Cylindrical Dielectric Resonator Research Articles

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

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 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">°</sup> 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.

Annular Column Loaded Cylindrical Dielectric Resonator Antenna for Wideband Conical Radiation

A wideband cylindrical dielectric resonator antenna (CDRA)-loaded with an annular column, namely the LCDRA, is proposed and analyzed. The antenna comprises two components—an inner cylindrical dielectric and a loaded concentric column dielectric. The proposed antenna is centrally fed by a coaxial probe, and has a low profile of $0.175\;{\lambda _0}$ ( ${\lambda _0}$ is the wavelength of the center frequency). Four conical radiation pattern modes ( ${\text{TM}_{01\delta }},{\text{TM}_{02\delta }},{\text{TM}_{03\delta }},\;\text{and}\;{\text{TM}_{04\delta }}$ modes) are excited and merged, providing an impedance bandwidth of 56% (3.14–5.56 GHz). A prototype of the proposed antenna is built and tested. Good agreement between the simulated and measured results, including the reflection coefficient and radiation patterns, is achieved.

Study on Dielectric Resonator Antenna with Annular Patch for High Gain and Large Bandwidth

A new high-gain cylindrical Dielectric res- onator antenna (DRA) with a large bandwidth is proposed. A cylindrical Dielectric resonator (DR), a double-annular patch and a metallic cylinder are used to obtain a large bandwidth and a high gain. The mode TM12 excited in the patch is used to enhance the gain of the DRA, and the cavity formed by the metallic cylinder provides a further higher gain and a larger bandwidth. The measured results demonstrate that the proposed DRA achieves a large band- width of 23% from 5.3 to 6.8GHz with VSWR less than two and a high gain around 11 dBi. In this paper, a new broadband, high-gain DRA design is proposed using a double-annular patch and a conducting cav- ity formed by a concentric metallic cylinder. Firstly, a single- annular patch is used to improve the gain of the DRA. After- ward, a double-annular patch is used to achieve a large gain bandwidth. Finally, a metallic cylinder is introduced to en- hance the resonating and obtain a higher gain. The antenna is manufactured and measured in the microwave anechoic cham- ber. The results of simulations and measurements are com- pared together, showing a good agreement. The results show that the antenna provides a further higher gain and a larger bandwidth using the proposed double-annular patch and a metallic cylinder.

Triple band two‐segment cylindrical dielectric resonator antenna with a novel microstrip feed for WLAN/WIMAX applications

ABSTRACTIn this letter, a triple band two‐segment cylindrical dielectric resonator antenna with a partial ground plane is investigated. Proposed antenna is excited by a novel microstrip feed that having a microstrip line along with two ring patches. Proposed triple band antenna has been analyzed, studied, and optimized using Ansoft HFSS simulation software. Prototype of proposed structure has been fabricated and tested. Good agreement has been obtained between simulated and measured parameters. The proposed design operates in three different frequency bands, that is, 2.3–2.5 GHz; 3.2–3.8 GHz; 4.67–7.0 GHz with the fractional bandwidth of 8.33%; 17.14%, and 39.93%, respectively. Proposed antenna is able to cover three frequency bands for different wireless applications (WLAN [2.4/5.2/5.8 GHz] and WiMAX [3.5/5.5 GHz] bands). © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2649–2655, 2015

Probe feed half split cylindrical dielectric resonator antenna for wideband application

In this paper, wideband half split cylindrical dielectric resonator antenna (CDRA) using coaxial probe feed has been designed and fabricated. The input impedance and radiation characteristics of the proposed antenna were determined through the Ansoft HFSS and CST Microwave Studio simulation software. Simulation results are compared with measured results. The proposed antenna provides wide impedance bandwidth (51%) and peak gain of 5.94dBi. The proposed antenna is excited as dominant TM01δ mode with monopole-like radiation pattern having low cross polarization. Proposed antenna may find suitable application in 5.0GHz WLAN and WiMAX Band.

Micromachined On-Chip Dielectric Resonator Antenna Operating at 60 GHz

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.

Rounded bevel shaped fed cylindrical dielectric resonator antenna for wideband applications

ABSTRACTA cylindrical dielectric resonator antenna fed by a rounded bevel shaped patch has been proposed in this letter. The antenna structure uses coplanar waveguide technique with truncated ground plane. The cylindrical dielectric resonator (DR) loads the patch at low frequencies and also adds its own resonances to obtain a wideband performance. The proposed antenna structure achieves a measured impedance bandwidth of 124.4% covering frequency range from 4.4 to 18.9 GHz. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2364–2368, 2015

CDR antenna with dual‐band 1.9/2.7 GHz for MIMO‐LTE terminals

ABSTRACTIn this letter, we present a compact dual‐band dielectric resonator antenna for multi‐input multi‐output antenna is designed and fabricated. The proposed antenna consists of a single cylindrical dielectric resonator antenna (CDRA) excited from two orthogonal ports. The electromagnetic analysis is performed using the CST microwave studio software. To validate the proposed concept, experimental measurements are also performed. The measured results show that the CDRA provides two bands around 1.9 and 2.7 GHz, suitable for LTE applications. Moreover, the proposed design allows a very good isolation between the two ports and a low envelop correlation coefficient. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2388–2391, 2015

