TM01δ Mode Research Articles

A low profile high gain concave conformal ring cylindrical dielectric resonator antenna loaded with split ring resonator for ISM and C band applications

SummaryA low profile, concave conformal ring cylindrical dielectric resonator antenna (CDRA) employing frequency selective surface (FSS) using split ring resonator (SRR) for wideband and high gain applications is presented. The ring CDRA loaded with the monopole is designed to excite the TM01δ mode to increase the antenna's bandwidth. The effect of a curved ground plane (GP) on the radiation performance of CDRA is studied. A 5 × 5 array of the SRR is placed above the conformal GP at a far‐field distance optimized to (2n ± 1) λ/4 from the radiating element to enhance the gain of the proposed structure. The planar CDRA with FSS is compared with the conformal CDRA with FSS and a 4.3 GHz improvement in bandwidth is observed due to the multiple reflection and surface reflection leading to a 3.2 dBi improvement in gain. An impedance bandwidth of 51.8% (5 to 8.5 GHz) with a maximum gain of 8.7 dBi at 7.3 GHz resonant frequency and 99% radiation efficiency at 5.9 GHz is offered by the proposed antenna with FSS. Additionally, the proposed CDRA has a low profile of 0.12 λ0 where λ0 is the lower cut‐off frequency's wavelength. A good agreement is observed between the simulated and measured results.

A pattern reconfigurable graphene-based Yagi-Uda antenna with TM01δ mode generation for THz applications

A pattern reconfigurable graphene-based Yagi-Uda antenna with TM01δ mode generation for THz applications

A Low-Profile Cylindrical Dielectric Resonator Antenna with Bandwidth-Enhancement under Triple-Mode Resonance

A low-profile cylindrical dielectric resonator antenna (CDRA) with enhanced impedance bandwidth is proposed via sharing a single triple-mode dielectric resonator. Initially, the resonant frequencies of TM 01δ and TM 02δ modes of a conventional CDRA are maintained far away from each other under central probe feed. Next, a circular disk with an annular ring is loaded around the conventional CDRA, aiming to excite an additional mode between these dual modes. The electric fields demonstrate that the previous TM 02δ mode is transformed into the TM 03δ mode for the modified CDRA, and an additional TM 02δ mode is successfully excited between the TM 01δ and TM 03δ modes. As a result, the resonant frequencies of these three radiative modes are reallocated in proximity to each other, thus achieving the desired bandwidth enhancement. In addition, considering the small input impedance of the CDRA, a microstrip feeding line is introduced underneath the central probe for good impedance matching. With these arrangements, the resultant antenna can generate an extended bandwidth under simultaneous radiation of TM 01δ , TM 02δ , and TM 03δ modes. Finally, the proposed CDRA is designed, fabricated, and measured to validate the predicted performance. The simulated and measured results show that the impedance bandwidth (|S 11 | < −10 dB of the antenna is dramatically extended from 8% to about 62% (2.83∼5.36 GHz), while keeping a stable conical radiation pattern. In particular, a low profile property of about 0.15 free space wavelength is achieved as well.

Performance Estimation of Cylindrical Dielectric Resonant Antenna

This paper discusses the design and implementation of a cylindrical dielectric resonator antenna which is excited with HEM11δ as dominant mode using surface coaxial probe feed technique. The designed antenna radiates in the HEM11δ mode with a wide impedance bandwidth of over 2 GHz, and with a maximum gain of 5.93 dB thereby improving both gain and bandwidth compared to conventional micro strip patches. Further compared the characteristics of TE01δ and TM01δ modes with that of HEM11δ mode to prove the better radiation characteristics of the mode. By the proper selection of the parameter’s antenna radiates in the entire C-band with a resonating frequency of 5.1 GHz. The designed antenna meets all the common features of the DRAs, but the main advantage is its ability to resonate with a considerably low- permittivity dielectric material.

Compact Cylindrical Pattern-Diversity Dielectric Resonator Antenna

A compact cylindrical pattern-diversity dielectric resonator antenna (DRA) is designed using the HEM11δ and TM01δ modes, which are the fundamental modes of the hybrid electromagnetic (HEM) and TM modes, respectively. To make the two resonance frequencies equal for the diversity operation, a meander-line-loaded annular slot is used to excite the TM01δ mode and to lower its resonance frequency. The annular slot, however, does not significantly affect the HEM11δ mode, which is excited by a pair of differential strips. It is found that impedance match of each port can be tuned independently. To verify the idea, a 2.4 GHz prototype was designed, fabricated, and measured for WLAN applications. Good agreement between the measured and simulated results is observed. The impedance passbands of the two modes have an overlapping bandwidth of 5.7%, with the port isolation higher than 30 dB. The envelope correlation coefficient obtained from the measured field patterns is desirably very low, being less than 0.001. Our design is electrically smallest in volume and lowest in profile among the reported pattern-diversity DRAs.

