A broadband high linearity inductorless CMOS variable gain amplifier for square kilometer array

This paper presents a high-bandwidth 2 GHz CMOS variable gain amplifier (VGA) for using in the band of square kilometer array (SKA) range that achieves an 18 dB dynamic range (DR) while powered from a single 1.8 V supply. This VGA capability is obtained by employing a passive digital T-bridge attenuator followed by a fixed amplifier, the use of attenuator in the front end of the VGA results in a high linearity of 28 dBm to 34 dBm over the full DR. In contrast to traditional VGAs [5], [6], the VGA exhibits 30-50 dB more in DR while its bandwidth and IP3 extends below the presented.