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

Abstract

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 (εr = 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.