Higher Order Mode Excitation for High-Gain Broadside Radiation From Cylindrical Dielectric Resonator Antennas
TL;DR: In this paper, a cylindrical dielectric resonator antenna (CDRA) has been examined with a view for using it as another radiating mode with broadside radiation patterns.
Abstract: A resonant mode (HEM12δ), other than those ( HEM11δ and TM01δ) conventionally excited and used in a cylindrical dielectric resonator antenna (CDRA) has been examined with a view for using it as another radiating mode with broadside radiation patterns. Excitation of the mode, being the most challenging aspect, has been discussed and resolved by employing an innovative technique. The proposed concept has been successfully verified and experimentally demonstrated for the first time. More than 8-dBi peak gain with excellent broadside radiation has been obtained from a prototype shaped from a commercially available low-loss dielectric material with relative permittivity 10.
Citations
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TL;DR: In this paper, a comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented.
Abstract: A comprehensive review concerning the geometry, the manufacturing technologies, the materials, and the numerical techniques, adopted for the analysis and design of wideband and ultrawideband (UWB) antennas for wireless applications, is presented. Planar, printed, dielectric, and wearable antennas, achievable on laminate (rigid and flexible), and textile dielectric substrates are taken into account. The performances of small, low-profile, and dielectric resonator antennas are illustrated paying particular attention to the application areas concerning portable devices (mobile phones, tablets, glasses, laptops, wearable computers, etc.) and radio base stations. This information provides a guidance to the selection of the different antenna geometries in terms of bandwidth, gain, field polarization, time-domain response, dimensions, and materials useful for their realization and integration in modern communication systems.
106 citations
TL;DR: In this paper, a spoof plasmon (SP)-based slow-wave feeding configuration is proposed, experimentally verified and exploited to excite the fundamental horizontally polarized mode of dielectric resonator antennas (DRAs).
Abstract: A spoof plasmon (SP)-based slow-wave feeding configuration is proposed, experimentally verified and exploited to excite the fundamental horizontally polarized mode of dielectric resonator antennas (DRAs). As an example, a cylindrical DRA operating at 3 GHz is fed by the proposed feeding structure. The simulation and measurement evidence the unique features of ${\rm TE}_{01\updelta}$ mode such as lower thickness-dependency of the resonant frequencies, superb miniaturization and ultra-compactness, and omnidirectional radiation for horizontally polarized waves. We anticipate that the ground-free SP-based feeding technique could be applied to effectively excite the more “unusual” modes of the isolated DRAs.
93 citations
TL;DR: In this article, a low profile stacked dielectric resonator antenna (DRA) and a microstrip metasurface (MS) antenna are investigated and compared in this communication.
Abstract: A low profile stacked dielectric resonator antenna (DRA) and a microstrip metasurface (MS) antenna are investigated and compared in this communication. It has been found that very similar radiation performance including resonant modes, reflection coefficients, boresight gains, and radiation patterns can be obtained between them, indicating that the dielectric superstrate of stacked DRA plays analogous role with MS in enhancing the antenna bandwidth and realized gain. Based on this observation, a broadband, low profile, and high gain filtering cylindrical stacked DRA is inspired by an MS-based filtering antenna. Four resonant modes including the higher order HEM $_{31\delta }$ mode and HEM $_{13\delta }$ mode are simultaneously excited in the DRA to provide a broad bandwidth of 61.4% and a peak gain of 11.4 dBi within passband, whereas a shorting via and two pairs of transverse stubs are introduced into the feeding microstrip line to generate radiation nulls in stopband and realize filtering function. Second harmonic suppression has been achieved without increasing the footprint of the antenna, and an out-of-band suppression of more than 23 dB is obtained within the wide stopband.
78 citations
Cites methods from "Higher Order Mode Excitation for Hi..."
...The higher order HEM12δ mode has been investigated recently in designing dualband DRAs [19], [21]–[23], but it is the first time to utilize the HEM31δ and HEM13δ modes in DRA design although they have been studied theoretically in [20]....
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TL;DR: A meaningful comparative study where all commonly used feed mechanisms such as coaxial probe, microstrip line, and rectangular aperture for both antennas operating near the same frequency is considered, indicating relative advantages and disadvantages.
Abstract: Microstrip patches and dielectric resonators (DRs) are two low-profile variants of modern microwave and wireless antennas. However, the DR antenna (DRA) is relatively new and still passing through the stages of development. Both variants are quite similar in terms of performance and characteristics. This article focuses on a meaningful comparative study where we have considered all commonly used feed mechanisms such as coaxial probe, microstrip line, and rectangular aperture for both antennas operating near the same frequency. Circular geometry, i.e., cylindrical DRA (CDRA) and circular microstrip patch antenna (CMPA), have been chosen, and a systematic investigation based on thorough experiments has been executed. Multiple sets of prototypes have been fabricated and measured at 4 GHz. All available data have been furnished and compared, indicating relative advantages and disadvantages. This comparative study should provide qualitative and quantitative instructions to a designer for choosing the right element and corresponding feed based on design requirement and feasibility.
71 citations
TL;DR: In this article, a composite aperture has been conceived to excite cylindrical dielectric resonator antenna (CDRA) simultaneously with two different modes, resulting in broadside radiations at two adjacent bands.
