Showing papers on "Dielectric resonator antenna published in 2018"
TL;DR: In this paper, a wideband omnidirectional dielectric resonator antenna (DRA) with filtering response is investigated, where the DRA is placed on a circular patch and excited by a hybrid feed that consists of a probe and a metallic disk.
Abstract: A wideband omnidirectional dielectric resonator antenna (DRA) with filtering response is investigated. The DRA is placed on a circular patch and excited by a hybrid feed that consists of a probe and a metallic disk. Two omnidirectional DR modes (TM $_{01\delta }$ and TM013 modes) along with a patch mode and a probe mode are simultaneously excited by the hybrid feed, providing a broad bandwidth of 52.8%. The feeding scheme also establishes a cross-coupled structure in the DRA, which introduces a radiation null at the upper edge of the passband. A ring slot and four shorting pins are loaded on the patch to provide another radiation null at the lower edge of the passband. Consequently, a compact wideband filtering DRA (FDRA) with quasi-elliptic bandpass response is obtained without requiring specific filtering circuits. This wideband design is also modified to realize a dual-band FDRA. The metallic disk of the hybrid feed is moved to touch the upper DR face of the cylindrical hole. It divides the wide passband into two separate bands, giving a flat stopband between them. Four additional rectangular ring slots and shorting pins are fabricated on the ground plane to further widen the bandwidth and improve the filtering performance of the second band. As a result, a dual-band FDRA with the bandwidths of 10.1% and 3.73% is achieved. In each design, both the measured and simulated out-of-band suppression levels are about 15 dB.
87 citations
TL;DR: In this paper, a differential dual-polarized filtering dielectric resonator antenna (DRA) is proposed to achieve high isolation for input ports, and the elaborately designed feeding strips ensure controllable input impedances for integration applications.
Abstract: This communication presents a differential dual-polarized filtering dielectric resonator antenna (DRA). In this antenna, a four-leaf-clover-shaped dielectric resonator is excited with two groups of out-of-phase modes. The novel configuration and differential feeding provide the DRA with high isolation for input ports, and the elaborately designed feeding strips ensure controllable input impedances for integration applications. After integrating with a pair of filtering baluns on the opposite side of the reflecting ground, the proposed DRA also exhibits good out-of-band rejection for each port with a wide stopband and two radiation nulls at band edges. A prototype has been designed and implemented, and reasonable agreement between the measured and simulated results can be observed.
80 citations
TL;DR: In this article, a broadband polarization-reconfigurable Fabry-Perot (FP) resonator antenna is presented for WLAN/WiMAX applications, which achieves a broadband 3dB gain bandwidth by designing the PRS layer to have a reflection phase with positive slope over as wide a frequency band as possible.
Abstract: In this letter, a broadband polarization-reconfigurable Fabry–Perot (FP) resonator antenna is presented for WLAN/WiMAX applications. The open air-filled FP cavity is constructed by a partially reflective surface (PRS) layer directly placed over a fully reflective ground plane. A two-element patch array is employed to serve as a feeder. To achieve polarization reconfigurability, the feeding antenna is designed to have the capability of switching between horizontal linear polarization (HP) and vertical linear polarization (VP) by controlling the on/off states of four pairs of p-i-n diodes. By combining the frequency resonances of the FP cavity and the feeding antenna, the proposed FP resonator antenna obtains broadband performance. Furthermore, the proposed antenna achieves a broadband 3 dB gain bandwidth by designing the PRS layer to have a reflection phase with positive slope over as wide a frequency band as possible. The proposed antenna was fabricated and experimentally characterized. Measurements demonstrate that it achieves a −10 dB impedance bandwidth of 21 $\%$ ranging from 2.2 to 2.72 GHz, which can well cover WLAN/WiMAX band of operation. The 3 dB gain bandwidths of 12.5 $\%$ and 14.6 $\%$ are obtained with peak realized gains of 15.1 and 14.8 dBi for the HP and VP, respectively.
79 citations
TL;DR: In this paper, a multiband dielectric resonator (DR) antenna with dual-band circularly polarized (CP) response is proposed, which achieves a measured 3 dB axial ratio (AR) bandwidth of 19.98% in lower band and 3.07% in upper band.
