一种新型宽带环形电桥耦合器设计

A Novel Broadband Hybrid-Ring Directional Coupler

传统四端口环形电桥耦合器的带宽只有10%到20%。为了获得更大的带宽,本文提出了一种改进型环形电桥耦合器。通过额外增加一个隔离臂,新设计可以工作在整个W波段。在此基础上,本文在输入臂上加入了一个切角来改善输出信号的隔离度。仿真研究结果表明,在75GHz到110GHz,两输出信号的幅度不平衡度小于0.07d B,相位不平衡度小于0.37度。相比于未作切角处理的五端口环形电桥,新设计输出端口的隔离度在全频段内大于15.07d B。改进型耦合器可以应用于W波段平衡调制器以及其他需要高输出隔离度的W波段功率分配系统。

The bandwidth of conventional 4 ports hybrid-ring coupler is restricted to 10% to 20%. In order to extend the usable band, a modified hybrid-ring coupler is proposed. By adding an extra isolated arm, the functional bandwidth covers the whole W-band. Besides, a chamfer in the input arm is introduced to increase the output isolation. 3D EM simulation results show that, from 75 GHz to 110 GHz, less than 0.07 d B amplitude difference and less than 0.37 degree phase difference is achieved. Compared with no chamfer 5 ports hybrid-ring, the isolation between the two output ports of the modified structure is more than 15.07 d B. The new design could be applied in W-band balanced modulator and other power dividing situation.