一种新型宽带环形电桥耦合器设计

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0.07dB,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15.07dB。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。

A Novel Broadband Hybrid-Ring Directional Coupler

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 dB 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 dB. The new design could be applied in W-band balanced modulator and other power dividing situation.