Abstract: A multiband dielectric resonator (DR) antenna is proposed with dual-band circularly polarized (CP) response. This antenna consists of an inverted-sigmoid shaped DR. A metallic strip is applied at the surface of the DR to achieve the circular polarization. The fundamental and higher order hybrid modes are excited in the antenna structure because of the specific geometry. The antenna with dual-band CP response provides the measured 3 dB axial ratio (AR) bandwidth of 19.98% in the lower band and 3.07% in the upper band. The upper band 3 dB AR response can be tuned in different 10 dB impedance passbands of the antenna by changing the location and width of the metallic strip. Antenna response can also be tuned to obtain the triple band CP operation.
60 citations
TL;DR: In this paper, a singly-fed wideband circularly polarized (CP) dielectric resonator (DRA) antenna with four sequentially rotated metallic plates is investigated, where the square DRA is excited by a microstrip-coupled cross-slot to generate CP fields.
Abstract: A singly fed wideband circularly polarized (CP) dielectric resonator (DR) antenna (DRA) with four sequentially rotated metallic plates is investigated. The square DRA is excited by a microstrip-coupled cross-slot to generate CP fields. By introducing four vertical metallic plates around the DR, three adjacent axial-ratio (AR) passbands are generated due to the cross-slot-fed DRA, the rotated metallic plates, and the interaction between the DR and metallic plates, leading to a very wide AR bandwidth. A prototype has been fabricated and measured to validate the design. Measured results show that the proposed CP DRA has a −10 dB impedance bandwidth of 46.9%, a 3 dB AR bandwidth of 49.5%, and an average gain of 4.7 dBic within the passband.
58 citations
TL;DR: In this article, a two-layer higher-order-mode circularly polarized (CP) rectangular dielectric resonator antenna (DRA) is proposed at a frequency range of 10-13 GHz using a single feed.
Abstract: A two-layer higher-order-mode circularly polarized (CP) rectangular dielectric resonator antenna (DRA) is proposed at a frequency range of 10–13 GHz using a single feed. The configuration incorporates the DRA and a dielectric coat layer with respective dielectric constants of 10 and 3.5. Utilizing the outer layer offers a number of advantages such as a wider impedance and the CP bandwidths of ∼21% and 9.5%, respectively, as well as a high gain of ∼11 dBic. A close agreement has been achieved between the experimental and simulated results.
52 citations
TL;DR: In this paper, a hemispherical dielectric resonator antenna (DRA) generating two orbital angular momentum (OAM) states of l 1 + 1 and l 2 − 1 was studied theoretically and experimentally.
Abstract: A hemispherical dielectric resonator antenna (DRA) generating two orbital angular momentum (OAM) states of l = +1 and −1 is studied theoretically and experimentally. The DRA is fed with two orthogonal signals, exciting two degenerate higher-order TE221 modes that generate the two OAM states. It was simulated with full-wave simulation software to verify the design method. A prototype operating in the microwave band (5.8 GHz) was fabricated and measured. Its S-parameters, intensity profile, and phase pattern are simulated, and the results are compared with measurements. Also, its far-field radiation pattern, realized antenna gain, and total antenna efficiency are shown for a complete study of the antenna.
51 citations
TL;DR: In this article, the cylindrical dielectric resonator antenna (DRA) is applied to the first omnidirectional circularly polarized (CP) diversity DRA, and the measured and simulation results are in reasonable agreement.
Abstract: The cylindrical dielectric resonator (DR) antenna (DRA) is excited in its omnidirectional TM $_{01\delta }$ mode by a planar shorted microstrip cross. With this nonintrusive feed, the DRA can be fabricated without the need of drilling a hole in the DR as required in the probe feed method. This DRA is applied to the first omnidirectional circularly polarized (CP) diversity DRA. To generate omnidirectional CP fields, the TM $_{01\delta }$ and TE $_{011+\delta }$ modes are excited simultaneously. The TE $_{011+\delta }$ mode is excited by four microstrip arcs. They provide a pair of equivalent magnetic dipoles that generate fields that are orthogonal to those of the TM $_{01\delta }$ mode. Omnidirectional CP fields can be obtained when the (orthogonal) fields of the TM $_{01\delta }$ and TE $_{011+\delta }$ modes are equal in amplitude but in phase quadrature. In our two-port CP diversity design, phase differences of +90° and −90° are obtained in ports 1 and 2 to generate right- and left-hand CP fields, respectively. Prototypes at ~2.4 GHz were designed, fabricated, and measured for WLAN applications. The S-parameters, radiation patterns, antenna gains, and efficiencies are studied. For the diversity design, the axial ratio, envelope correlation coefficient, and mean effective gain are also obtained. The measured and simulation results are in reasonable agreement.
