Perforated Dielectric Resonator Antenna Reflectarray (original) (raw)

Wideband perforated rectangular dielectric resonator antenna reflectarray

2011 IEEE International Symposium on Antennas and Propagation (APSURSI), 2011

A wideband perforated rectangular dielectric resonator antenna (RDRA) reflectarray is presented. The array of RDRA are formed from one piece of material. Air-filled holes are drilled into the material around the RDRA. This technique of fabricating RDRA reflectarray using perforations eliminates the need to position and bond individual elements in the reflectarray and makes the fabrication of the RDRA reflectarray feasible. The ground plane below the reflectarray elements is folded to form a central rectangular concave dip so that an air-gap is formed between the RDRA elements and the ground plane in order to increase the bandwidth. Full-wave analysis using the finite integration technique is applied. Three cases are studied. In the first one, the horn antenna is placed at the focal point to illuminate the reflectarray and the main beam is in the broadside direction. In the second one, the horn antenna is placed at the focal point and the main beam is at ±30 degrees off broadside direction. In the third one, an offset feed RDRA reflectarray is considered. A variable length RDRA provides the required phase shift at each cell on the reflectarray surface. The normalized gain patterns, the frequency bandwidth, and the aperture efficiency for the above cases are calculated.

Slot-loading rectangular dielectric resonator elements reflectarray

IEEE Middle East Conference on Antennas and Propagation (MECAP 2010), 2010

Reflectarray composed of 23 x 23 elements covering an area of 276 x 276 cm 2 is constructed. The unit cell consists of rectangular DRA, a slot in the ground plane, a dielectric layer, and a conducting ground plane. The full phase of 360 degree of the array elements can be obtained by using two slot-ground plane sizes. The reflectarray is centred fed by linearly polarized pyramidal horn antenna. Full-wave analysis using the finite integration technique is applied. The mutual coupling between the feeding horn and the elements of the reflectarray are considered. At 10 GHz, the antenna provides a 3-dB beamwidth of 6 degree with a gain of 28 dB. The antenna bandwidth within 1dB gain variation is found to be 13% and aperture efficiency of 59%.

Dielectric Resonator Antenna Reflectarrays Mounted on or Embedded in Conformal Surfaces

Progress In Electromagnetics Research C, 2013

In this paper, reflectarrays mounted on or embedded in cylindrical and spherical surfaces are designed, analyzed, and simulated at 11.5 GHz for satellite applications. A unit cell consists of a square dielectric resonator antenna (DRA) mounted on or embedded in metallic conformal ground plane is investigated. The radiation characteristics of the designed reflectarrays are investigated and compared with that of planar reflectarray. A 13×13 planar reflectarray antenna on the x-y plane was designed. By varying the length of the DRA element between 2 mm and 6.2 mm a full range from 0 • to 360 • phase shift can be obtained. The size of each element is equivalent to a compensation phase shift. A maximum directivity of 24.3 dB was achieved while the side lobes were below −12.94 dB in E-plane and −15.79 dB in the H-plane for planar reflectarray. A Full-wave analysis using the finite integration technique (FIT) is applied. The results are validated by comparing with that calculated by transmission line method (TLM).

Bandwidth Enhancement of Dielectric Resonator Reflectarray Antenna

Electromagnetics, 2014

In this work is reported an experimental and theoretical investigation on bandwidth enhancement of dielectric resonator antennas (DRA) using multiple DRAs, arranged according to the stacked configuration. Dielectric resonators antennas (DRAs) have been the subject of many investigations since they were introduced in 1982 by Long. Quite useful for high frequency applications, a dielectric resonator placed over a ground plane can serve as an effective radiator. Recent studies have demonstrated their potential for millimeter wave applications due to their several advantages over microstrip patch antennas such as high radiation efficiency, absence of surface waves and lower ohmic losses particularly at high frequencies. The antenna configuration consists of two cylindrical discs of different ceramic materials stacked vertically, one atop the other, placed above a ground plane, and excited by a coaxial probe. The lateral of the lower cylindrical DRA is placed against a coaxial probe, which excites the HEM11δ mode. The numerical procedure is performed through a soft package based on the finite element method. Excellent agreement between theoretical and experimental is obtained. It is verified the concept of increasing the bandwidth of the dielectric resonator antenna by stacking two DRAs.

