Wide Gain Bandwidth Beam-Steering Transmitarray Utilizing Additive Manufacturing and Metal Machining for Satellite Communication

This paper presents a beam-steering transmitarray antenna that leverages a hybrid fabrication approach to enhance bandwidth performance across the 24–30.5 GHz range. The core transmitarray element combines a metal-machined waveguide with an additively manufactured cross-shaped dielectric insert (${ϵ}_r$ = 2.2), achieving both structural precision and design flexibility. Each element measures approximately $0.9\lambda \times 0.9\lambda \times 1.8\lambda$ at 28 GHz. A wideband horn antenna mounted on a 3D-printed stand serves as the feed, with beam steering achieved through mechanical movement along the x and y axes, covering $\pm 12^{\circ }$ in both principal planes. The antenna attains a peak broadside gain of 22.4 dBi with only 1.3 dB steering loss, while its robust construction supports its use in harsh environments, making it well-suited for satellite communication applications.