48 citations
TL;DR: The experimental results confirm that the proposed RDRA is operated over two frequency bands, i.e., 3.4–3.58 GHz and 5.1–5.9 GHz.
Abstract: This paper examines a dual-band circularly polarized (CP) Rectangular Dielectric Resonator Antenna (RDRA). The RDRA is excited by using triangular ring-shaped aperture and an additional parasitic strip, which is connected to the one side of the RDRA. Three striking features of the proposed design are: (i) modified feeding structure (triangular ring-shaped aperture along with microstrip line) and parasitic strip create dual-radiating modes in the RDRA (i.e. ${\mathrm {TE}}_{1,\delta ,1}^{\mathrm {y}}$ and ${\mathrm {TE}}_{\mathrm {1,4,1}}^{\mathrm {y}}$ ); (ii) modified feeding structure with parasitic strip generates CP wave in both the frequency bands; and (iii) The left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP) of proposed antenna can be controlled by taking the mirror image of triangular ring-shaped aperture and parasitic strip. Simulated outcomes have been practically confirmed with the help of developed prototype of the proposed antenna. Measured and simulated results show high harmony to each other. The experimental results confirm that the proposed RDRA is operated over two frequency bands, i.e., 3.4–3.58 GHz and 5.1–5.9 GHz. The 3-dB axial ratio bandwidth of the proposed antenna is about 3.46–3.54 GHz (LHCP) and 5.18–5.34 GHz (RHCP) in lower and upper frequency band, respectively. The proposed antenna is fairly applicable for worldwide interoperability for microwave access and wireless local area network applications.
39 citations
39 citations
TL;DR: In this article, a dual-function cylindrical dielectric resonator (DR) was used as the load of a broadband phase delay line (PDL) and as a DR antenna (DRA) for the first time.
Abstract: Dualfunction cylindrical dielectric resonator (DR) used as the load of a broadband phase delay line (PDL) and as a DR antenna (DRA) is presented for the first time. In the broadband PDL design, the cylindrical DR is used as the load to improve impedance match and phase shift. At the same time, the delay line is used to feed the same DR for the antenna part. By designing 90° and 180° PDLs, circularly polarized (CP) and differential DRAs can be obtained, respectively. As compared with those using a hybrid coupler, the new CP and differential DRAs can be made much more compact. Also, the external $50~\Omega $ load required by the hybrid coupler can now be avoided. For demonstration, two CP and differential cylindrical DRAs for 2.4 GHz WLAN applications are designed, fabricated, and tested. Good agreement between the measured and simulated results is observed. The CP design has an overlapping axial ratio and impedance passband of 24.2%. For the differential design, a broadside radiation mode with very low cross-polarization level is obtained.
TL;DR: In this article, a 270 GHz × 9 multiplier chain with on-chip dielectric-resonator antenna (DRA) developed in a commercial 0.1-μ m GaAs pseudomorphic high electron-mobility transistor technology with cutoff frequencies of 130/180 GHz was presented.
Abstract: This paper presents a 270 GHz × 9 multiplier chain with on-chip dielectric-resonator antenna (DRA) developed in a commercial 0.1- μ m GaAs pseudomorphic high electron-mobility transistor technology with cutoff frequencies $f_{{\rm{T}}}\, / f_{{\rm{MAX}}}$ of 130/180 GHz. The multiplier integrates a W-band tripler followed by a driver amplifier, a J-band tripler, and an on-chip antenna. The multiplier breakout achieves a measured peak output power of –4 dBm at 270 GHz and a 3-dB bandwidth of 40 GHz (from 255 to 295 GHz). By introducing the high-pass matching network into the multiplier design, the in-band unwanted harmonic suppression is improved to be over 40 dBc within the entire bandwidth. The higher order mode (TE δ 13 mode) dielectric resonator is introduced in the on-chip antenna design to enhance the antenna gain and bandwidth without additional chip area consumption. The multiplier chain with the on-chip DRA has a measured EIRP of +2 dBm at 270 GHz and a 3-dB bandwidth of 33 GHz (from 258 to 291 GHz). Compared with other J-band multipliers, this paper achieves the best spurious suppression and comparable output power while using the technology with the lowest cutoff frequencies.
