X-band (8-8.1 GHz) applications. A pair of DRAs is placed on a FR-4 substrate and is excited through microstrip feed lines placed on rear side of substrate. A via-less EBG structure is introduced to suppress the mutual coupling among DRAs. The measured isolation among the two antenna ports is 25 dB and 41 dB for 5.6 GHz and 8.05 GHz respectively. The overall dimension of the antenna is 0.72 λo × 0.52 λo at lower resonant frequency. Simulated and measured results are in good agreement, which supports the potential application of the proposed antenna for high gain WLAN and X-band applications. [ABSTRACT FROM AUTHOR]

A square dielectric resonator element (SDR) with a defected ground structure (DGS) is investigated. The proposed DGS is composed of two rectangular slots connected by two transverse slots and is placed in the ground plane. It is fed by a strip line through the substrate layer. The objective of this structure is to design dielectric resonator band-stop filter (DRF) and enhance the performance in terms of better insertion loss and increased bandwidth. The DRF has been fabricated and some measurements are taken. The cutoff frequency of the band-stop filter is 2.25 GHz, with transmission loss of 2-dB. The 3-dB of the band-stop filter is 1.24 GHz. The effect of the transverse slot width on the filter response curve is studied. The same structure is modulated to be frequency reconfigurable DRF to achieve frequency agility by using ideal metallic switches. The cut-off frequency is moved to 1GHz, and the 3-dB bandwidth in 1.5 GHz, while the transmission loss is decreased by 0.75 dB. Finally, the effect of loading SDR with metal plate is investigated. This structure combines the dielectric resonator antenna (DRA) and the DRF to propose dielectric resonator antenna filter (DRAF), this structure is used to miniaturize the global-positioning-system receivers that contain both the antenna and filter. The DRAF has been fabricated and measured, it has 3-dB pass bandwidth in 1GHz. Factors such as return loss, insertion loss, radiation pattern and mutual coupling of DRAF are calculated using finite element method (FEM). Comparison of calculation and measurement factors of DRAF shows a good agreement. [ABSTRACT FROM AUTHOR]

A compact wide band and low profile circularly polarized antenna is presented based on stepped open-ended slotline in this paper. The antenna is composed of four open-end-slotted patchs and a feed network. Four open-end-slotted patchs are sequentially rotated and vertically soldered on the ground plane of the feed network, and are excited by a wide band transition from strip-line to slot-line with short pin in antenna element. The CP radiation of the proposed antenna is realized by four output ports of the feed network which transmit four signals that have equal amplitude with quadrature phase difference (00, 900, 1800, and 2700). Simulation results are compared with the measurements, and a good agreement is obtained. The measured results show that the proposed antenna can provide broad impedance bandwidth of 73.4% (3.5 GHz-7.56 GHz) (reflection coefficient less than -10 dB), a maximum gain of 4.74 dBi, and a 3-dB axial ratio (AR) bandwidth of about 35.1% (3.65 GHz-5.2 GHz). [ABSTRACT FROM AUTHOR]

In this paper, a wideband Fabry-Perot (FP) resonator antenna is designed based on single-layer frequency selective surface (FSS) structure. The antenna adopts a single-layer complementary circular FSS structure as the partially reflecting surface (PRS) of Fabry-Perot resonator antenna to improve the gain. The wideband slot-coupled patch antenna is used as the source. The proposed FSS maintains a positive slope reflection phase gradient in the band of 10.3-16.0 GHz, which satisfies the realization conditions of the wideband Fabry-Perot resonator antenna. The measured results show that the 10-dB impedance matching bandwidth of the proposed Fabry-Perot resonator antenna covers 11.99-15.54 GHz (25.8%), the maximum gain is 13.16 dBi at 14.2 GHz, and the 3-dB gain bandwidth is 26.1%. The measurement results verify the feasibility of the design method. [ABSTRACT FROM AUTHOR]

A compact, flexible antenna for wireless applications, i.e., WLAN/WiMAX/Wi-Fi, UMTS2100, C-Band, and DSRC is presented. The quad-band antenna is designed and analyzed in terms of efficiency, gain, radiation pattern, return loss, and VSWR. The optimized design consists of a CPW fed rectangular ring patch with the semi-circular ground. The cross-lines and the semicircular ground is investigated to ascertain the multiband effect. A concept of inset feed mechanism is also interpolated to enhance impedance matching. The framed antenna is examined under the bent condition as well. The reported work is an apt candidate for the proposed applications because of its high efficiency of 95% with a peak gain of 3.22 dBi along with VSWR less than 2. With stable radiation pattern and bandwidth, there is a justified concurrence between simulated and measured results. [ABSTRACT FROM AUTHOR]

A dielectric resonator antenna is designed for WLAN 5.5 GHz band applications in this study. The dielectric resonator antenna is fabricated on a cheap FR4 substrate with grounded CPW (GCPW) structure. A new closed circular loop GCPW slot structure is employed to obtain wideband impedance matching. Results of the designed dielectric resonator antenna show that good agreement between simulated and measured reflection coefficients, radiations, and antenna gains is observed. The measured -10 dB bandwidth of the dielectric resonator antenna is 1.6 GHz (28.5%, 4.8 - 6.4 GHz), which covers the WLAN 5.5 GHz band. [ABSTRACT FROM AUTHOR]