Rapid Characterization of Powder Mixtures through High Q Dielectric Resonator

In this research work a high quality factor cylindrical dielectric resonator is used to determine the dielectric properties of powder mixtures. The setup is based on resonant perturbation theory and it has a potential to quickly and accurately characterize samples in quantities as small as a tens of milligrams. The loaded quality factor of the proposed dielectric resonator is 19,217, which is operated in TM01δ mode at 10.57 GHz. The measured results are compared with the calculated values obtained from different mixing models. The worst case measured dielectric constant error of 9.4% and 9.95% has been observed for mixtures of boric acid – titanium dioxide and baking soda – titanium dioxide respectively with variable concentrations of weight. The proposed technique is suitable to be deployed in industries in order to rapidly assess the mixture concentration before subjected to the detail investigation.

Cylindrical Dielectric Resonator Antenna Excited by a Composite Feed to Generate Monopole Like Radiation Characteristics

In this paper, a monopole like single segment cylindrical dielectric resonator antenna (CDRA) with a composite feed (probe with microstrip patch feed) configuration is described. The antenna consists of liquid phase (3 wt.% 45Bi2O3-55B2O3 glass) sintered Ba0.5Sr0.5TiO3 dielectric ceramic (BST-BB3) having dielectric constant (er) of 17 as a radiating element of CDRA. 3 wt.% 45Bi2O3-55B2O3 glass reduces the sintering temperature of Ba0.5Sr0.5TiO3 from 1250°C to 950°C without affecting the crystal structure and thereby reduces the manufacturing cost of the ceramic material. Three different feed configurations i.e. probe connected to plus-shaped patch (PPP), probe connected to swastika-shaped patch (PSP) and PXP [probe connected to XOR-shaped patch] are proposed. The simulated field distributions show that TM01δ, TE01δ and distorted TM01δ modes are excited as dominant modes in PPP-, PSP-, and PXP-fed CDRA respectively. The simulated − 10 dB reflection coefficient bandwidths of the CDRA excited by three different feed configurations are compared. CDRA with PXP feed (proposed antenna) provides largest − 10 dB reflection coefficient bandwidth of 40.77% (7.44–11.25 GHz) with resonant frequency of 7.78 GHz. The experimental − 10 dB reflection coefficient bandwidth of the proposed antenna is found to be 52.08% (7.03–11.98 GHz) with resonant frequency of 8.30 GHz. The proposed antenna provides monopole like stable radiation patterns which get distorted towards higher frequency side of the operating frequency band. The experimental reflection coefficient–frequency characteristic as well as radiation characteristics of the proposed antenna are nearly in agreement with the corresponding simulated characteristics. The proposed antenna can find potential application in radar and communication.

A Wide-Band Wide-Beam Dielectric Resonator Antenna

Background: A wide-band wide-beam Dielectric Resonator Antenna (DRA) is proposed in this paper. Methods: A cylindrical dielectric resonator operating in TM01δ mode is placed on a hybrid-structure ground which consists of a corner-reflector and a pentagon plate with edge-fold. With this structure, wide-band wide-beam characteristics can be achieved. Results: From simulation results, the impedance bandwidth (|S11|< -10 dB) of the antenna is from 1.8 to 3.14 GHz. The radiation pattern is stable, and the 3dB beam-width of H-plane is larger than 160° over the impedance bandwidth. Conclusion: A prototype of the proposed antenna is fabricated and tested, and the testing results are in agreement with the simulation. Keywords: DRA, wide-beam, wide-band, design process, dielectric resonator, antenna.

Low‐profile circularly polarized cylindrical dielectric resonator antenna coupled by L‐shaped resonating slot

ABSTRACTThe aim of this work is to design a low‐profile Circularly Polarized Dielectric Resonator Antenna for the X‐band frequency applications. With optimized design the proposed Cylindrical DRA (CDRA) fed by off‐centered L shaped slot is showing characteristics of Circular Polarization in the proposed band. Two orthogonal arms of off‐centered L shaped slot having different dimension excite the two TM01δ modes at 9.5 and 10.5 GHz, in addition both slots itself produce resonances nearly at 8.6 GHz. Combination of all these resonances is generating the nature of circular polarization near 9.5 GHz. Parametric study on designed antenna has been done in order to determine the effect of design parameters on the circular polarization. Axial Ratio bandwidth of 10.5% (1 GHz) and impedance bandwidth of 25% (2.3 GHz) at 9.5 GHz has been shown for single and simple feed low‐profile CDRA. Prototype of optimized design has been fabricated for the validation and measured results have shown good agreement with simulated ones. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:996–1000, 2017

Top loaded TM01δ Mode Cylindrical Dielectric Resonator for Complex Permittivity Characterization of Liquids

Top loaded TM01δ Mode Cylindrical Dielectric Resonator for Complex Permittivity Characterization of Liquids

Segmented quarter cylindrical dielectric resonator antenna: simulation and experimental investigation in composite form for wideband applications