TL;DR: In this paper, a dielectric resonator-based multiple input multiple output (MIMO) antenna system with dual-band characteristics is presented, where a modified annular ring printed line acts as a magnetic dipole and creates two different radiating modes.
Abstract: In this research article, a dielectric resonator-based multiple input multiple output (MIMO) antenna system is presented with dual band characteristics. The proposed MIMO antenna includes two symmetrical hybrid radiators. Each hybrid radiator consists of a modified annular ring printed line along with a cylindrical dielectric resonator antenna (CDRA). A modified annular ring printed line acts as a magnetic dipole and creates two different radiating modes (HEM
11δ
and TE
01δ
) in the dielectric resonator. The approach of the hybrid antenna (combination of the modified annular ring printed line and CDRA) is taken into account for achieving dual band characteristics. Orthogonally placed antenna elements and a narrow slit in the ground plane are used to improve isolation (|
S
12
| <; -20 dB) in the entire operating frequency range. The antenna prototype is fabricated and measured for validating the simulated results. The proposed MIMO radiator is operating over two frequency bands, i.e. 1.75-2.4 and 3.5-5.5 GHz. Different MIMO diversity performance parameters (envelope correlation coefficient, diversity gain, mean effective gain, total active reflection coefficient, and channel capacity loss) are also inspected and found within acceptable limits.
TL;DR: In this article, the modeling, design, and optimization of a new substrate integrated waveguide middle-fed series rectangular dielectric resonator antenna array with 45° linear polarization is presented.
Abstract: The modeling, design, and optimization of a new substrate integrated waveguide middle-fed series rectangular dielectric resonator antenna array with 45° linear polarization are presented. The implicit space mapping technique is applied for the optimization of the antenna array. A tunable circuit model is built, which serves as the coarse/surrogate mode, and a full-wave solver is used as the fine model. High design and optimization efficiency is demonstrated using an eight-element array. The reflection coefficient of the array antenna is optimized with only two iterations. The experimental data for the eight elements antenna array, operating at the millimeter-wave band (34–36 GHz), are used for the validation of both performance of the design and modeling techniques. The measured radiation pattern demonstrates a broadside beam with a maximum radiated gain of 13.55 dB over an operating impedance bandwidth of 2.2 GHz.
TL;DR: In this paper, a dual-plane beam-sweeping dielectric resonator antenna (DRA) using cantilever enabled frequency selective surfaces (FSSs) is presented.
Abstract: In this letter, a dual-plane beam-sweeping dielectric resonator antenna (DRA) using cantilever enabled frequency selective surfaces (FSSs) is presented. The proposed antenna consists of a conventional cylindrical DRA and a hexagonally arranged active FSS operating at 30 GHz frequency band. Initially, the reconfigurable FSS using cantilever beams is designed and analyzed. Furthermore, a prototype of the proposed antenna with FSS is designed, fabricated, and measured. The beam sweeping is obtained in both azimuth and elevation planes of the antenna. The whole azimuth plane is covered by the switched beams in six steps of an angle of 60 $^\circ$ . In the elevation plane, two steps of angles are obtained at 90 $^\circ$ and 30 $^\circ$ . The measured antenna gain of 8.1 dB is obtained.
TL;DR: A novel technique to design a broadband circularly polarized dielectric resonator antenna (DRA) with a lattice structure is proposed for the first time and its reconfigurable version, which can operate in left-handed circular polarization, right-handed CP, and linear polarization states, has been further presented.
