Bulk Isolation Technique for LNA Using 45 nm CMOS Technology

Low noise amplifier (LNA) plays major role in RF front of receivers in transmission systems. It can be designed to operate in various frequency ranges based on application. LNA designed using CMOS technology has bulk and substrate terminals and if resistor is incorporated between these 2 nodes, it forms bulk isolation technique. In this paper, we have designed LNA in 45 nm cadence CMOS technology without feedback where noise figure, gain of the LNA are improved by using the resistor in bulk isolation purpose. Transient response, S parameter analysis and gain improvement are observed for various resistor values in the bulk isolation rule.