A low loss reflectarray element based on a Dielectric Resonator Antenna (DRA) with a parasitic strip (original) (raw)

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.

Dra Reflectarray Unit Elements With Thin Under-Loading Parallel Slots

Progress In Electromagnetics Research C, 2014

This paper presents three dielectric resonator (DR) unit elements loaded with one, two, and three narrow slots underneath for designing reflectarrays. The slots are aligned in parallel, and the lengths are varied to function as phase shifter for changing reflection phase. It is found that the dominant TE mode of the square DR element can be easily excited by placing multiple parallel slots beneath a DR element. Study shows that the number and width of the slots can be used as additional design parameters for tuning the reflection loss and phase range of the reflectarray. Rectangular waveguide method has been deployed, showing reasonable agreement between simulation and measurement. It is found that a reasonable reflection phase range of 313 • with slow slope is obtainable when the DRA is loaded with two slots beneath, which can be used for designing a small-size reflectarray. The reflection characteristics of the unit elements are studied, along with a complete parametric analysis.

Comparison of Resonant Elements of Microstrip Reflectarray Antenna for Ku-Band Applications

2017

Design of unit cell of Microstrip Reflectarray Antenna (MRA) is one of important parameters. Using infinite array approach method, resonant element of MRA is observed in unit cell environment. The reflection phase curve helps to characterize different shapes of resonant elements. Keywords— Unit-cell environment, Infinite array approach, Reflection Phase Curve, Figure of Merit, Static Phase Range

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%.

Perforated Dielectric Resonator Antenna Reflectarray

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.

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.

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).

Linearly Polarized Fed Circularly Polarized DRA Reflectarray

International journal of electromagnetics and applications, 2012

Two dielectric resonator antennas are discussed to generate circularly polarized waves in a reflectarray antenna. In this case, two models are discussed here, one is DRA supported on cross slot, while the second is aperture coupled DRA supported on cross strip line coupled to DRA by cross slot. The verification of reflection coefficient phase of cell is satisfied by CST microwave studio and HFSS package. A complete array of 15 x 15 fed by a circular horn tilted by 45 degree was designed and simulated at X-band by full wave package. The simulated results show that the obtained 1.5-dB gain bandwidth and 3-dB axial ratio bandwidth of the reflectarray with aperture coupled DRA can reach as large as 25% and 12.5%.