Showing papers on "Dielectric resonator antenna published in 2015"

Apparatus and methods for transmitting wireless signals

Abstract: Aspects of the subject disclosure may include, for example, an antenna structure having a feed point for coupling to a dielectric core of a cable that propagates electromagnetic waves without an electrical return path, and a dielectric antenna, substantially or entirely devoid of conductive external surfaces, coupled to the feed point, the dielectric antenna facilitating receipt, at the feed point, the electromagnetic waves for propagating the electromagnetic waves to an aperture of the dielectric antenna for radiating a wireless signal. Other embodiments are disclosed.

Dielectric resonator antenna arrays

Abstract: A dielectric resonator antenna (DRA) array having an array feeding network and a parasitic patch array made up of individual antenna elements is provided with a dielectric lens made from a single piece of dielectric material in the form of a generally planar sheet. The sheet may be substantially coextensive with the DRA array so as to cover all of the antenna elements. The single piece of dielectric material has a plurality of dielectric portions defined by a plurality of holes through the sheet. Each dielectric portion may be positioned over one of the antenna elements. Adjacent dielectric portions are connected to each other along connecting edge portions thereof, and a single hole is defined through the sheet between connecting edge portions of a group of mutually adjacent dielectric portions.

A New Wideband Circularly Polarized Stair-Shaped Dielectric Resonator Antenna

Abstract: A circularly polarized stair-shaped dielectric resonator antenna (DRA) with a wideband circular polarization (CP) radiation is introduced for wireless local area network (WLAN) applications. This antenna is implemented by using two rectangular dielectric resonators (DRs), which are joined together to form a stair-shaped dielectric resonator antenna (DRA). In this structure, the excitation of multiple orthogonal modes leads to a wideband CP bandwidth. Measured results show that the proposed antenna has an axial ratio (AR) bandwidth of 22% (5.2–6.5 GHz), an impedance bandwidth of 37% (4.6–6.7 GHz), and a peak gain of 5.7 dB. In addition, the antenna radiation efficiency of more than 90% is achieved.

A Circularly Polarized Antenna by Using Rotated-Stair Dielectric Resonator

Abstract: In this letter, a wideband compact circularly polarized (CP) dielectric resonator antenna (DRA) is proposed. This antenna consists of two rectangular dielectric layers that are stacked with a rotation angle $\varphi $ relative to its adjacent bottom layer. The antenna is excited by an aperture coupled through a slot cutting on the ground plane. The rotated-stair configuration of DRA contributes dual broadside CP radiating modes and results in a noticeable enhancement in the axial ratio (AR) bandwidth. The proposed antenna achieves 31% impedance bandwidth and 18.2% AR bandwidth. The average gain within the AR bandwidth is 4.5 dBi with less than 0.5-dB variation. Moreover, the proposed dielectric resonator antenna has a low-profile structure. This work demonstrates a CP bandwidth broadening technique for the DRA. The potential applications of the antenna are 5G Wi-Fi and satellite communication systems.

A reduced size dual port MIMO DRA with high isolation for 4G applications

Abstract: © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:495-501, 2015. © 2014 Wiley Periodicals, Inc.A dual-port reduced size multiple input multiple output (MIMO) Dielectric Resonator Antenna (DRA) has been studied and proposed. The MIMO antenna consists of a Rectangular Dielectric Resonator antenna, which is fed by two symmetrical feed lines for orthogonal mode excitation. The proposed antenna is suitable for operation over various long term evolution (LTE) bands. A measured bandwidth of 264 MHz for |S 11 | <-10dB and isolation of 18 dB at 1.8 GHz has been obtained. Besides, the Envelope Correlation Coefficient, Mean Effect Gain and Diversity Gain have been studied for the presented MIMO DRA using the S-parameters. Based on these results, it can be concluded that the proposed antenna can be a suitable candidate for MIMO applications.

