X-band, high performance, SiGe-heterojunction bipolar transistors-low noise amplifier for phased array radar applications

This study presents an X-band low noise amplifier (LNA) implemented in 0.25 μm SiGe BiCMOS process aiming for phased array radar applications. The LNA is composed of two cascode stages using SiGe heterojunction bipolar transistors to achieve low noise figure, high gain and a better matching to 50 Ω at the input and output, simultaneously. The first stage is designed for low noise performance whereas the second stage is optimised to improve the input third-order intercept point (IIP3). The LNA resulted in a measured gain of 21 dB, a noise figure of 1.52 dB and an IIP3 of -8 dBm at 10 GHz. The active chip area without pads is 620 × 820 μm² and the power dissipation is 22 mW from a 2.2 V power supply. These performance parameters collectively constitute the best figure-of-merit value of 101, reported in similar technologies.