Research and Design of Receiver RF Front-end Circuit for Software Radio
Shuang Tao · Modern Electronics Technique · 2010
A RF front-end circuit for software radio was designed,which can operate on short wave and ultra-short wave frequency band(3～89MHz) .The received signal from antenna turns the input signal to 2Vand then transforms to the next class-analog-to-digital converter circuit through front-end filtering,AGC and amplification processing.AGC is the core of the circuit,which takes a form of cascade VGAS and improves the dynamic range and linear range.Taking hardware practical test,the maximum sensitive is-90dBm,the largest dynamic range is 70dB,the system has good linearity and low noise figure.