Millimeter-Wave Substrate-Based Dielectric Reflectarray

A linearly polarized millimeter-wave substrate-based dielectric reflectarray fabricated out of a single low-cost printed circuit board (PCB) is presented in the frequency range from 30 to 40 GHz. Its unit cell has a cylindrical dielectric resonator (DR) to obtain the required reflection phase. To avoid the alignment problem, the DR has four dielectric arms for connecting itself to its adjacent DR elements. By varying the radius of the DR element, a linear reflection-phase response that fully covers 360° can be obtained at 35 GHz. For demonstration, a circular DR reflectarray is designed and fabricated at 35 GHz and a measured peak antenna gain of 23.9 dBi is obtained.