A Cylindrical Dielectric Resonator Antenna with Nested Structure

Dielectric resonators (DR) find application in the design of microwave antennas. The radiation patterns of DR antennas are related to their excited resonant model(s). Dielectric resonators of low dielectric constant are usually employed to give a reasonable impedance bandwidth. We demonstrate that the bandwidth of a center probe-fed cylindrical dielectric ring resonator antenna can be increased by stacking another DR of the same dimensions on the top of the fed DR. The return loss and the radiation patterns of the stacked DR antenna are computed using the finite difference time-domain (FD-TD) method. The numerical results so obtained are compared to experimental measurements. >

The eigenmode expansion method is used to evaluate the resonant frequency of a probe fed cylindrical dielectric resonator (DR) antenna, which radiates above an infinite conducting ground plane. A parallel grounded conducting plane is added above the DR, thus allowing the use of cylindrical harmonic field expansions in the regions between the two parallel ground planes. The eigenmode expansion coefficients are found by enforcing the boundary conditions at conducting surfaces and regional interfaces. Then, from the induced currents on the probe surface, the input impedance and the resonant frequency of the DR antenna are evaluated. The results are compared with those of a previous configuration which has no upper ground plane. It is found that the deviation of the calculated resonant frequency is less than 2% for epsilon εr>9.

A new excitation method using a solder-through probe is used to excite the cylindrical ring dielectric resonator antenna (DRA). The return loss, radiation pattern and antenna gain are studied experimentally. A simple formula for estimation of the TM/sub 01/spl delta// mode resonant frequency of the DRA is presented.

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.

A compact dual band cylindrical dielectric resonator antenna (CDRA) is designed and presented. The CDRA is excited by E-shaped aperture, which is located below the microstrip line feed on the ground plane. The defected ground plane has a conducting strip under the Dielectric Resonator Antenna (DRA) that causes the upper resonance at 5 GHz. The lower band at 2.45 GHz is achieved by applying a metallic top-loaded cylindrical dielectric antenna (CDRA). The experimental results show the antenna covers 2.45 GHz and 5 GHz with −10dB return loss, satisfying the desired standards of WLAN applications.

A Microwave band pass filter employing dielectric ceramic ring resonator is designed, fabricated and tested. Band pass filter characteristics are studied by measuring the return loss and transmission characteristics of the microstrip line fed dielectric ring resonator. S-parameters, electric field and magnetic field distributions are computed using FEM method and compared with measured results. The measured values agree with predicted values obtained using FEM. Centered at 2404 MHz the fabricated dielectric ring resonator filter shows a measured 3-dB band width of 20.6 MHz.

In this paper, a slot coupled wideband circularly polarized cylindrical ring dielectric resonator antenna (DRA) has been presented. Circular polarization in DRA is generated using slot coupling excited with microstrip feed. Proposed design antenna shows −10 dB input impedance bandwidth of 13.15% and in broadside direction 3-dB axial ratio bandwidth of 10.00%. In addition, proposed antenna shows HEM 12δ mode, stable gain, radiation efficiency and offers right hand circular polarization.

This paper presents a multiple input multiple output (MIMO) system for sub-6 GHz using a two-port cylindrical dielectric resonator (CDR). This band is ideal for 5G applications, providing a balanced combination of coverage and capacity, as well as offering high data rates and low latency. The proposed MIMO is excited by an aperture-coupled feed structure composed of driven elements consisting of an elliptical-shaped step impedance transform line to enhance CDR coupling. Aperture coupling is used to excite the HEM 11δ mode without the involvement of any hybrid mode. The purpose of the aperture coupling in the CDR antenna is to launch the HEM 11δ mode, which is a magnetic dipole that provides a stable radiation pattern in the 3.2–3.7 GHz band, allowing for efficient transmission and reception of the data. Symmetrically oriented CDR and the presence of orthogonal fields provide good isolation, which can be further improved by the insertion of an asymmetric cross slot. The designed CDR-based MIMO antenna achieves excellent isolation of over 20 dB and demonstrates improved envelope correlation coefficient (ECC) values, resulting from low field correlation, across the entire frequency band of operation. Almost all the major diversity analysis was carried out for the desired sub-6 GHz band while maintaining a relatively compact size. Based on the measured results, it is confirmed that the proposed CDR-based MIMO antenna is appropriate for sub-6 GHz applications.