A probe feed wideband multi-element dual segments quarter cylindrical dielectric resonator antenna (q-CDRA) in composite forms have been proposed. The q-CDRA has been introduced by splitting CDRA into four uniform quarters and multi-segmentation approach has been castoff for further improvement in bandwidth of q-CDRA. The dual segments q-CDRA has been designed and analyzed using theoretical analysis and Ansoft HFSS simulation software. Further the dual segment multi-element q-CDRAs in composite form have been designed. A coaxial probe has been placed at the center of the ground plane for the excitation of proposed multi-element and multi-segmented composite form of q-CDRA, which excite TM01δ mode in the proposed antenna. The input characteristics and radiation patterns of the proposed composite antennas have been studied and their results are compared with corresponding experimental results. Prototype of single, two, and four elements dual-segment composite q-CDRAs have been fabricated and input characteristics of the proposed composite antennas have been compared with each other. Four elements dual-segment composite q-CDRA has shown wide impedance bandwidth (|S11| ≤ −10 dB) of 85.13% with monopole-like radiation pattern. The peak gain of 4.85 dBi with 98.5% radiation efficiency has been achieved for dual-segment four elements composite q-CDRA. The proposed multi-element dual-segment composite q-CDRAs may find suitable applications in C and X-band with complete covering of the 5.0 GHZ wireless local area network (WLAN) and worldwide interoperability for microwave access (WiMAX) band.

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.

Three‐element multilayer multipermittivity cylindrical dielectric resonator antenna for wideband applications with omnidirectional radiation pattern and low cross‐polarization

AbstractIn this article, a three‐element multilayer multipermittivity (MLMP) cylindrical dielectric resonator antenna (CDRA) is proposed for wideband application. This MLMP CDRA is excited with central MLMP CDR using coaxial probe excitation above the finite ground plane. The central MLMP CDR is located at the center of three‐element MLMP CDRA arrangement. The TM01δ mode is excited in central MLMP CDR using coaxial probe, and hence, HE11δ mode would be excited in each MLMP CDRA element. The proposed three‐element MLMP CDRA provides the measured impedance bandwidth of 52.9% (at resonance frequency of 4.42 GHz) from 3.88 to 6.22 GHz for reflection coefficient (S11) less than −10dB with omnidirectional radiation pattern and low cross‐polarization. The average gain of proposed antenna is 5.70 dB in the frequency range of 3.88–6.22 GHz. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2011–2016, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26985

Omnidirectional Cylindrical Dielectric Resonator Antenna With Dual Polarization

This letter proposes an annular cylindrical dielectric resonator antenna (DRA) with two-port diversity realizing simultaneously omnidirectional horizontally and vertically polarized radiation patterns with low cross coupling. The horizontally and vertically polarized radiation patterns are achieved by exciting the orthogonal TE01δ and TM01δ modes in a single cylindrical dielectric resonator (DR). Due to the high Q-factor of the TE01δ mode, an air gap and multiple feeding lines are introduced to increase the impedance bandwidth. The proposed antenna provides an impedance bandwidth of 19.1% in the vertically polarized mode and an overlapping bandwidth of 7.4% in the horizontally polarized mode, with the overlapping band ranging from 3.78 to 4.07 GHz. Antenna diversity and multiple-input-multiple-output (MIMO) performance are examined in terms of envelope correlation coefficient and mean effective gain.

Interresonator coupling between two TM01? mode cylindrical dielectric resonators

An analytical technique for the determination of interresonator coupling between two axially placed TM01δ mode dielectric resonators in a suspended substrate environment is presented in this paper. The analytical formulation is based on the induction concept and capacitive coupling between the two resonators. Numerical results have been validated with the available published data. © 1998 John Wiley & Sons, Inc. Microwave Opt Technol Lett 19: 210–213, 1998.

Cavity-restrained multistacked dielectricomnidirectional antenna for microwave andmillimetre-wave wireless communications

A novel microwave omnidirectional antenna is proposed for wireless communications. This antenna is constructed with cavity-restrained multistacked dielectric discs. Vertical polarised omnidirectional radiation patterns are obtained from radiative ring slots in the side wall of dielectric-metal cavities operating in the TM01δ mode. High omnidirectional gain is realised with stacked cavities with multiradiative slots. Ring slots between the adjacent cavities are used to ensure the excitation of the desired radiating mode in phase, which actually eliminates the feed network. A special technique is adopted for excitation of the antenna from the coaxial line, with which very good matching is achieved.

Characteristics of dielectric ring resonator antennawith an air gap

The characteristics of centre probe-fed cylindrical dielectric ring resonator antennas with an air gap are studied both theoretically and experimentally. The return loss of the TM01δ mode is evaluated by using the finite-difference time-domain (FDTD) method and the result agrees well with the measured data. It is demonstrated that the impedance bandwidth can be improved by adjusting the air-gap spacing.