Design Of Dielectric Resonator Antenna Research Articles

이중공진을 사용한 적층기판용 광대역 안테나 설계

In this paper, bandwidth enhanced design of dielectric resonator antenna fabricated in multi-layer substrate is introduced. The proposed dielectric resonator antenna is operating with fundamental TE101 mode and higher-order TM111 mode. Each resonance frequency is dependent on resonator dimensions. As increasing the height of radiating aperture, the higher-order TM111 mode resonance frequency approach the fundamental TE101 mode resonance frequency and the antenna bandwidth increase by double resonance. Three different aperture height size antennas that operated at 7㎓ are fabricated in FR4 multi-layer substrate. Measured 10 ㏈ matching bandwidth is 8 percent for single resonace antenna and 18 percent for double resonance antenna.

BANDWIDTH ENHANCEMENT AND MINIATURIZATION OF DIELECTRIC RESONATOR ANTENNA FOR 5.8 GHZ WLAN

This paper presents the design of Dielectric Resonator Antenna (DRA) operating at 5.8 GHz, using the techniques of Two Segments DRA (TSDRA) and High-Aspect Ratio Structure. The aim of the paper is to reduce the size of the DRA while still maintaining its large impedance bandwidth. The requirements for WLAN applications are carefully taken into considerations in the design of the proposed structure. Comparison has been made between the proposed design and single layer DRA (SLDRA); and it has been found that the former has better performances than the latter.

Microwave dielectric properties of 0.95MgTiO3–0.05CaTiO3 for application in dielectric resonator antenna

In this paper, the microwave dielectric properties of 0.95MgTiO 3 –0.05CaTiO 3 ceramics have been studied for application in dielectric resonator antenna design. ZnO was selected as liquid sintering aids to lower the sintering temperature of 0.95MgTiO 3 –0.05CaTiO 3 . The X-ray diffraction pattern exhibited single phase for ceramics up to 1.0 wt.%. The maximum dielectric constant was obtained for samples after 0.25 wt.% ZnO addition and 1290 °C for 4 h sintering. A near-zero temperature coefficient of resonant frequency ( τ f ) of −4.9 ppm/°C was obtained for 0.95MgTiO 3 –0.05CaTiO 3 ceramics with 0.25 wt.% ZnO sintered at 1250 °C for 4 h. The dielectric resonator antenna measured at 9.58 GHz exhibited a 5.92% bandwidth (return loss <−10 dB) of center frequency.

H-Shaped Dielectric Resonator Antenna for Wideband Applications

A novel dielectric resonator antenna design is presented for wideband applications in this letter. By using a dielectric resonator with an optimized H-shaped across section and an optimized trapezoidal patch adhered on the concave surface of the resonator as a feeding mechanism, an impedance bandwidth of about 62% (for VSWR les 2) , covering the frequency range of 3.6-6.85 GHz, is achieved. The measured results in terms of bandwidth and radiation pattern agree well with the simulated ones, confirming the theoretical design.

Cross-T-shaped dielectric resonator antenna for wideband applications

A new dielectric resonator antenna (DRA) is introduced for wideband applications, where the wideband of this DRA design comes from three factors: a compact cross-T-shaped dielectric resonator, a conformal inverted-trapezoid patch as a feed mechanism, and a copper-clad substrate as a baseboard. Measured results demonstrate that the proposed DRA achieves an impedance bandwidth of about 71.8% for VSWR≤2, covering a frequency range from 3.56 to 7.57 GHz. This antenna also provides a stable broadside radiation pattern and a gain range of 3.2–7.3 dBi across the operating bandwidth.

Multi-disciplinary Multi-objective Topology Optimization of Electromagnetics and Structural Mechanics (For Case of Optimal Dielectric Resonator Antenna Designs)

The designs of on-board electronic devices used in automobiles need to satisfy not only electronic requirements but also physical requirements such maintaining sufficient stiffness under loads. The development of multi-disciplinary optimization methods that also handle multi-physics issues can facilitate a systematic approach to the design of such devices. In this study, we propose a new multi-disciplinary topology optimization method that handles multi-physics phenomena, namely, the coupling of electromagnetic wave propagation problems with static structural mechanics problems. The Finite Difference-Time Domain method is used to solve the electromagnetic wave propagation problem, while the static structural mechanics problem is solved using the Finite Element Method. New relaxation schemes for the design domain and design variable settings are proposed to deal with the use of the different numerical methods. The integral reflection electric energy and the mean compliance are formulated as objective functions to be minimized in an optimization problem. A multi-objective function is also formulated based on a weighted sum formulation to deal with the two objective functions. The optimization algorithm is constructed based on sequential linear program-ming. A design example of a multiple-band dielectric resonator antenna is provided to show the usefulness of the proposed method.

The slot-coupled hemispherical dielectric resonator antenna with a parasitic patch: applications to the circularly polarized antenna and wide-band antenna

The aperture-coupled hemispherical dielectric resonator antenna (DRA) with a parasitic patch is studied rigorously. Using the Green's function approach, integral equations for the unknown patch and slot currents are formulated and solved using the method of moments. The theory is utilized to design a circularly polarized (CP) DRA and a wide-band linearly polarized (LP) DRA. In the former, the CP frequency and axial ratio (AR) can easily be controlled by the patch location and patch size, respectively, with the impedance matched by varying the slot length and microstrip stub length. It is important that the AR will not be affected when the input impedance is tuned, and the CP design is therefore greatly facilitated. For the wide-band LP antenna, a maximum bandwidth of 22% can be obtained, which is much wider than the previous bandwidth of 7.5% with no parasitic patches. Finally, the frequency-tuning characteristics of the proposed antenna are discussed. Since the parasitic patch can be applied to any DRAs, the method will find applications in practical DRA designs.

Complex resonance and radiation of hemispherical dielectric-resonator antenna with a concentric conductor

The probe-fed hemispherical dielectric-resonator antenna (DRA) with a concentric conductor is studied theoretically in this paper. Using the mode-matching method, the exact Green's functions for evaluation of the input impedance and radiation patterns are found, with the functions presented in computationally efficient forms. The moment method is used to determine the probe current and, hence, the input impedance as well as the radiation patterns. The results are verified by special cases available in the literature. In this paper, the effects of the conductor radius, dielectric constant, probe length, and probe displacement on the input impedance are investigated. The theory is very general and, by taking appropriate limits, can be used to study the solid DRA and the conductor-loaded wire antenna. To aid the DRA design engineer, the TE/sub 111/-mode characteristic equation of the DRA is also studied, from which the simple formulas for the resonant frequency and Q-factor are obtained.

Robust slot-fed dielectric resonator antenna using an intermediate substrate

A new slot-fed rectangular dielectric resonator antenna design is presented. An intermediate substrate is introduced between the slot and the resonator, resulting in a correct excitation of the fundamental mode and a particularly robust structure to adhesive thickness. Comparisons between finite difference time-domain simulations and measurements confirm the good properties of the proposed design.

Half volume dielectric resonator antenna designs

The authors demonstrate that the volume of a conventional dielectric resonator antenna (DRA) can be reduced by approximately half. The technique relies on employing an additional conducting plate in the DRA, which acts as an electric wall. Experimental and simulation results are provided for cylindrical and rectangular dielectric resonator antenna designs.