Analysis of Different Waveguide Modes of a Cylindrical Dielectric Resonator Antenna for Wireless Communications

Analysis of Different Waveguide Modes of a Cylindrical Dielectric Resonator Antenna for Wireless Communications

Design of a novel dielectric resonator antenna using MgTiO3–CoTiO3 for wideband applications

Abstract In this work, a novel low profile design of a cylindrical dielectric resonator (DR) antenna with two different permittivity materials is proposed for wideband applications. The multi-permittivity cylindrical DR (MPCDR) was formed by combining four 90° sectors whereby sectors with the same permittivity were positioned in opposite quadrants. Simulation of the antenna was performed in the time domain using computer simulation technology (CST 2014). A systematic analysis was carried out to optimize the antenna's sector size and permittivity. The prototype was fabricated using MgTiO3 (MTO) and CoTiO3 (CTO) dielectric materials prepared via solid state reaction. MTO and CTO were sintered at 950 °C (4 h) and subsequently analyzed by XRD to confirm the presence of a single phase. The dielectric properties of MTO and CTO were studied by electrical characterization; it was found that MTO and CTO have permittivity values of 15.72 and 9.85, respectively. The antenna performance was analyzed by placing the MPCDR on top of a microstrip line with an angular position (θ) of 27.5° with respect to the longitudinal axis of the feed-line. An impedance bandwidth up to 56% with stable broadside radiation pattern was achieved in both the simulation and measured.

Parametric Study of Cylindrical Dielectric Resonator Antenna (CDRA) Feeder with Symmetric Parabolic Reflector

In this study a parabolic reflector antenna is designed and fabricated for IEEE 802.11a WLAN application. Initially, a single element circular tuning slot coupled Cylindrical Dielectric Resonator Antenna (CDRA) feeder is designed and fabricated for a symmetric parabolic reflector. Subsequently, the designed feeder is integrated at the focal point of the parabolic reflector to provide unidirectional radiation pattern with improved gain and sidelobe levels. The measured fractional impedance bandwidth achieved for the proposed antenna is 1.8% for S₁₁<-10 dB from 5.32 to 5.52 GHz. A radiation pattern with broadside radiation and low back radiation has been obtained. A good measurement gain of approximately 13 dB is achieved over the bandwidth by placing CDRA feeder at the focal point of the parabolic reflector. In addition, a comprehensive parametric study has been conducted to realize the effect of slot size and position on the resonance frequency of the designed feeder. Furthermore, a parametric study of various reflector parameters has also been performed to study the effect of size, depth and focal point of the parabolic reflector on gain of the antenna. Important design factors have been identified from the parametric study of the antenna. The experimental and measured results show that the designed antenna is suitable for IEEE WLAN 802.11a wireless application.

Investigation on Cylindrical Dielectric Resonator Antenna with Metamaterial Superstrate

The simulation and experimental studies of a probe-fed dual segment cylindrical dielectric resonator antenna with metamaterial superstrate are presented in this paper. The antenna consists of a ceramic material (SrLa2Mg2W2O12) of dielectric constant ?r = 22 and loss tangent tan ? = 0.0021 acting as upper segment and commercially available Teflon having dielectric constant of 2.1 acting as lower segment. The infinity-shaped metamaterial has been used as superstrate. The simulation study has been carried out using Ansys's high frequency structure simulator (HFSS) software. The variation of reflection coefficient with frequency, radiation pattern, and gain of the antenna with and without metamaterial superstrate were simulated and measured in X-band. The antenna bandwidth is increased by 94 % through simulation and 52 % experimentally with the use of metamaterial as a superstrate. The directive radiation pattern with narrow beamwidth is obtained with the use of metamaterial. The use of metamaterial superstrate enhances the peak gain of the antenna by 105 % through simulation and 103 % experimentally.

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

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. HEM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">21δ</sub> 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.

Bandwidth Enhancement of Circularly Polarized Dielectric Resonator Antenna

Axial-ratio (AR) bandwidth enhancement is achieved for a circularly polarized (CP) cylindrical dielectric resonator antenna (DRA) using a wideband hybrid coupler (WHC) combined with dual probe feed. The presented WHC, comprised of a Wilkinson power divider and a wideband 90° shifter, delivers good characteristics in terms of 3 dB power splitting and consistent 90° (±5°) phase shifting over a wide bandwidth. In turn, the proposed CP DRA, for the employment of the WHC, in place of conventional designs, provides a significant enhancement on AR bandwidth and impedance matching. The antenna prototype with the WHC exhibits a 3 dB AR bandwidth of 48.66%, an impedance bandwidth of 52.5% for voltage standing wave ratio (VSWR) ≤ 2, and a bandwidth of 44.66% for a gain of no less than 3 dBi. Experiments demonstrate that the proposed WHC is suitable for broadband CP DRA design.

