Reconfigurable Gyration and Isolation through Nonreciprocal Coupling to Resonators with Tunable Q-Factor

This paper presents experimental measurements of a 1.4 GHz gyrator and isolator based on modulation-induced nonreciprocal coupling, implemented in a microstrip circuit. A tunable microwave amplifier is used to tune the Q-factor of the resonant circuit, which can be reconfigured between lossless gyration and lossy isolation. Bandwidth tuning is also demonstrated for both gyration and isolation.