The design of an additively manufactured circular waveguide 3-dB hybrid directional coupler is proposed and demonstrated. Asymmetric corner radius perturbations at the in-plane orthogonal junction of the four waveguides along with curvilinear inductive posts designed to interact with the TE11 mode of the circular waveguide are used to facilitate directivity and isolation. Capacitive waveguide perturbations at each of the four ports provide impedance matching. The proposed design is engineered to operate within V-band from 57 to 64 GHz and provide both 10-dB isolation and return loss and a 90° phase difference between the direct and coupled ports. A commercially available stereolithography (SLA) printer is used to fabricate the hybrid coupler as well as the rectangular-to-circular tapered mode transducers and the thru, reflect, line (TRL) calibration components required for experiments. The printed couplers are metallized using an electroless silver plating process by a closed-loop bidirectional multiport pump-driven fluidic system. Results from the experiment and the simulation are provided.

中文翻译：

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圆形波导中的 3D 打印定向耦合器


提出并论证了增材制造圆形波导 3 dB 混合定向耦合器的设计。四个波导的面内正交连接处的不对称角半径扰动以及设计用于与圆形波导的 TE11 模式相互作用的曲线感应柱用于促进方向性和隔离。四个端口中每个端口处的电容波导扰动提供阻抗匹配。所提出的设计设计为在 57 至 64 GHz 的 V 频段内运行，并提供 10 dB 隔离和回波损耗以及直接端口和耦合端口之间的 90° 相位差。使用商用立体光刻 (SLA) 打印机来制造混合耦合器以及实验所需的矩形到圆形锥形模式传感器和直通反射线 (TRL) 校准组件。印刷耦合器通过闭环双向多端口泵驱动流体系统采用化学镀银工艺进行金属化。提供了实验和模拟的结果。