Low profile equilateral-triangular dielectric resonator antenna ofvery high permittivity

An aperture-coupled equilateral-triangular dielectric resonator antenna (DRA) of very high permittivity (ϵ_r=82) is investigated experimentally. The triangular DRA is more compact in size than rectangular and circular disk DRAs operating at the same frequency. The impedance matching, radiation patterns and antenna gain of the triangular DRA are presented     

Embedded dielectric resonator antenna for bandwidth enhancement

A new embedded structure with an annular ring and a cylindrical dielectric resonator excited by means of a coaxial probe has been realised and investigated experimentally to obtain a large bandwidth enhancement. The return loss, radiation patterns, and antenna gain of this configuration are presented. The capability of such an antenna, with a low profile (a/h=6) and 10 dB impedance bandwidths of 32 and 38%, is demonstrated     

Offset dual-disk dielectric resonator antenna of very highpermittivity

An aperture-coupled offset dual-disk dielectric resonator antenna of very high permittivity is investigated experimentally. It is found that the new configuration offers an impedance bandwidth 4.6 times wider than that of the single element. The voltage standing wave ratio, radiation patterns, and antenna gain of the configuration are studied     

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.     

Low-profile circular disk DR antenna of very high permittivityexcited by a microstripline

A microstripline-fed dielectric resonator (DR) antenna disk of very high permittivity is investigated experimentally. The configuration has the advantage of being low-profile and allows the ground plane to be arbitrarily thick for mechanical support and/or heatsink purposes. The return loss, radiation patterns, and antenna gain of the configuration are studied and compared with those of the aperture-coupled version     

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.     

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     

Dual-polarised dielectric resonator antenna with high isolation and low cross-polarisation

A novel, dual-polarised dielectric resonator antenna with high-isolation and low cross-polarisation is presented using a hybrid feeding technique. Port isolation of 35.9 dB and a cross-polarisation level of 234 dB are measured. The impedance bandwidth of return loss less than 210 dB is 440 MHz (7.9%) with a centre frequency of 5.7 GHz. Since its feeding mechanism is symmetric, a symmetric radiation pattern is also achieved. It is suitable for the application of synthesis aperture radar and some wireless systems.     

Circular-polarised dielectric resonator antenna excited by dualconformal strips

A circular-polarised cylindrical dielectric resonator antenna excited by dual conformal strips is investigated experimentally. The configuration offers a wide axial-ratio bandwidth of 20%. We measured axial ratio, radiation patterns and antenna gain of the configuration are presented and discussed     

Bandwidth enhancement of inset-microstrip-line-fedequilateral-triangular microstrip antenna

By embedding a pair of properly-bent narrow slots in an equilateral-triangular microstrip patch, broadband operation of microstrip antennas with an inset microstrip-line feed can be achieved. With the proposed antenna design, the impedance bandwidth can be as large as ~3.0 times that of a corresponding simple triangular microstrip antenna. Some simple design rules for the proposed antenna have also been determined experimentally. The design rules and experimental results are presented and discussed     

Reduction of antenna dimensions by dielectric loading

Measurements are presented to show that Yagi and resonant-slot antennas can be reduced in size if loaded with dielectric material. The effect on bandwidth, radiation resistance and the radiation patterns is discussed, and the loss in the material is recognised as the crucial parameter constraining the usefulness of this loading technique.     

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     

Gain-enhanced miniaturised rectangular dielectric resonator antenna

A double-layered high permittivity dielectric resonator (DR) was investigated experimentally at the 1.8 GHz band. The measured results show that the double-layered DR antenna has a 1.2 dB gain enhancement and 25% height reduction over a single-layered antenna. The bandwidth is 2.7% and antenna gain is 6.2 dBi     

Two-dimensional cylindrical dielectric resonator antenna array

A square 2×2 subarray and infinite phased array of aperture-coupled cylindrical dielectric resonator antennas is investigated experimentally. The return loss, radiation pattern, and antenna gain are studied and compared with those of the single element antenna, and the waveguide simulator is used to measure the return loss of the element in an infinite array environment