Characteristics of dielectric ring resonator antenna with an airgap

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 TM_01δ 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     

A small dielectric resonator antenna

By covering a cylindrical dielectric resonator antenna with a metallic cap, the resonant frequency of the antenna can be reduced by 30.6%. The result finds applications in designing small antennas for wireless communication systems.     

Aperture-coupled dielectric resonator antenna with a perpendicularfeed

The aperture-coupled dielectric resonator antenna with perpendicular feed is investigated experimentally. The return loss, radiation pattern, and antenna gain of the new configurations are given and discussed     

Stacked annular ring dielectric resonator antenna excited byaxi-symmetric coaxial probe

A stacked annular ring dielectric resonator (DR) antenna composed of commercially available dielectric resonators and exited by axi-symmetric coaxial probe is studied computationally using the finite-difference time-domain (FDTD) method. The numerical results are checked against experimental measurements, and good agreement is observed. It is demonstrated that the introduction of air-gaps between the two DR's and also between the driven DR and the ground plane can improve the impedance bandwidth of the antenna significantly. The effects of the air-gaps thickness on the return loss and the bandwidth are discussed. The far-fields are also calculated by applying the electromagnetic field equivalence principle. The antenna produces an end-fire radiation field similar to that of an electric monopole     

Experimental investigation on new steerable dielectric resonator antenna

A new steerable-dielectric resonator antenna is described. It consists of a movable annulus of heterogeneous dielectric sections surrounding a cylindrical core of another dielectric. The antenna far-field radiation was found to be manipulated by changing the angular position of this ring. This antenna demonstrates resonance at ~1.2 GHz with a fractional bandwidth of 28.3% (Sn₁₁< - 10 dB), confirming an HFSS simulation of the same structure.     

Rectangular dielectric resonator antenna

An antenna which consists of a resonant rectangular parallelepiped dielectric on top of a ground plane is described. Calculated radiation patterns and measured impedances are presented, and the effects of feed probe length variations are discussed.     

An X-band dielectric resonator antenna using a single elliptical shaped dielectric resonator

This paper presents design evolution of a single elliptical dielectric resonator antenna to achieve wide measured impedance band-width extending from 8.26 GHz to 12.15 GHz. Design evolved from a right circular cylindrical DRA by varying the dimension along the semi-minor axis and thereby resulting in an elliptical DRA that supports near similar field distribution over the X-band. This similar field variation is achieved by tuning the eccentricity of the elliptical geometry, the feed position as well as height of the DRA. A fabricated prototype is developed and measured results agree well with that obtained from simulation. Apart from wide impedance bandwidth, the observed pattern bandwidth is also similar.     

A monopole antenna loaded by a hemispherical dielectric resonator

The input conductance, radiation pattern, and radar cross section (RCS) of a monopole loaded by a hemispherical dielectric resonator (DR) are studied. The effects of the DR on the monopole characteristics are investigated. Measurements were carried out to verify the theory. It is found that the input conductance, radiation patterns, and RCS are strongly affected by the DR.     

一种新型X波段超宽带介质谐振器天线的设计

设计了一种新型的超宽带介质谐振器天线。该天线采用微带-槽耦合馈电方式,通过在地板上开矩形槽,背面由50Ω的微带线中心馈电,从而展宽带宽。采用类似T型层叠结构,产生两种频率相近的模式,从而显著提高天线的阻抗带宽。仿真结果显示,该新型超宽带介质谐振器天线工作于X波段,天线的相对阻抗带宽达到47.37%,频段内平均增益超过7.2 d Bi,天线方向图对称性良好。天线的整体辐射特性良好,且结构简单,易于实现,可应用在微波通信、雷达等领域。     

Aperture coupled dielectric resonator antenna with a thick groundplane

The aperture-coupled hemispherical dielectric resonator antenna with a thick ground plane is investigated theoretically and experimentally. The effects of the ground plane thickness on the input impedance, resonant frequency, and front-to-back radiation ratio are studied     

Circularly polarised dielectric resonator antenna with metallicstrip

A new design of circularly polarised slot fed dielectric resonator antenna (DRA) is presented. The dissymmetry of the design enabling circular polarisation relies on a metallic strip printed on top of the resonator. Simulations are compared with measurements for a single antenna as well as a four DRA sequential rotation array     

Conical steerable dielectric resonator antenna

A conical steerable dielectric resonator antenna is presented and analysed using an in-house developed FDTD simulator. A 30% impedance bandwidth is achieved with an average gain of 6.5 dBi. Radiation patterns in the principal planes do not change significantly within the impedance bandwidth, presenting more than 18 dB frontto- back ratio in the azimuthal plane.     

Quasi-TEM rectangular dielectric resonator antenna

A new rectangular dielectric resonator antenna is presented. The dielectric resonator is caught between two metallic plates. As a result, the structure works in a quasi-TEM mode. The proposed antenna exhibits a 22% impedance bandwidth and good radiating characteristics.     

Switchable cylindrical dielectric resonator antenna

A switchable cylindrical dielectric resonator antenna operating in four different radiation modes is reported. Two linear polarised, one circular polarised, and a nonradiating mode are implemented. The experimental results of the resonant frequency, boresight axial ratio, gain, unloaded Q-factor, impedance bandwidth and radiation efficiency are presented for the operating modes and compared with the theoretical values     

Annular slot-coupled dielectric resonator antenna

An annular slot-coupled dielectric resonator antenna is investigated experimentally. As compared with the previous rectangular-slot version, the new configuration offers a much wider bandwidth of 18%. The return loss, radiation patterns, and antenna gain of the configuration have been measured and are discussed     

Leaky-mode cylindrical dielectric resonator antenna

A cylindrical dielectric resonator (CDR) antenna, operating in leaky TM-modes, is presented. The antenna is composed of the CDR, short-circuited by parallel rectangular conducting plates. The radiation pattern depends on the size and shape of conducting plates. This technique provides an opportunity to change the radiation pattern without affecting antenna resonant frequency. Numerical examples based on the integral equation method are presented to show advantages of this design     

Adjustable frequency dielectric resonator antenna

An easy method of tuning the resonant frequency of cylindrical and ring dielectric resonator (DR) antennas using different diameters of conducting plates is presented. This technique can tune a DR antenna to operate at the design frequency without changing antenna performance. The maximum frequency tuning range can reach up to 300-500 MHz     

Excitation of dielectric resonator antenna using a soldered-throughprobe

A soldered-through probe is used to excite the dielectric resonator antenna (DRA). A cylindrical ring DRA is used to demonstrate the feasibility of this excitation method. The return loss, radiation pattern, and antenna gain of the new configuration are studied     

Coplanar-waveguide-fed slot-coupled rectangular dielectric resonator antenna

A novel coupling scheme to a rectangular dielectric resonator antenna is proposed and investigated. In particular, coupling to the resonator is achieved through a narrow slot at the end of a coplanar waveguide (CPW). The objectives of this design are to maximize the coupling, match the dielectric resonator to the CPW feed line, achieve resonance at the desired frequency, obtain linear polarization with low cross polarization components, and minimize back radiation without using a back conductor. An approximate and quick design approach is given followed by more accurate design and analysis using commercial software. The antenna was fabricated and tested. Measurements match well with simulation results.     

Circular polarised cylindrical dielectric resonator antenna

A circular polarised cylindrical dielectric resonator antenna excited using a simple microstrip feed line is reported. The experimental results of the resonant frequency, radiation pattern, boresight axial ratio, gain, unloaded Q-factor, impedance bandwidth and radiation efficiency are presented