Dielectric Phase-Correcting Structures for Electromagnetic Band Gap Resonator Antennas

Abstract: A novel technique to design a phase-correcting structure (PCS) for an electromagnetic band gap (EBG) resonator antenna (ERA) is presented. The aperture field of a classical ERA has a significantly nonuniform phase distribution, which adversely affects its radiation characteristics. An all-dielectric PCS was designed to transform such a phase distribution to a nearly uniform phase distribution. A prototype designed using proposed technique was fabricated and tested to verify proposed methodology and to validate predicted results. A very good agreement between the predicted and the measured results is noted. Significant increase in antenna performance has been achieved due to this phase correction, including 9-dB improvement in antenna directivity (from 12.3 dBi to 21.6 dBi), lower side lobes, higher gain, and better aperture efficiency. The phase-corrected antenna has a 3-dB directivity bandwidth of 8%.

High resolution microwave microstrip resonator for sensing applications

Abstract: A microwave planar resonator with a very high quality factor is presented for sensing applications. The proposed resonator uses an active feedback loop with a microwave amplifier to generate negative resistance to compensate the resonator's loss and increases the loaded quality factor of the system. This high quality resonator is based on a planar microstrip resonator with a primary quality factor of 200. The active loop technique increases the primary quality factor up to 15,480 with no other material in its surrounding environment when measured at 1.55 GHz resonance frequency. The high quality factor of the designed resonator provides very high resolution for detection of permittivity variation in its ambient environment with a theoretical resolution of 0.1 ppb (10−10). It is experimentally demonstrated that the small permittivity variations such as that of foam (with permittivity very close to air) can be detected. The circuit demonstrated a resolution of 26 dB in amplitude for a 1 MHz variation in the frequency domain.

Wideband Fabry–Perot Resonator Antenna With Two Layers of Dielectric Superstrates

Abstract: This letter presents a new design of a Fabry–Perot resonator antenna (FPRA) with a wide gain bandwidth. A double-layered dielectric superstrate, which produces a reflection phase curve versus frequency with a positive slope, is used as a partially reflective surface (PRS) to enhance the bandwidth of the FPRA. For a physical insight, the PRS is analyzed by using the transmission line theory and Smith Chart. Experimental results demonstrate that the antenna has a 3-dB gain bandwidth over 13.5–17.5 GHz, relatively 25.8%, with a peak gain of 15 dBi. Furthermore, the gain band is overlapped well by the impedance band for the reflection coefficient ( ${ S}_{11}$ ) less than $-$ 10 dB.

Low-Profile Compact Circularly-Polarized Antenna Based on Fractal Metasurface and Fractal Resonator

Abstract: A novel low-profile and compact circularly-polarized (CP) antenna has been proposed and comprehensively investigated based on the combination of fractal metasurface and fractal resonator. The Hilbert shaped reactive impedance surface has improved the antenna performance in terms of low substrate thickness and good front-to-back ratio, and the Wunderlich-shaped fractal complementary split ring resonator with strong space-filling property achieves the CP property and further size reduction. For application, a CP antenna working at the Wimax band is numerically and experimentally studied. The results indicate that the proposed antenna achieves a compact layout of $40~\hbox{mm} \times 45~\hbox{mm} \times 2.5~\hbox{mm}$ at 3.5 GHz, a relative wide bandwidth of more than 1.86% and also a comparable gain of about 6.3 dBic. The strategy does not require any metallic via holes, sophisticated feeding networks or truncated corners, predicting promising applications in portable communication systems.

