A 24-GHz low power and high isolation active quasi-circulator

A 24-GHz novel active quasi-circulator is developed in TSMC 0.18-µm CMOS. We proposed a new architecture by using the canceling mechanism to achieve high isolations and reduce the circuit area. The measured insertion losses |S
32
| and |S
21
| are 9 and 8.5 dB, respectively. The isolation |S
31
| is greater than 30 dB. The dc power consumption is only 9.12 mW with a chip size of 0.35 mm
²
.