In this paper two Low-Noise Amplifiers (LNA) are presented. The first topology is a two-stage LNA that is ac coupled to the mixer, while the second one is a single stage LNA that can be dc coupled to the mixer. These circuits have small sensitivity to temperature variations and special biasing techniques allow us to reduce the effects of the process tolerances. Preliminary experimental results obtained from a prototype, not properly packaged for high frequency applications, have shown that the proposed technique works properly up to 250 MHz. These circuits have been fabricated in an 8-GHz 1.2 m BiCMOS technology.
