Additive Manufacturing of a High-Performance $Q$ -Band Circular TE01 Mode Flared-Type Transducer

This letter presents a Q-band mode transducer based on a slowly flared structure to convert the rectangular TE10 mode into the circular TE01 mode, with an excellent performance in return loss level and conversion purity, overcoming the main issues of this kind of structures: its manufacturing complexity and high cost. They have been tackled by means of the additive manufacturing technology using selective laser sintering, especially well-suited for this problem allowing a single part suitable for high-power applications. The prototype shows a minimum return loss level of 20 dB in the whole Q-band. Measurements have been carried out using four different angles to connect two equal transducers in a back-to-back configuration (0°, 45°, 90°, and 180°). Furthermore, in spite of the expected roughness of the laser sintering, a measured converting efficiency higher than 82% in a 41% relative frequency bandwidth has been achieved. Therefore, the experimental results validate both the proposed geometry and the technology used for its implementation.