A 130 nm CMOS wideband (0.2 to 3.3 GHz) lownoise variable-gain amplifier (LNVGA) with two active baluns working for phase cancellation is presented herein. The LNVGA aims for a wide gain tuning range which avoids signal compression, while enabling a low noise figure. This figure is kept low by the first stage of the LNVGA, whereas the second stage provides the gain variation. The second stage is able to deliver a wide gain tuning range thanks to the utilization of the phase cancellation technique, which is implemented by two active baluns. Since the phase cancellation technique strongly relies on the balun output balancing, a low-imbalance active balun topology is being herein proposed, analyzed in detail, designed, and tested. This new LNVGA design achieves a gain tuning range of 45 dB, a noise figure of 3.4 dB, and dissipates 19 mW in the maximum gain condition. The circuit was fabricated in 130 nm CMOS with a 1.2 V supply.
