▎ 摘　　要

A Faraday isolator based on magnetically biased graphene is proposed and analyzed. The isolator consists of two rectangular waveguides, two circular-rectangular transitions and a circular cylindrical waveguide loaded multiple graphene sheets, with a static magnetic field which parallel to the signal transmission direction biased. The principles of the isolator have been investigated using the mode-matching technique. The isolation is calculated by the signal flow diagram combined with the transmission matrix method. The theoretical results show that its isolation is more than 30 dB in the working frequency (1.8 GHz-2.2 GHz). The isolation can be tuned by varying the chemical potential or varying the magnetic field. The novel isolator has a simple structure and a wider bandwidth compared to the conventional Faraday isolator. Simultaneously the transmission direction of the isolator can be changed easily by changing the direction of the magnetic field. (C) 2017 Elsevier GmbH. All rights reserved.