A high isolation quasi-circulator with self-adjusting technique

In this paper, a new architecture of quasi-circulator for use in a duplex system is presented. A quasi-circulator could be used on a wireless duplex system if we could overcome the problem of TX-to-RX leakage. Through the method of signal cancelling and the technique of the using of reflection tuner, a higher TX-to-RX isolation in this system is achieved. The measurements of this designed quasi-circulator show a high TX-to-RX isolation with the frequency from 1.8 GHz to 2.0 GHz, −66dB isolation is achieved at the center frequency, 1.9 GHz.