Novel Design of Compact UWB Dielectric Resonator Antenna With Dual-Band-Rejection Characteristics for WiMAX/WLAN Bands

Abstract: A novel compact dual band-notched dielectric resonator antenna (DRA) for ultrawideband (UWB) applications is proposed Here, the bandwidth enhancement and the first band notch is realized by embedding a stub that is located to the hollow center of a U-shaped feedline simultaneously By etching an inverted T-shaped parasitic strip at the back plane of an antenna that is surrounded by a dielectric resonator (DR), the second band rejection is created By cutting a slot at the proper position on the ground plane, the width of the second band notch is controlled The proposed antenna size is $12 \times 30 \times 6~\hbox{mm}^{3}$ or about $0124 \lambda \times 031 \lambda \times 0062 \lambda $ at 31 GHz The measurement results demonstrate that the proposed DRA provides acceptable radiation performances such as an ultra-wide impedance bandwidth of around 122% with two sufficient band rejections in the frequency bands of 322–406 and 484–596 GHz, high radiation efficiency, and nearly constant gain

Circularly Polarized Spidron Fractal Dielectric Resonator Antenna

Abstract: In this letter, a circularly polarized Spidron fractal dielectric resonator antenna is presented. A wide 3-dB axial ratio (AR) bandwidth is realized by merging a Spidron fractal dielectric resonator and a C-shaped slot that can produce circular polarization. The proposed antenna is excited through the coupling between a C-shaped slot in the ground plane and a ${\hbox {50-}} \Omega $ microstrip feeding line. A prototype of the antenna is fabricated and tested. Reasonable agreement is achieved between the measurement and simulation. The experimental results show that the proposed antenna has a $-$ 10- $\hbox{dB}$ reflection bandwidth of 37.29% (4.32–6.30 GHz) and a 3-dB AR bandwidth of 11.57% (5.13–5.76 GHz). The measured gain of the antenna ranges 2.20 dBic to 3.16 dBic within the AR bandwidth.

Triple-Mode Dielectric Resonator Diplexer for Base-Station Applications

Abstract: This paper proposes a novel diplexer based on triple-mode dielectric-loaded cylindrical cavities. Such two metal cavities are designed to achieve two different frequency bands, while three resonant modes of a single cavity are classified as a TM mode and a pair of hybrid (HE) degeneration modes. An off-centered dielectric resonator instead of a traditional corner cuts perturbation or screws perturbation properly perturbs the two degenerate modes in the same cavity. Extensive study is then conducted to design this proposed diplexer. Finally, a diplexer prototype is fabricated using a brass cavity and it is tested for experimental verification of the predicted results. Good agreement between measurement and simulation is achieved.

A Wideband Circularly Polarized Rectangular Dielectric Resonator Antenna Excited by an Archimedean Spiral Slot

Abstract: A wideband circularly polarized (CP) rectangular dielectric resonator antenna (DRA) is presented. An Archimedean spiral slot is used to excite the rectangular DRA for wideband CP radiation. The operating principle of the proposed antenna is based on using a broadband feeding structure to excite the DRA. A prototype of the proposed antenna is designed, fabricated, and measured. Good agreement between the simulated and measured results is attained, and a wide 3-dB axial-ratio (AR) bandwidth of 25.5% is achieved.

A High-Gain Dual-Band EBG Resonator Antenna with Circular Polarization

Abstract: A dual-band circularly polarized (CP) electromagnatic band-gap (EBG) resonator antenna (ERA) is presented. The antenna employs an all-dielectric superstructure, which consists of two identical unprinted dielectric slabs, and a dual-band corner-truncated patch feed. A prototype antenna is fabricated and tested using a superstructure made out of 3.175-mm-thick Rogers TMM10 material. Measured peak gains are 16.1 dBic [left-hand circular polarization (LHCP)] and 16.2 dBic [right-hand circular polarization (RHCP)], measured radiation efficiencies are 93% and 91%, and the boresight axial ratios are 1.9 and 1.5 dB at 9.65 and 11.75 GHz, respectively. This dual-band antenna is easy to fabricate, making it suitable for high-gain low-cost CP applications.

