A novel dual-band rat-race coupler

摘要

In this paper, a new dual-band 3dB 180° hybrid ring coupler is presented. The proposed coupler is composed of multiple transmission lines with identical characteristic impedance and electrical length and a dual-band 180° phase shifter. Based on the even-odd analysis, it is found that the proposed coupler can support a wide range of frequency ratio since its realization is mainly limited by the implementation of the dual-band 180° phase shifter. To prove the design concept, full-wave electromagnetic simulations are performed and an experimental prototype is fabricated. The measurement results match well with the theoretical and numerical results.