Cylindrical and conical ultra-wideband (UWB) dielectric resonator antennas are presented in this paper. The first part of this work is a parametric study of cylindrical and conical dielectric resonator antennas for Ultra-Large Band applications ranging from 3.1GHz to 10.6GHz. The second part of the work consists of creating a reconfigurable rejection band inside this UWB in order to minimize interference between UWB system and some narrowband systems operating in this frequency range (3.1GHz to 10.6GHz), Such as WiMAX and WLAN. To obtain the rejection band, we etch a rectangular ring slot on the micro-strip-line-fed patch. The control of the band notch is made by displacing the cylindrical or the conical resonator. The results obtained showed that the band notch ranges from 3.2GHz to 4.7GHz for the cylindrical resonator and from 3.2GHz to 5.2GHz for the conical resonator. The proposed structures are simulated with the commercial electromagnetic simulation software “Ansoft HFSS.” The numerical results from different simulations are presented in terms of reflection coefficient and radiation pattern.

In this paper, a Coaxial probe-fed Laterally placed Cylindrical Dielectric Resonator Antenna (LCDRA) with symmetrical triangular notches is presented. The lateral surface of the Cylindrical Dielectric Resonator Antenna (CDRA) is kept on the ground plane with its longitudinal axis parallel to the ground plane. LCDRA has a lower resonant frequency than the CDRA and it offers considerably wider impedance bandwidth than CDRA. Finally, two symmetrical triangular notches are introduced on the two edges of LCDRA which is perpendicular to the axis to further improve the impedance bandwidth. The proposed antenna offers a wide impedance bandwidth (

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.

Communication of present era involves Wi-Fi, Wimax and WLAN. Proposed antenna is designed keeping in mind for these particular requirements. Narrow beam may impart large amount of gain for one particular communication requirements. This paper investigates cylindrical dielectric resonator antenna with introducing band gap structure on the circular patch of DRA for imparting high gain. The application of this antenna can had in the field of WLAN. In this paper characteristics of cylindrical Dielectric Resonator Antenna (DRA) using BaZrO3 (er=27) material, are studied. The DRA antenna is designed by using HFSS software which employs the FDTD method for solution. The characteristics of these antennas are investigated with both co-axial feeding and used for exciting the DRA. The experiment is performed on cylindrical DRA shape fed by coaxial and BaZrO3 material of dielectric constant 27.

A new high‐gain cylindrical dielectric resonator antenna (DRA) with a large bandwidth is proposed. A cylindrical dielectric resonator, an intermediate layer and a metallic cylinder are used to obtain a large bandwidth and a high gain. The intermediate layer structure can suppress surface wave propagation, which results in a gain improvement, and the cavity formed by the metallic cylinder provides a further higher gain. The measured results demonstrate that the proposed DRA achieves a large bandwidth of 23% from 5.4 to 6.8 GHz with a voltage standing wave ratio of &lt; 2 and a high gain of around 11 dBi.

Design and analysis of stacked cylindrical dielectric resonator antenna (CDRA) with partial ground plane for ultra-wideband applications is examined. Ultra wide band has been achieved with the help of stacking of CDRA, mode conversion in CDRA and higher order mode generation in annular shaped printed line. The proposed design covers the frequency range of 3.55–10.78 GHz with a fractional bandwidth of 100.9% that satisfies the bandwidth requirement of UWB applications.

In this article, the design and analysis of a double cylindrical dielectric resonator antenna (CDRA) of compact size 40 × 40 mm2 with extended wideband characteristics for C- and X-band applications is presented. A couple of CDRA is placed over the two adjoin rectangular slots which are excited by a modified microstrip feed line of 50 Ω. The proposed double CDRA resonates between frequency band 4.75 and14.43 GHz with 100.93% (9.68 GHz) impedance bandwidth. Two adjoin rectangularslots with a modified microstrip feed line generate two orthogonal degenerated hybrid modes (HEMx 11δ and HEMy 11δ), which are liable for the creation of circular polarization characteristics between the frequency band 6.62 and 8.5 GHz with 24.86% (1.88 GHz) 3-dB axial ratio bandwidth. The stable peak gain of 6.27 dB at frequency 12.62 GHz, whereas the gain of 3.31–6.27 dB and radiation efficiency of more than 86% in the entire operating band is obtained.