A Compact Frequency-Reconfigurable Dielectric Resonator Antenna for LTE/WWAN and WLAN Applications

Abstract: A compact frequency-reconfigurable dielectric resonator antenna (DRA) for LTE/WWAN and WLAN applications is investigated and presented. The proposed antenna provides the frequency tuning between 1.60 and 2.71 GHz. The design consists of four identical rectangular dielectric resonators with permittivity of 10 each and three p-i-n diode switches that are located on the feedline network between each of two dielectric resonators. The proposed antenna size is $20 \times 36 \times 5.57~\hbox{mm}^3$ , which is suitable for mobile devices. The measurement and simulation results are applied to demonstrate the performance of the proposed antenna. From the measured results, it is found that the proposed antenna with acceptable performance provides four single-band modes with the impedance bandwidths of 17%, 11%, 14%, and 6%.

Optically detected magnetic resonance imaging with an electromagnetic field resonator

Abstract: Measuring a sample includes providing a magnetic field at the sample using an electromagnetic field resonator. The electromagnetic field resonator includes two or more resonant structures at least partially contained within dielectric material of a substrate, at least a first resonant structure configured to provide the magnetic field at the sample positioned in proximity to the first resonant structure. The sample is characterized by an electron spin resonance frequency. A size of an inner area of the first resonant structure and a number of resonant structures included in the electromagnetic field resonator at least partially determine a range of an operating resonance frequency of the electromagnetic field resonator that includes the electron spin resonance frequency. Measuring the sample also includes receiving an output optical signal from the sample generated based at least in part on a magnetic field generated by the electromagnetic field resonator.

Circularly Polarized Semi-Eccentric Annular Dielectric Resonator Antenna for X-Band Applications

Abstract: In this letter, a compact single-feed circularly polarized dielectric resonator antenna is proposed for X-band applications. The radiator comprises a semi-eccentric annular dielectric resonator (DR), which is a semi-elliptical DR with a hollow elliptical cylinder. A vertical coaxial probe is located adjacent to a cutting surface of the DR to excite the proposed antenna. The two main design parameters, the aspect ratio of the elliptical DR and the feeding position, were optimized, and a prototype of the antenna was fabricated and tested. The experimental results exhibit a $-$ 10-dB reflection bandwidth of 29.14% (9.41–12.62 GHz) and a 3-dB axial-ratio bandwidth of 5.71% (10.37–10.98 GHz). The measured peak gain varies from 4.17 to 4.78 dBic.

Compact Quad-Mode Bandpass Filter Using Modified Coaxial Cavity Resonator With Improved $Q$ -Factor

Abstract: This paper presents a novel quadruple-mode coaxial cavity resonator and its application to bandpass filters with compact size and improved quality factor ( $Q$ -factor). Unlike the conventional coaxial cavity resonator, the proposed resonator is made up of four inner conductive posts within a single cavity, which provides new quadruple resonant modes to realize bandpass filter. No metallic walls inside the cavity are required, and thus the utilization efficiency of the cavity space is improved. As a result, the unloaded $Q$ can be approximately 15% higher in comparison to the conventional coaxial resonator, or 30%–35% volume saving can be achieved while maintaining the similar $Q$ -factor value with the conventional designs. In addition, due to the multiple cross-coupling occurring within the cavity, including the source-to-load direct coupling, four flexible transmission zeros can be created to realize different filtering functions. The complete design methodology of filters based on the proposed resonator is discussed, starting with the resonator characteristics and the coupling scheme. Simulations as well as experimental results of four- and eight-pole filters are presented to validate this attractive design concept. Good agreement between measured and computed results is obtained.

K-Band Substrate-Integrated Waveguide Resonator Filter With Suppressed Higher-Order Mode

Abstract: In this letter, we present a design method for K-band substrate-integrated waveguide (SIW) resonator filters utilizing ${\rm TM}_{02}$ mode. More importantly, a methodology for suppressing an unwanted higher-order mode ( ${\rm TM}_{11}$ ) close to the passband is demonstrated. It is shown that suppressing the unwanted mode give rise to the improved stopband performance. In addition, the resonator used in this filter design has capability of adjusting the resonant frequency, and this allows for compensating the fabrication error. Verification of the presented design method has been carried out by fabricating and measuring the filter.

