Aperture coupled microstrip patch antenna with thick ground planein millimetre waves

The finite thickness of the ground plane is taken into account in the cavity model to analyse some aperture coupled microstrip patch antennas at millimetre-wave frequencies (60 GHz). The thickness has a strong effect on impedance matching at high frequencies owing to the ratio between the thickness and the wavelength, which increases with frequency. The calculated results are compared to those obtained by experiment for several antennas with different input impedances due to different slot lengths. Close agreement is found between the calculated and experimental results     

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     

Input impedance of aperture coupled hemispherical dielectric resonator antenna

A hemispherical dielectric resonator (DR) antenna fed by a microstripline through an aperture on the ground plane is investigated both theoretically and experimentally. The broadside TE/sub 111/ mode input impedance of the antenna configuration is evaluated, and reasonable agreement between theory and experiment is obtained. The effects of the slot length and the slot width on the input impedance are studied and discussed.<>     

Aperture coupled microstrip patch antenna fed by nonradiating dielectric waveguide

Owing to its low loss property at millimetre-wave frequencies, the nonradiating dielectric (NRD) waveguide is very attractive for use as a feed network in planar arrays. The design, fabrication and testing of a microstrip patch antenna fed by NRD guide at X-band is described. Radiation patterns are measured and presented.<>     

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.     

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     

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.     

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     

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     

A new inverted F antenna with a ring dielectric resonator

A new antenna combining the use of a ring dielectric resonator (DR) and an inverted F antenna (IFA) is proposed and investigated experimentally. In this application, the DR not only fills the role of a dielectric coating, but also serves the function of a radiator. The measurements of input impedance, return loss, and radiation pattern for both the IFA with the DR (IFA-DR) and the wire IFA (WIFA) are conducted at the S band. The measured data demonstrate that the IFA-DR operates in multiple resonance modes unlike a WIFA. Compared with the WIFA, the one proposed here incorporating a ring DR and an IFA is more attractive in having a smaller size and a larger impedance bandwidth     

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     

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