Abstract: A composite aperture has been conceived to excite cylindrical dielectric resonator antenna (CDRA) simultaneously with two different modes, resulting in broadside radiations at two adjacent bands. Threefold objectives of this investigation includes: (i) to realize ${\rm HEM}_{{12\delta}}$ mode in a practical CDRA without involving any unwanted hybrid mode; (ii) to explore composite aperture type feed, which serves as equivalent magnetic and electric dipoles to launch ${\rm HEM}_{{11\delta}}$ mode and ${\rm HEM}_{{12\delta}}$ mode, respectively; and hence (iii) to achieve a dual-mode dualband CDRA without compromising in any enlargement of antenna dimension. ${\rm HEM}_{{12\delta}}$ mode is a recent introduction by the present authors as a broadside radiating mode in a CDRA, although this investigation demonstrates a practically feasible application for the first time. Systematic study of newly proposed composite aperture is followed by experimental investigation with a set of prototypes operating at S and C bands. As much as 6 dBi gain with 7–8% matching bandwidth for each operating band has been experimentally demonstrated.
64 citations
Cites background from "Higher Order Mode Excitation for Hi..."
...Present authors became successful by introducing a new concept in feed, which resembles an electric current ribbon [4] and induces mode in a CDRA....
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...The current ribbon [4] excites pure mode (radiating) over a narrow matching bandwidth along with a hybrid mode (non-radiating)....
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...Yet another radiating mode has been realized very recently [4], which also...
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...But the feed configuration explored in [4] is not stable and commercially viable....
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...Compared to earlier feeds, explored in [4] and [8], the present...
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References
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TL;DR: In this article, an experimental investigation of the radiation and circuit properties of a resonant cylindrical dielectric cavity antenna has been undertaken, and a simple theory utilizing the magnetic wall boundary condition is shown to correlate well with measured results for radiation patterns and resonant frequencies.
Abstract: An experimental investigation of the radiation and circuit properties of a resonant cylindrical dielectric cavity antenna has been undertaken. The radiation patterns and input impedance have been measured for structures of various geometrical aspect ratios, dielectric constants, and sizes of coaxial feed probes. A simple theory utilizing the magnetic wall boundary condition is shown to correlate well with measured results for radiation patterns and resonant frequencies.
1,434 citations
"Higher Order Mode Excitation for Hi..." refers background in this paper
...[1] and since then, cylindrical dielectric resonator antennas (CDRAs) are probably the most celebrated ones in terms of investigations and applications....
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...Long [1] first used the hybrid electromagnetic...
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15 Apr 2005
TL;DR: Linearly and circularly polarized conformal strip-fed dielectric resonator antennas (DRAs) are studied in this article, where a parasitic patch is used to excite a nearly degenerate mode.
Abstract: Linearly and circularly polarized conformal strip-fed dielectric resonator antennas (DRAs) are studied in this article. In the latter case, a parasitic patch is used to excite a nearly degenerate mode. The hemispherical DRA, excited in its fundamental broadside TE111 mode, is used for the demonstration. In the analysis, the mode-matching method is used to obtain the Green's functions, whereas the method of moments is used to solve for the unknown strip currents. In order to solve the singularity problem of the Green's functions, a recurrence technique is used to evaluate the impedance integrals. This greatly increases the numerical efficiency. Measurements were carried out to verify the calculations, with good results.
Keywords:
circularly polarized antenna;
dielectric antennas;
mode-matching methods;
moment methods;
parasitic antennas;
resonance
898 citations
Additional excerpts
...The value of can be calculated in terms of the DRA parameters using a closed-form expression, readily available in any DRA book [9], [10]....
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01 Aug 1959
TL;DR: In this paper, the radiansphere is defined as the boundary between the near field and the far field of a small antenna, and the power that can be intercepted by a hypothetical isotropic antenna is that which flows through the radianphere or its cross section, the "radiancircle."
Abstract: The "radiansphere" is the boundary between the near field and the far field of a small antenna. Its radius is one radianlength (?/2?), at which distance the three terms of the field are equal in magnitude. A "small" antenna is one somewhat smaller than the radiansphere, but it has a "sphere of influence" occupying the radiansphere. The power that theoretically can be intercepted by a hypothetical isotropic antenna is that which flows through the radiansphere or its cross section, the "radiancircle." From a small electric dipole, the far field of radiation is identified as a retarded magnetic field. Between two such dipoles, the far mutual impedance is that of mutual inductance, expressed in terms of space properties and the radiansphere. A small coil wound on a perfect spherical magnetic core is conceived as an ideal small antenna. Its radiation power factor is equal to the ratio of its volume over that of the radiansphere. A fraction of this ratio is obtainable in various forms of small antennas (C or L) occupying a comparable amount of space. A radiation shield, in the form of a conducting shell the size of the radiansphere, enables separate measurement of radiation resistance and loss resistance.
593 citations
"Higher Order Mode Excitation for Hi..." refers methods in this paper
...Radiation efficiency at each resonant mode has been measured by the Wheeler cap technique [11], which indeed uses input resistances of an antenna with and without the Wheeler cap....
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TL;DR: In this article, electric and magnetic field patterns for five of the lowest resonant modes in cylindrical dielectic resonators are displayed in various planes of intersection, based on a method moments solution of the surface integral equation for bodies of revolution.
Abstract: Electric- and magnetic-field patterns for five of the lowest resonant modes in cylindrical dielectic resonators are displayed in various planes of intersection. The computational procedure is based on a method moments solution of the surface integral equation for bodies of revolution. Improvement of the numerical stability through the normalization of the matrix is discussed, and an algorithm for the evaluation of the modal field components is described.
261 citations
TL;DR: In this paper, a moment method solution procedure for rotationally symmetric dielectric bodies has been applied to isolated cylindrical D resonators, and the frequencies, as well as Q factors due to radiation, have been determined for several of the lowest modes, including those of hybrid type.
Abstract: A moment method solution procedure for rotationally symmetric dielectric bodies has been applied to isolated cylindrical dielectric resonators, and the frequencies, as well as Q factors due to radiation, have been determined for several of the lowest modes, including those of hybrid type.
168 citations