A Low-Cost Wideband Reflectarray Antenna Based on Nonradiative Dielectric Waveguide

A wideband reflectarray antenna (RA) with improved efficiency is proposed based on nonradiative dielectric waveguide unit cells. The inherent nonresonant nature of the waveguide is utilized to achieve wideband performance. In contrast to conventional rectangular waveguide-based RA, the proposed design simplifies the unit cell structure by eliminating a pair of conductor walls and the metal ground used for reflecting the incident electromagnetic wave. In addition, the proposed design achieves a compact unit cell size of 0.43λ × 0.44λ, where λ represents the free-space wavelength at the center frequency (10 GHz). The single-layer dielectric is employed for the RA design instead of previously reported multilayer or stacked layers to achieve the comparable performance. The prototype consists of 16 × 16 unit cells, with the dielectric components fabricated by 3-D printing technology. The measurements show that the 1 dB and 3 dB gain bandwidths of 18% and 27% are realized, respectively, with a peak aperture efficiency of 45%. Both of the simulations and measurements validate that the proposed design enables wideband and improved efficiency using a low-cost compact structure.