Reduced size patch antenna using complementary split ring resonator as defected ground plane

Abstract: In this paper, the authors have presented a reduced size metamaterial loaded circular microstrip patch antenna. In the present work, complementary split ring resonator is loaded in the ground plane of circular microstrip patch antenna is. The unloaded circular microstrip patch antenna resonates at 6.11 GHz, whereas after loading it with complementary split ring resonator, the same antenna resonates near 6.11 GHz with reduced size. The effective footprint of the antenna is reduced by nearly 64% compared to the conventional patch antenna. The gain of the metamaterial loaded antenna structure is 5.04 dB.

A Compact Wideband Rectangular Dielectric Resonator Antenna using Perforations and Edge Grounding

Abstract: A compact wideband rectangular dielectric resonator antenna (RDRA) is investigated and presented Perforations improve bandwidth by lowering down the quality factor The perforations are an array of symmetrical square-shaped slots drilled uniformly on the RDRA On choosing the optimal size of slots and distance between two consecutive slots, the fundamental ${\rm TE}_{111}$ mode of the RDRA is preserved This aids in making the geometry compact by employing edge grounding The coaxial probe acts like a monopole that further improves bandwidth by matching, monopole, and higher-order ${\rm TE}_{131}$ -like mode of the RDRA in the frequency band (272–43 GHz) The proposed geometry offers a wide impedance bandwidth of 56% for ${{ S}_{11}} The measured results show that the radiation efficiency of the proposed antenna is above 85% for the complete bandwidth with the stable radiation pattern

Micromachined On-Chip Dielectric Resonator Antenna Operating at 60 GHz

Abstract: This paper presents a novel cylindrical dielectric resonator antenna (DRA) suitable for millimeter-wave (mm-wave) on-chip systems. The antenna was fabricated from a single high-resistivity silicon wafer via micromachining technology. The new antenna was characterized using HFSS and experimentally with good agreement been found between the simulations and experiment. The proposed DRA has good radiation characteristics, where its gain and radiation efficiency are 7 dBi and 79.35%, respectively. These properties are reasonably constant over the working frequency bandwidth of the antenna. The return loss bandwidth was 2.23 GHz, which corresponds to 3.78% around 60 GHz. The antenna was primarily a broadside radiator with $-15\hbox{-dB}$ cross-polarization level.

Cross-Polarized Radiation in a Cylindrical Dielectric Resonator Antenna: Identification of Source, Experimental Proof, and Its Suppression

Abstract: In this communication, cross-polarized (XP) radiation of cylindrical dielectric resonator antenna (CDRA) has been investigated with a view to identify the source of the same. The study starts with a conjecture, which has been established through a systematic study using simulated results. The inference has been verified experimentally with the help of a set of prototypes. ${\rm{HEM}_{21\delta }}$ has been identified as the XP generating mode and a small metallic grounded post of circular cross section has been conceived to perturb the same to prove the conjecture. This insight has been extended to demonstrate a practical application indicating a possibility of achieving up to 8–10-dB suppression in XP radiation from a CDRA.

Circularly Polarized Dielectric Resonator Antenna Fed by Off-Centered Microstrip Line for 2.4-GHz ISM Band Applications

Abstract: A special feeding technique of an off-centered microstrip feedline slot-coupled circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) for 2.4-GHz industry, science and medicine (ISM) band applications is reported in this letter. Good CP characteristics can be achieved using two coupling points with a quarter-wavelength path difference and $90^\circ $ phase shift, resulting in a series feeding circuitry. The 10-dB impedance bandwidth and the 3-dB axial ratio of the proposed antenna are 141 and 85 MHz, respectively. Details of the antenna design procedure are described and typical experimental results are presented and discussed.

