Dynamic range extension for HF receiver frontend

摘要

This paper presents a new HF frontend architecture with two or more parallel receiver branches. Each branch applies a different gain to the input signal before feeding it to the analog-to-digital converters. One branch is designed for best sensitivity; the others are almost identical but driving the analog-to-digital converter with reduced level. For further processing in the digital domain, the receiver selects the branch with the best sensitivity but not saturating its analog-to-digital converter for each sample. Consequently, the receiver is able to perform an automatic gain control on a sample by sample basis. The paper will discuss the dynamic range improvement with different interfering signals.