Methodology of Noise Flatness Based on Network Quality Factor in RF Wideband Applications

A noise optimization method for millimeter-wave RF wideband applications is reported. Intrinsic noise laws in wideband RF systems are discovered, and a noise flatness methodology based on a network quality factor algorithm is proposed. This algorithm aims to reduce the total noise in an RF system and increase the noise flatness over a full operating band. An RF wideband front end is investigated to verify the noise optimization theory and maintain circuit performance. Using noise flatness methodology and a SiGe heterojunction bipolar transistor process featuring a f T / f max of 240/280 GHz, the front-end results show good performance and compliance with the proposed method.