Abstract: In this paper, a novel technique to design a broadband circularly polarized dielectric resonator antenna (DRA) with a lattice structure is proposed for the first time. Two resonant modes of TE 111 and TE 211 can be simultaneously excited through a cross-slot to constitute a wide operating bandwidth. On this basis, its reconfigurable version, which can operate in left-handed circular polarization (CP), right-handed CP, and linear polarization (LP) states, has been further presented. The latter possesses a simple design procedure to implement the reconfigurability since all the reconfigurable feeding circuits are isolated from the radiating DRA by the ground plane and only five p-i-n diodes are needed. Besides, a Teflon-based template is adopted to solve the problem of dielectric blocks’ critical placement and alignment tolerances. A backed cavity based on substrate integrated waveguide technology is introduced to reduce the unwanted radiation from the surface wave. Measured results indicate that the reconfigurable prototype can achieve a 3-dB axial ratio bandwidth of 20.7% for CP states, an impedance bandwidth of 29.6% for LP state with a cross-polarization level of better than −20 dB, and a peak gain over 7.3 dBi for all states. The proposed antenna can be used for polarization diversity applications of the modern wireless system.
TL;DR: In this article, a new kind of technique to generate broadside circular polarization (CP) in a dielectric resonator antenna has been presented, where the geometrical shape of a simple cylindrical dielectrical resonator has been deformed periodically with same angular factor (β = 45°) along the azimuthal direction.
Abstract: A new kind of technique to generate broadside circular polarization (CP) in a dielectric resonator antenna has been presented in this letter. In the proposed CP design, the geometrical shape of a simple cylindrical dielectric resonator has been deformed periodically with same angular factor (“β” = 45°) along the azimuthal direction. Assuming magnetic boundary conditions at the air-dielectric interface, the tangential electric fields are decomposed orthogonally in such a way that circularly polarized wave could be generated. To validate the antenna performance, an antenna prototype has been fabricated and experimentally verified where 51.2% (3.37–5.69 GHz) of input impedance bandwidth (| $S_{11}$ | AR ≤ 3 dB) have been obtained.
TL;DR: In this article, the axial ratio (AR) bandwidth of a circularly polarized dielectric resonator antenna with a single feeding was enhanced by inserting the notches and conductive coating in the resonator.
Abstract: Abstract This paper presents a new technique for the enhancement of axial ratio (AR) bandwidth of a circularly polarized dielectric resonator antenna with a single feeding. To enhance the AR bandwidth, adjacent 3-dB AR passbands are merged by inserting the notches and conductive coating in the dielectric resonator. The dimensions of the notches and conductive coating are selected in such manner that impedance bandwidth remains approximately unchanged. The antenna provides the measured AR and impedance bandwidths of 55.22% and 66.45%, respectively.
TL;DR: In this article, a new differential microstrip feeding method was proposed for dielectric resonator antenna (DRA) and array with low permittivity, where two parallel microstrip lines with differential signals were placed underneath the rectangular DRA to excite its fundamental $\text{TE}^{x}_{\delta 11}$ mode.
Abstract: A new differential microstrip feeding method is proposed for dielectric resonator antenna (DRA) and array with low permittivity. Two parallel microstrip lines with differential signals are placed underneath the rectangular DRA to excite its fundamental $\text{TE}^{x}_{\delta 11}$ mode. A single-port DRA element is first designed with a balun. The measured −10 dB bandwidth is achieved to be 22% around 2.4 GHz, and the in-band realized boresight gain is around 6 dBi. Then, a 2 × 2 differentially fed DRA array is developed, combining series and parallel feeding networks. An 18.7% bandwidth and an average gain of 12.3 dBi are achieved. The effectiveness of our proposed feeding method has been demonstrated by the good agreement between the measured and simulated results.
TL;DR: In this article, a ring dielectric resonator antenna for multiple-input-multiple-output (MIMO) applications has been proposed, which includes two self-complementary hybrid radiators.
Abstract: This study investigates a wideband ring dielectric resonator antenna for multiple-input-multiple-output (MIMO) applications. The proposed MIMO antenna includes two self-complementary hybrid radiators. A microstrip line is used to excite both the stepped slots and the ring dielectric resonator. Wide impedance bandwidth is achieved by combining the resonance of both the stepped slots and dielectric resonator. The proposed MIMO antenna has aperture area of 31 × 50 mm
2
. The presented antenna obtains promising performance such as wide impedance bandwidth (82.75% for port 1 and 85.21% for port 2), good isolation between the antenna elements (20 dB), and stable radiation patterns. The proposed antenna is fabricated and tested in order to verify the simulated results. Various diversity performance parameters are also investigated. The values of these parameters lie within their acceptable limits.
