Aldo Petosa

Recent advances in dielectric-resonator antenna technology

This paper features some of the advances in dielectric-resonator antenna technology at the Communications Research Centre. Several novel elements are presented that offer significant enhancements to parameters such as impedance bandwidth, circular-polarization bandwidth, gain, or coupling to various feed structures. Several linear and planar arrays are also presented, to illustrate the performance of dielectric-resonator antenna elements in the array environment.

Dielectric Resonator Antennas: A Historical Review and the Current State of the Art

This article presents a historical review of the research carried out on dielectric resonator antennas (DRAs) over the last three decades. Major research activities in each decade are highlighted. The current state of the art of dielectric-resonator-antenna technology is then reviewed. The achievable performance of dielectric resonator antennas designed for compactness, wide impedance bandwidth, low profiles, circular polarization, or high gain are illustrated. The latest developments in dielectric-resonator-antenna arrays and fabrication techniques are also examined.

Design and analysis of multisegment dielectric resonator antennas

The multisegment dielectric resonator antenna (SDRA) has previously been developed to significantly enhance the coupling to a microstrip line. The MSDRA greatly facilitates the integration with a printed feed distribution network for use in a large array environment. The thickness and permittivity of the dielectric insert of the MSDRA can be adjusted to match the element impedance to that of the feed line. A detailed study of the effects of varying the dielectric insert parameters was carried out and useful guidelines are presented for the design of MSDRAs.

Improved Design Guidelines for the Ultra Wideband Monopole-Dielectric Resonator Antenna

This letter examines in detail multiple resonance phenomenon responsible for the ultra wideband response of the hybrid monopole-dielectric resonator antenna (DRA). The physical insight gained by this investigation has lead to improved guidelines for designing the antennas for any specified frequency band. These simple guidelines are then verified using both simulated and measured data

An investigation of a novel broadband dielectric resonator antenna

Recently, dielectric resonator antennas (DRA) have been proposed as an alternative to the popular microstrip patch. Since then, research has continued, extending their performance capabilities and confirming their potential as low profile and efficient antenna elements for array applications. Also a single-point fed dielectric resonator antenna has been reported, capable of radiating a circularly polarized signal with a much wider axial ratio bandwidth than a similar single-point fed microstrip patch. Further capability enhancements of a dielectric resonator antenna have recently been demonstrated by fabricating the antenna from ferrite material. With a properly biased static magnetic field, it has been shown to possess frequency tuning and polarization diversity properties. The purpose of this paper is to present a novel development of a DRA which possesses a much wider operational bandwidth than previously reported. This improvement can be accomplished with a simple slot feed and without an elaborate matching circuit or a complicated stacking procedure which is generally required by the microstrip patch.

Rectangular Dielectric Resonator Antennas With Enhanced Gain

Rectangular dielectric resonator antennas were designed to operate at high-order modes to achieve enhanced gain. A simple model was developed to predict the radiation patterns of the higher-order modes. Prototypes designed at 11 GHz showed gains of up to 5 dB above those obtained by the fundamental mode.

Research and Development on Phase-Shifting Surfaces (PSSs)

Phase-shifting surfaces (PSSs) developed in recent years are reported. Research and development on these phase-shifting surfaces are set in the historical context of prior-art free-standing lensing devices, as well as in the context of recent studies performed by other research groups. In addition, initial work on a phase- and amplitude-shifting surface (PASS), an extension of the phase-shifting surface, is demonstrated in a beam-shaping application.

A Ka-Band Dielectric Resonator Antenna Reflectarray

A reflectarray that uses a Dielectric Resonator Antenna (DRA) as the radiating element has been developed at Ka-Band. A variable length DRA provides the required phase shift at each cell on the reflectarray surface. Experimental results for this configuration show a similar performance to reflectarrays based on microstrip patch antennas.

Material characterization using a quasi-optical measurement system

Application of a quasi-optical apparatus in the determination of the constituent parameters of materials is presented in this paper. Correction terms are introduced to remove the errors due to the misplacement of the sample and the calibration procedure. Good agreement was observed between manufacturer specifications and measurements after application of the correction terms.

An Overview of Tuning Techniques for Frequency-Agile Antennas

Frequency-agile antennas can be designed to switch between a set of discrete frequencies, or to be tuned over a continuous range of frequencies. Methods for achieving discrete or continuous frequency tuning can be grouped into three categories: mechanical actuation, tunable materials, and integrated electronic devices. Example tuning techniques in each class are presented, highlighting strengths and weaknesses of each method.