원통형 삼중모드 유전체 공진기를 이용한 대역 통과 여파기의 설계

Abstract In this paper, the design of a compact triple-mode bandpass filter using a high-Q cylindrical dielectric resonator is proposed. In detail, the triple TE 01δ modes along three orthogonal axes are used and novel coupling structure in the metallic enclosure is adopted to introduce the coupling between the resonant modes. Due to the cross coupling, the proposed bandpass filter has an asymmetric frequency response with flexible three transmission zeros, one of which can be located very close to the passband edge to provide an extremely sharp skirt characteristic with low insertion loss. The proposed filter is about 60 % miniaturized compared with conventional single-mode dielectric resonator filter. The proposed bandpass filter design is validated by the circuit and 3D EM simulations and measurements compared to the target specifications.Key words: Triple-Mode, Dielectric Resonator, Filter, Miniaturization nopqr'st.uG@vopwx(ATC) yr0opW.R@zh{|(10035960).} (~)€‚'ƒopY(RD Revised November 4, 2014 ; Accepted December 22, 2014. (ID No. 20140924-03S)Corresponding Author: Geon-Ho Jang (e-mail: ghjang@kmw.co.kr)

Fabrication and Characterization of a W-Band Cylindrical Dielectric Resonator Antenna-Coupled Niobium Microbolometer

We report on the fabrication and characterization of a novel antenna-coupled detector configuration for detection at 94 GHz, a coplanar waveguide- (CPW-) fed, slot-excited twin dielectric resonator antenna- (DRA-) coupled niobium (Nb) microbolometer. The antenna is based on two low permittivity cylindrical dielectric resonators (CDRs) excited by rectangular slots placed below the CDRs. The antenna resonant currents are fed to an Nb microbolometer by the means of a CPW feed. The ceramic DRA structure is manufactured using a novel fabrication process that enables patterning an SU-8–Alumina (Al2O3) nanopowder composite using conventional photolithography. The detector measured a voltage responsivity of 0.181 V/W at a modulation frequency of 150 Hz. The detector measured a time constant of 1.94 μs. The antenna radiation pattern of the developed detector configuration was measured and shows a good agreement with the simulation.

MULTI-BAND CYLINDRICAL DIELECTRIC RESONATOR ANTENNA USING PERMITTIVITY VARIATION IN AZIMUTH DIRECTION

A novel multi-band cylindrical dielectric resonator antenna (CDRA) using microwave laminates with permittivity variation in azimuth direction fed by coaxial probe is proposed in this paper. The proposed structures are constructed using different materials having different permittivities in azimuth direction in cylindrical dielectric resonator (DR). In order to determine the performance of various design parameters on resonance frequency and bandwidth, parametric studies have been performed. The operating band can be scaled up or down by adjusting the design parameters. Dual- band and triple-band CDRAs have been fabricated using commercially available microwave laminates to validate the simulation results. For each case, the input reflection coefficient, radiation pattern and antenna gain are simulated and measured. Good agreement between simulated and measured results has been observed. The proposed antennas may be suitable for WLAN applications.

HYBRID BROADBAND 60-GHZ DOUBLE NEGATIVE METAMATERIAL HIGH GAIN ANTENNA

This paper proposes a double negative metamaterial surface as a superstrate for a multilayer cylindrical dielectric resonator antenna (MCDRA). The aim is to achieve a broadband and high gain Electromagnetic Band Gap (EBG) antenna that can be used in harsh propagation areas to satisfy all the requirements for the 60GHz wireless communications offering a bandwidth of 7GHz in the unlicensed ISM band (57–65 GHz), permitting to reach data rates of 10Gbit/s and more. To meet these objectives various techniques are combined. Numerical and experimental results showed satisfactory performances with achievable impedance bandwidth of more than 10.5% (from 58.1 to 64.2GHz) and a 18 dBi gain, an enhancement of 13 dBi compared to a homogenous DRA without metamaterial superstrate. The proposed antenna exhibits directive and stable radiation pattern in the entire operating band.

Embedded cylindrical magneto-hydrodynamic antenna

An antenna consisting of three concentric cylindrical dielectric resonator antenna (DRA) is placed on circular patch surrounded by two annular rings. This antenna is excited with feed probe. Cylindrical propylene pipe (PPR) tubes have been filled with a mixture of silicon oil and barium strontium titanate. The electric fields and magnetic fields produced fluid velocity field due to magneto-hydrodynamic (MHD) phenomenon. The fluid velocity v, becomes a function of poynting vector. By applying external variable DC electric bias (5 V to 30 V) using bias TEE in association with fixed magnetic bias (2,500 Tesla) in fluid resonators, antenna gain varied from 1.5 dB to 11.07 dB. Two permanent magnets are used to produce magnetic bias. The controlled frequency shift of 8.82 GHz, 10.5 GHz, 12.4 GHz and 12.7 GHz are observed with combinations of applied bias, which made this antenna frequency agile.

Nonresonant Microstrip Patch-Fed Dielectric Resonator Antenna Array

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.