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.

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

This paper explains the basic characteristics of dielectric resonator antennas (DRAs), with emphasis on the effect of the form factor on their resonance (operating) frequencies. It is followed by discussions on their recent developments in higher order mode, circularly polarized, dual function, and transparent designs over the last few years. The idea of using glass DRAs as decoration antennas is proposed and demonstrated for the first time.

Dielectric Resonator Antennas: From the Basic to the Aesthetic

A new approach is proposed to reject certain bands within the passband of an ultra-wideband planar monopole antenna. The proposed approach that utilizes a mushroom-type electromagnetic-bandgap (EBG) structure is proven to be an effective way for band-notched designs. The approach has many advantages, such as notch-frequency tunability, notch-band width controllable capacity, efficient dual-notch design, and stable radiation patterns. Several design examples using conventional mushroom-type EBG and edge-located vias mushroom-type EBG are presented. The examples exhibit good bandstop characteristics to reject the wireless local-area network interference bands (5.2- and 5.8-GHz bands). Besides, the causes that lead to the discrepancies between the simulations and measurements are discussed.

UWB Band-Notched Monopole Antenna Design Using Electromagnetic-Bandgap Structures

A small-size microstrip-fed multi-band planar monopole antenna is presented. The base of the proposed antenna is a diamond-shaped-patch (DSP) that covers the ultrawideband (UWB) frequency range. To create a multi-band antenna, several narrow strips, acting as resonance paths, can be integrated with the DSP antenna. It is shown that by removing the centre part of the DSP antenna, without distorting the UWB behavior, quarter-wavelength strips can be added to the notched region. This will not affect the dimension of the base antenna. The designed quad-band antenna has a substrate size of 16 × 22 mm2 and covers the frequency bands 1.3, 1.8, 2.4 and 3.1-10.6 GHz which includes GPS, GSM, WLAN and UWB. Dual-, triple- and quad-band antennas are simulated and good results are obtained. The antennas have omnidirectional and stable radiation patterns across all the relevant bands. Moreover, relatively consistent group delays across the UWB frequencies are noticed for the base, dual- and triple-band antennas, and slightly distorted for the quad-band antenna. A prototype of the quad-band antenna is fabricated and measured results are compared with simulated results.

Small UWB Planar Monopole Antenna With Added GPS/GSM/WLAN Bands

In order to prevent interference problem due to existing nearby communication systems within the UWB operating frequency, a compact triple band-notch UWB antenna is presented in this communication. This antenna, designed for the rejection of interference with Worldwide Interoperability for Microwave Access (WiMAX), lower and upper wireless local area networks (WLANs) covering 3.3-3.6 GHz, 5.15-5.35 GHz and 5.725-5.825 GHz, provides three notched bands by only one structure with simple design. Based on simulation and measurement, it shows that the proposed antenna can guarantee a wide bandwidth from 3.03 to 11.4 GHz with triple unwanted band-notches successfully.

Compact UWB Antenna With Multiple Band-Notches for WiMAX and WLAN

To prevent interference problems due to existing nearby communication systems within an ultrawideband (UWB) operating frequency, the significance of an efficient band-notched design is increased. Here, the band-notches are realized by adding independent controllable strips in terms of the notch frequency and the width of the band-notches to the fork shape of the UWB antenna. The size of the flat type band-notched UWB antenna is etched on 24 times 36 mm2 substrate. Two novel antennas are presented. One antenna is designed for single band-notch with a separated strip to cover the 5.15-5.825 GHz band. The second antenna is designed for dual band-notches using two separated strips to cover the 5.15-5.35 GHz band and 5.725-5.825 GHz band. The simulation and measurement show that the proposed antenna achieves a wide bandwidth from 3 to 12 GHz with the dual band-notches successfully.

UWB Antenna With Single or Dual Band-Notches for Lower WLAN Band and Upper WLAN Band

A novel portable dielectric resonator antenna (DRA) design with broadside radiation is presented for ultrawideband wireless applications and narrow pulse sensor for breast cancer detections. The antenna provides broadside radiation. By using a solid rectangular dielectric resonator mounted on a vertical ground plane edge, the total antenna volume is considered to be less than that with a perpendicular ground plane. A wide impedance matching bandwidth is achieved. In addition, a modified version of the rectangular dielectric resonator antenna, which has two dielectric pieces removed to have an A-shaped resonator, provides wider impedance matching bandwidth of around 93% with much better broadside radiation characteristics and lighter weight is also considered. Comparison between the two antennas is presented with parametric study. The modified antenna is built and tested and very good agreement between computed and measured results is obtained.

Ultrawideband Dielectric Resonator Antenna With Broadside Patterns Mounted on a Vertical Ground Plane Edge

A new simple compact monopole type dielectric resonator antenna (DRA) for ultrawideband (UWB, 3.1-10.6 GHz) applications is presented. The design combines the advantages of small size DRA and thin planar monopole antennas. The design provides high-radiation efficiency, consistent omnidirectional characteristics, and low cross polarization within the entire band. The antenna size is 15 × 33 mm2 with 5.08 mm thickness. The dielectric resonator (DR) is shaped to house the excitation feed and the dielectric substrate is cut to house the DR. The coplanar waveguide is used to feed the antenna.

UWB Dielectric Resonator Antenna Having Consistent Omnidirectional Pattern and Low Cross-Polarization Characteristics

A novel UWB DRA structure was designed. By using vertical partial ground plane, impedance bandwidth of 81% was achieved. The antenna is simple and compact in size. Furthermore, it can be used portable to several applications.

UWB dielectric resonator antenna mounted on a vertical ground plane edge

An H-shape ultrawideband (UWB) dielectric resonator (DR) mounted on a vertical ground plane edge with broadside radiation patterns is evaluated for breast tumor detection. In order to scan the whole breast, the proposed DR sensor can be attached to the skin without a need for matching medium. The sensor has a wide half power beamwidth, therefore path loss is reduced. In addition, the DR sensor provides very good pulse-preserving performance such as low distortion and constant gain characteristics with high efficiency. The small footprints of the sensor over the skin allows for more sensors nearby or in contact with the breast skin. Suitability of the compact DR sensor for breast tumor detection can be seen from frequency domain analyses as well as time domain analyses. Accurate tumor response is obtained due to the compact size and very good sensor characteristics.

Kenny Seungwoo Ryu

Papers

UWB Antenna With Single or Dual Band-Notches for Lower WLAN Band and Upper WLAN Band

Ultrawideband Dielectric Resonator Antenna With Broadside Patterns Mounted on a Vertical Ground Plane Edge

UWB Dielectric Resonator Antenna Having Consistent Omnidirectional Pattern and Low Cross-Polarization Characteristics

UWB dielectric resonator antenna mounted on a vertical ground plane edge

Evaluation of Dielectric Resonator Sensor for Near-Field Breast Tumor Detection