Reflect-Array Design for 28 GHz

This paper presents results of a high-gain fixed-beam microstrip reflect-array design for 28 GHz using variable size unit cells. The array employs a simple, single-layer structure on a 0.508 mm Roggers 5880 substrate. It comprises 33×33 unit elements over 198×198 mm surface. Each unit cell is 6x6 mm size, i.e. × 0.56λ
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at 28 GHz, and has a square patch at the center, size of which is varied between 2 mm to 4.5 mm in order to derive a highly directive beam in a desired direction. Simulation results show a highly directive beam, with low side-lobe level for reflection angles in the (-50, 50) range. The array has a gain of 32.5 dBi at 20° beam direction, half-power-beam-width of 3.15°, and a sidelobe level of -17 dB. For the 50° beam direction, the corresponding values are 30 dBi, 5.1° and -15.6 dB, respectively.