TL;DR: In this article, a circularly polarised filtering dielectric resonator antenna is proposed to produce high selectivity, flat gain and wide stopband with high simulated radiation efficiency.
Abstract: A circularly polarised filtering dielectric resonator antenna is proposed. Left hand circularly polarised electromagnetic field is generated by virtue of a rectangular ring slot present on the ground plane of the dielectric laminate, beneath the dielectric resonator antenna, which is fed by a 50 Ω microstrip line. Additionally, a semi-elliptical shape bandpass filter is incorporated in the feed line to produce high selectivity, flat gain and wide stopband. A detailed analysis of the filter and the antenna has been carried out. The design offers fractional bandwidth of 6.13% ranging from 7.9 to 8.4 GHz, gain around 5.3 dBic and 3 dB axial ratio bandwidth of 3.68%. The simulated radiation efficiency is >80% in the pass band. The proposed structure has been fabricated and the results are compared with the simulated values.
TL;DR: In this paper, a low-profile omni-directional dielectric resonator antenna (DRA) was proposed, which achieved an impedance bandwidth covering the frequency range from 4.78 to 12.32 GHz.
Abstract: A new wideband low-profile omni-directional dielectric resonator antenna (DRA) is presented. By joining back-to-back two thin identical rectangular high-permittivity dielectric resonators (DRs) and feeding the arrangement with a microstrip feed line inserted in-between the DRs, an impedance bandwidth covering the frequency range from 4.78 to 12.32 GHz, or ~88.2%, is achieved. Importantly, the measured results show that the proposed low-profile DRA also provides a stable omni-directional radiation pattern with low cross-polarisation. The proposed antenna size is 12 × 24 × 2 mm
3
or ~0.191
λ
0
× 0.384
λ
0
× 0.032
λ
0
at 4.8 GHz.
TL;DR: In this paper, the realisation of an electronically tuned polarisation reconfigurable dielectric resonator antenna with multiple switchable states is described, where the antenna is fed by a microstrip line through a cross-slot aperture placed in the ground plane to achieve circular polarisation.
Abstract: The realisation of an electronically tuned polarisation reconfigurable dielectric resonator antenna with multiple switchable states is described in this study. The antenna is fed by a microstrip line through a cross-slot aperture placed in the ground plane to achieve circular polarisation. PIN diodes have been placed across the cross slots to control their effective dimensions and thereby its sense of polarisation. The antenna is connected to a microcontroller (ARDUINO-UNO) to switch between corresponding polarisation states. Simulated results of the antenna are verified with experimental data. The antenna has an impedance bandwidth of about 20% for all four states of polarisations. The antenna also radiates with a gain of 4 dB over the entire band.
TL;DR: In this article, the dielectric properties of the double perovskite (SMO) in radiofrequency (RF) have been studied and an equivalent circuit using three associations of R-CPE in parallel has been proposed.
TL;DR: In this paper, a high-gain circularly polarized dielectric resonator antenna is proposed for the fifth generation of a mobile network, where the parasitic elements are used to increase the antenna gain.
Abstract: A high-gain circularly polarized dielectric resonator antenna is proposed for the fifth generation of a mobile network. The parasitic elements are used to increase the antenna gain. By choosing suitable spacings among the elements, a significant increase in the gain of antenna can be obtained with no degradation in pattern characteristics. The dielectric constants of all elements are identical. The excited element is fed through an X-shaped slot coupled to a 50 Ω microstrip line. The proposed structure is designed, simulated, fabricated, and measured. The results show that the proposed antenna has about 5 GHz (17.8%) bandwidth, about 2.2 GHz axial ratio bandwidth, and also its gain is around 10.5 dB, which meet the requirements of the fifth generation mobile network.
TL;DR: In this article, a miniature high gain dielectric resonator antenna for RF energy harvesting application with high figure of merit to increase the power received is presented, where numerical approximation is used to assist the antenna design and modelling.
