A 2-22 GHz low-imbalanced active balun in 0.18 μm SiGe BiCMOS technology

A 2-22 GHz broadband active balun using 0.18 μm BiCMOS technology is presented. In this paper, an analysis of the imbalance of the active balun and the optimization method are given. The proposed active balun achieves a low-imbalanced performance. The imbalance of the differential output is less than 0.26 dB in amplitude and less than 0.80° in phase. Using active inductor technique, the active balun results in a compact area of 0.74 × 0.67 mm2, including bandgap circuit and all pads. The core active balun has a power consumption of 42 mW from 3.3 V supply voltage.