3D-Printed Turnstile Junction Orthomode Transducers: Design, Fabrication, and Measurements

Orthomode transducers (OMTs) are critical for communications, enabling frequency reuse through orthogonal polarization separation, yet traditional manufacturing faces challenges in cost, weight, and complexity at high frequencies. This study explores additive manufacturing (AM) for fabricating high-performance OMTs for X-band and Ka-band applications. Two turnstile-junction-based OMTs were designed, optimizing a symmetrical architecture for low return loss, high isolation, and broadband operation. Both OMTs were fabricated using 3D printing technologies, with a comparative analysis of different AM techniques on performance. Measurements validated simulation results, achieving good return loss for both OMTs and isolation above 35 dB for the X-band and above 25 dB for the Ka-band. These designs meet the requirements of modern communication antenna feed systems across multiple frequency bands. Additionally, 3D printing demonstrates the promising potential of AM in RF component manufacturing, offering performance comparable to traditional metal-machined parts.