A steerable 28 GHz array antenna using branch line coupler

This paper provides details on the design of a beam steerable array antenna for mobile applications at 28 GHz frequency band. The array is designed using a Rogers RT/duroid 5880 substrate material of 0.254 mm thickness and dielectric constant of 2.2. The designed antenna is fed by a 2 × 2 Butler matrix (BM) which also serve as a beam former to obtain the beam scanning of from -16 to 16 degrees. The 6-element array realized a peak gain of 14 dBi at the designed frequency and a wideband that cover 63 % of the frequency range. The designed antenna is applicable to 28 GHz frequency band proposed for future generation mobile communications.