A Novel Circuit Topology of Forward-Wave Directional Coupler

作者：Xin Yi, Yongrong Shi, Xingcheng Qian, Zhengyong Yu · 年份：2019 · DOI：10.1109/iwem.2019.8887918 · 研究领域：Microwave Engineering and Waveguides、Radio Frequency Integrated Circuit Design、Photonic and Optical Devices

To achieve a miniaturized forward-wave directional coupler (FWDC) chip based on the integrated passive device (IPD) process, a novel circuit topology is proposed in this paper. The circuit characteristics of the unit cell for even/odd modes are derived using Bloch-Floquet theory. The coupler can be designed with ultra-compact size and increased the phase differences of the even/odd modes. The coupling level can reach 1.5 dB from 9.2 GHz to 13.2 GHz. The fractional bandwidth is 12% and the coupling length is about 0.1 \pmbλg. Due to the IPD process, the coupler in this work can be realized within ultra-compact size.