Broadband Folded Reflectarray Fed by a Dielectric Resonator Antenna

IEEE Antennas and Wireless Propagation Letters, 2020

In this paper, a broadband folded reflectarray (FRA) is designed and fabricated. The FRA consists of a main reflectarray, the polarizing grid, and a feeding dielectric resonator antenna embedded in its structure. With the help of the multilayered reflecting element, the main reflectarray is capable to provide 90°of polarization rotation and proper phase compensation for linearly polarized incident wave. By altering the microstrip line length, a wide phase coverage can be obtained with good phase linearity. To validate the FRA design, both simulations and experiments are conducted, and good agreements are obtained. The FRA accomplishes 31 % matching bandwidth from 9 to 12.1 GHz. In addition, a high aperture efficiency of 50.3% and the peak gain of 28.08 dBi at 10.8 GHz is achieved. Compared with the published works, the proposed FRA is especially advantageous for low profile and good efficiency.

Design, fabrication and characterization of a dielectric resonator antenna reflectarray in Ka-band

Progress In …, 2010

A new reflectarray configuration is proposed for low-loss applications at millimeter waves. It is based on the use of dielectric resonator antennas (DRA) as radiating unit-cells. The phase response of the elementary cell is controlled by adjusting the length of a parasitic narrow metal strip printed on the top of each DRA. A 330 • phase dynamic range is obtained for DRAs made in rigid thermosetting plastic (ε r = 10). As the antenna radiating aperture is non flat, an original low-cost fabrication process is also introduced in order to fabricate the parasitic strips on the DRA surface. A 24 × 24element array radiating at broadside has been designed at 30 GHz and characterized between 29 and 31 GHz. The antenna gain reaches 28.3 dBi at 31 GHz, and the measured −1 dB-gain radiation bandwidth is 5.2%. The 3.2 dB loss observed between the measured gain and theoretical directivity is mainly due to the spillover loss (2.3 dB). The total dielectric and conductor loss is less than 0.9 dB.

Broadband Reflectarray Antenna on a Periodically Perforated Substrate

IEEE Transactions on Antennas and Propagation, 2016

We propose a broadband single layer reflectarray antenna constituted of a double-screen metallic grating on a periodically perforated low-cost substrate. The reflection characteristics of this structure are computed with a full-wave computational technique which utilizes the dyadic Green's function evaluated by an equivalent transmission line (TL) modeling in the spectral domain. The obtained dyadic Green's function is then used in an integral equation for the induced surface current densities on the metallic gratings. The resulting integral equation is solved by the Galerkin's Method of Moments (MoM) with sub-domain basis functions. With the help of this semi-analytical method, the phase diagram of the reflectarray unit cell is computed. Using the calculated phase diagram, a center-fed reflectarray is designed at a center frequency of 10.5GHz. To validate the numerical results, the designed reflectarray for the X-band (8.95~12.1GHz) is fabricated and measured. The measurements on a 270mm×270mm and F/D =0.95 reflectarray show a maximum gain of 26.57dBi with a 1-dB gain bandwidth of 29.5% and an efficiency of 41% at 10.5 GHz. It is shown that the fabricated reflectarray exhibits reduced Radar Cross-Section (RCS) outside its operating bandwidth.

Transmitarray Using Perforated Dielectric Material for Wideband Applications

Progress In Electromagnetics Research M, 2012

In this paper, linearly polarized transmitarray is investigated as to avoid the usage of multi-layers for improving the bandwidth of transmitarray. The transmitarray is formed from a single dielectric sheet by perforating selected areas of the material. A perforated dielectric layer is divided into square cell elements. Each cell has four holes with the same diameters. Holes with different diameters in the cell elements are used to allow continuous tuning of the transmitted signal's phase over 360 • range with a maximum loss of 3.6 dB at 10 GHz. The transmission coefficient versus the diameter of the holes is calculated by using the finite integration technique. The results are compared with those calculated with transmission line method for verification. The focal-to-diameter ratio of the transmitarray is optimized for lower side lobe level and highest transmitarray gain. A comparison between the transmitarray and the reflectarray with the same aperture area is illustrated.