Dielectric resonator antenna

Abstract: This article is focused on using a dielectric resonator as a radiating element of a antenna with the aim to reduce dimensions of such antennas compared to classical microstrip antennas. Such antenna was build and its parameters tested in frequency band of 2.9 to 3.1 GHz.

Compact Unidirectional Ring Dielectric Resonator Antennas With Lateral Radiation

Abstract: A compact unidirectional ring dielectric resonator (DR) antenna (DRA) with lateral radiation patterns is investigated for the first time. The unidirectional patterns are obtained by combining an equivalent horizontal magnetic dipole of the DR $\text{HEM}_{{11\delta} + {1}}$ mode and a vertical electric dipole located at the center of the DR. A wideband version of the design is also investigated, in which the higher-order DR $\text {HEM}_{{11\delta} + {2}}$ mode is excited and merged with a slot mode to give a wideband magnetic dipole. The wideband electric dipole is obtained by making use of the parasitic effect of the DR. To demonstrate the idea, the original and wideband DRAs were designed in WLAN (2.40–2.48 GHz) and WiMax (3.4–3.7 GHz) bands, respectively. Their prototypes were fabricated and measured, and reasonable agreement between the measured and simulated results was obtained. In each design, the measured and simulated front-to-back radiation ratios are both over 15 dB, with measured and simulated 3-dB beamwidths of at least 117°.

Acoustic resonator and method of manufacturing the same

Abstract: There is provided an acoustic resonator including: a resonance part including a first electrode, a second electrode, and a piezoelectric layer interposed between the first and second electrodes; and a substrate provided below the resonance part, wherein the substrate includes at least one via hole penetrating through the substrate and a connective conductor formed in the via hole and connected to at least one of the first and second electrodes. Therefore, reliability of the connective conductor formed in the substrate may be secured.

Tunable soi laser

Abstract: A wavelength tunable silicon-on-insulator (SOI) laser comprising: a laser cavity including: a semiconductor gain medium having a front end and a back end, wherein a mirror of the laser cavity is located at the back end of the semiconductor gain medium; and a phase-tunable waveguide platform coupled to the front end of the semiconductor gain medium, the phase-tunable waveguide platform comprising: a first resonator and a second resonator; at least one resonator being a phase-tunable resonator; wherein the first resonator is any one of: an MMI device including a pair of reflective surfaces defining a resonator cavity therebetween such that the device is configured to act as a Fabry-Perot filter; a ring resonator; or a waveguide Fabry-Perot filter; and wherein the second resonator is any one of: an MMI device including a pair of reflective surfaces defining a resonator cavity therebetween such that the device is configured to act as a Fabry-Perot filter; a ring resonator; or a waveguide Fabry-Perot filter.

Nonresonant Microstrip Patch-Fed Dielectric Resonator Antenna Array

Abstract: A cylindrical dielectric resonator antenna (CDRA) fed by nonresonant microstrip patch excites ${\rm HEM}_{12\delta}$ mode for efficient radiation. A $2 \times 2$ antenna array with such an antenna element is designed at the center frequency of 9.04 GHz for obtaining higher directive gain. A prototype has been fabricated with FR-4 substrate, and experimental measurements have been carried out. The array offers an impedance bandwidth of 2.9% and a maximum gain of 14.8 dBi at the operating frequency. A good agreement has been obtained between the measured and simulated results.

Multi-band antenna with a battery resonator

Abstract: Systems and techniques are provided for multi-band antenna with a battery resonator. An antenna may include a ground plane, a front ground plane extension and a rear ground plane extension attached to the ground plane, a dielectric layer, an antenna layer, and a battery. The dielectric layer may include dielectric material placed over the front ground plane extension. The dielectric layer may be in between the antenna layer and the front ground plane extension. The antenna layer may include a high frequency antenna element and a low frequency antenna element attached to a transmission line. The battery may be placed in between and proximity coupled to the front ground plane extension and the rear ground plane extension. The front ground plane extension, rear ground plane extension, ground plane and battery may be proximity coupled to the low-frequency antenna element.