Low-noise amplifier comparison at 2 GHz in 0.25-μm and 0.18-μm RF-CMOS and SiGe BiCMOS

Abstract

Low-noise amplifiers (LNAs) have been designed and implemented in 0.25-μm and 0.18-μm SiGe BiCMOS and RF-CMOS technologies. The LNAs have been designed for the same WCDMA application and system specifications, allowing meaningful comparisons to be made. This paper presents the design methodology for these bipolar and CMOS switched-gain LNAs and compares the simulated and measured results. A bypass switch topology is also presented. The results show that each technology can meet WCDMA LNA specifications. Measurements show noise figures of 1.4, 1.7, and 1.1 dB for LNAs implemented in 0.25-μm SiGe BiCMOS, 0.25-μm CMOS, and 0.18-μm SiGe BiCMOS, respectively. These LNAs show 14 to 16 dB of gain and +3 to +4-dBm out-of-band IIP3s at 5 to 6 mA current from 3 V. Of these three measured LNAs, the 0.18-μm bipolar shows the best performance; however, simulations of a 0.18-μm RF-CMOS LNA show further improved IIP3.