In this paper, two, four, eight and sixteenelement Rectangular Dielectric Resonator Antenna (RDRA) linear arrays fed by microstrip line have been designed and simulated. The DRA is excited by a vertical strip placed on the middle of the DRA wide side wall through a coaxial probe attached to the microstrip line on the other side of the substrate. The ground plane is sitting directly underneath the RDRA while the microstrip line feeder is at the opposite side of the substrate to avoid the unwanted radiation from the feeder. The simulated and measured 10 dB return loss bandwidth of the antenna arrays are 67.8%, 75%, 73.5%, and 76% for the two, four, eight and sixteen-element arrays respectively. The simulated gain of the single element antenna is about 6 dBi, while it reaches to about 17 dBi for the 16-element array. [ABSTRACT FROM AUTHOR]

Based on the concept of perturbation theory, a modification to the dielectric waveguide model (DWM) is presented for the calculation of resonant frequency of rectangular dielectric resonator antenna (DRA). A large number of simulations are performed using commercial software and the results are compared between those of the DWM and the proposed method. Finally, the accuracy of proposed method is validated by the experimental data available in the literature. Differences between the measured and theoretical resonant frequencies vary by less than 2%. [ABSTRACT FROM AUTHOR]

A wideband two element rectangular dielectric resonator antenna (DRA) is proposed in this paper. Each DRA element has two excitation strips and four parasitic patches. A wide impedance bandwidth of more than 37% at the center frequency of 1.6 GHz is achieved. The antenna radiation beam can be switched between two positions in elevation plane, i.e., ? = 45° and ? = -45°. The measured antenna gain is found to be more than 6 dB in the whole frequency band of operation. The matching and the radiation characteristics of the designed switched beam antenna are studied and validated by measurements. A very good agreement between the measured and simulated results is observed. [ABSTRACT FROM AUTHOR]

Nano-antennas have been introduced with wide bandwidth for faster data communications. The material properties of good conducting metals introduce plasmonic behavior at THz frequencies. The material property of good conducting metals using the Durde Lorentz model have been investigated. The radiation characteristics of nano-dielectric resonator antenna NDRA reflectarray at 633 nm have been investigated. A parametric study for the NDRA unit-cell dimensions and material has been introduced. Different types of metals are used as a supporting plane of the NDRA unit-cell. A NDRA with silver, copper, and aluminum supporting plane have been designed and analyzed for reflectarray antennas. A nano-reflectarray unit-cells with supporting plane having different metals have been introduced. Comparisons between the radiation characteristics of reflectarrays with different supporting plane metals have been illustrated. A compromise between the size, maximum gain, and operating bandwidth of the nanoreflectarray is investigated for terahertz applications. The finite integral technique is used to carry a full wave analysis to design a NDRA reflectarray. [ABSTRACT FROM AUTHOR]

A new simple compact ultra-wideband (UWB) dielectric resonator antenna (DRA) is presented. The finite-difference time-domain (FDTD) method is used to the full-wave analysis of this structure. The antenna consists of a modified stepped microstrip fed monopole printed antenna loaded with a rectangular dielectric resonator, truncated ground plane and a parasitic strip underneath the dielectric resonator (DR). By using an optimized truncated ground plane and a combination of stepped feed line with dielectric resonator, an ultra-wide impedance bandwidth of 153% for (S11 ≤ -10 dB), covering the frequency range of (3.7-28 GHz) is achieved. The added parasitic strip can improve the radiation pattern, especially at high frequencies. The proposed antenna covers almost the entire UWB (3.1-10.6 GHz), Ku (12.4-18 GHz) and K (18-26.6 GHz) frequency bands. Also, this antenna has an omnidirectional and stable radiation pattern over the whole operating frequency range and a compact size of 15×20×5.8 mm³) that make it suitable for wideband wireless system applications. This structure is light weight and can be easily fabricated. A prototype is built and measured. The simulated and measured results are in good agreement with the computed FDTD result. [ABSTRACT FROM AUTHOR]

This paper demonstrates a shape synthesis technique for multi-mode dielectric resonator antennas using binary genetic algorithm and characteristic mode analysis. The cost function for the synthesis process is defined from characteristic modal parameters, such as modal quality factors and self-resonance frequencies. Since only modal parameters are involved in the cost function, the shape synthesis process is made independent of feeds. In the paper, we demonstrate the shape synthesis of a DRA with three self-resonant modes at 3 GHz. [ABSTRACT FROM AUTHOR]

The modeling and validation of a 33 GHz shaped dielectric antenna design is investigated. The electromagnetic modeling was performed in both WIPL-D and FEKO, and was used to validate the antenna design prior to fabrication of the lens. It is shown that both WIPL-D and FEKO yield similarly accurate results as compared to measured far-field gain radiation patterns. [ABSTRACT FROM AUTHOR]