基于耦合线的高隔离度三频分支线耦合器

Tri-band branch line coupler with high isolation using coupled lines

本文提出了一种应用于无线功率传输系统中的新型三频分支线耦合器.通过在传统分支线耦合器的基础上加载1/4波长短路耦合线来实现3个频段的通带.每个通带之间均保持高的隔离度,且通过改变加载耦合线的奇偶模阻抗值,耦合器通带的中心频率可以在较宽频带范围内调节.对一个工作在0.69/1.0/1.4 GHz的平面三频耦合器模型进行了设计与加工,测试结果与理论期望值吻合较好.

A novel tri-band branch line coupler is proposed for wireless power transmission system.A conventional coupler loaded with quarter-wavelength short coupled lines is adopted to realize the triple passbands.Each passband has a high degree of isolation.The passband center frequencies of the coupler can be adjusted over a wide band by changing the even/odd-mode characteristic impedances of the coupled lines. A planar tri-band coupler located at 0. 69/1. 0/1. 4 GHz is designed and fabricated for verification. Good agreement can be observed between measured results and theoretical expectations.