Abstract: Radio-frequency (RF) energy harvesting is a promising candidate for alternative power source that can reduce the dependencies on batteries. However, its power density is very low which makes it crucial to have a high gain antenna to increase the power received by the system. This study presents the design of miniature high gain dielectric resonator antenna for RF energy harvesting application with high figure of merit to increase the power received. Numerical approximation is used to assist the antenna design and modelling. The design focused on three parameters which are the width, length, and height of the dielectric resonator. The performance, electric field density, and the radiation patterns of the dielectric resonator antenna have been observed by varying the design parameters. The effect of air gap to the performance is investigated and it is found that 8.11–13% gain improvement and up to 36% improvement in impedance matching is achieved through incorporating thin air gap between the dielectric resonator. Soda-lime glass with relative permittivity 7.75 is used which allows miniaturization and transparency. Experimental results show reasonable agreement to the simulations. The work shows highest antenna gain with smallest size with high FOM at 5 GHz ISM band compared to previous works.
TL;DR: In this article, a novel circularly polarized (CP) dielectric resonator antenna (DRA) array is introduced, where the DRA element operating at the desired frequency is determined by the DWM, and two orthogonal modes are generated to excite CP waves.
Abstract: A novel circularly polarized (CP) dielectric resonator antenna (DRA) array is introduced. The DRA element operating at the desired frequency is determined by the dielectric waveguide model (DWM), and two orthogonal modes are generated to excite CP waves. A 4 × 4-element DRA array is then developed. The array is fed by the cavity-backed slotted substrate integrated waveguide, without using extra feeding network. Experimental results show that the array obtains a bandwidth of 240 MHz (9.88–10.12 GHz) for reflection coefficients and axial ratios (ARs) less than −10 dB and 1 dB, respectively. Moreover, the array obtains a 16 dBic peak gain, a −33.6 dB cross-polarization level at the boresight, namely 0.5 dB AR at the center frequency, which demonstrate the desirable array performance. In addition, above 62.5% aperture efficiency and above 90% radiation efficiency are realized over the operating bands, with about 76% peak aperture efficiency and about 94% peak radiation efficiency. The proposed array can be regarded as an element to form large planar arrays, which will be useful in beamforming systems. Our design idea may open a new way for developing high-efficiency large millimeter-wave arrays.
TL;DR: In this communication, some investigations have been performed on different forms of circular sectored-dielectric resonator antenna (CS-DRA) formed using different sector angles to improve the circularly polarized (CP) performance to achieve the orthogonal polarizations.
Abstract: In this communication, some investigations have been performed on different forms of circular sectored-dielectric resonator antenna (CS-DRA) formed using different sector angles $(\beta)$ to improve the circularly polarized (CP) performance. The additional parameters of CS-DRA are aspect ratio ( $\alpha$ ) and sector angle ( $\beta $ ), which constitute a new optimization framework to analyze CP parameters. These compact structures (CS-DRAs) with simple coaxial probe feeding offer low-volume geometry with wide axial-ratio (AR) bandwidth as compared to conventional DRAs. Based on the results obtained in this investigation, it is found that appropriate values of “ $\alpha $ ” and “ $\beta $ ” could be chosen to improve the CP performance in terms of wide AR, and thus could not be avoided. In this communication, the fundamental mode $\text{TM}_{v,1,\delta }$ and next lower resonant mode $\text{TM}_{2v,1, \delta }$ have been excited to achieve the orthogonal polarizations. CS-DRA with the best performance has been fabricated to validate the simulation results. Simulated and measured AR bandwidths obtained are 15.2% (5.47–6.37 GHz) and 15.46% (5.43–6.34 GHz), respectively, whereas input reflection coefficient bandwidths are 58.5% (4.24–7.75 GHz) and 48.3% (4.65–7.6 GHz), respectively.
23 Jan 2018
TL;DR: In this article, a dual band circularly polarized compact equilateral triangular dielectric resonator antenna (TDRA) is proposed and validated experimentally for microwave sensing applications and an innovative coupling based on dual facet spiral loop is used to bring down the axial ratio <3dB.
Abstract: In this article, a dual band circularly polarized compact equilateral triangular dielectric resonator antenna (TDRA) is proposed and validated experimentally for microwave sensing applications An innovative coupling based on dual facet spiral loop is used to bring down the axial ratio <3dB It basically creates the phase excitation on two side walls of the TDRA to ensure circular polarization near 75 and 87 GHz In addition to this, the TDRA confirms dual impedance band over (732768) GHz and (834944) GHz The demonstration shows good matching between the simulated and measured results This model can be a suitable candidate for high-sensitive sensing applications