Building a Wideband SDR Frontend: Signal Chain from ADC to FPGA
The core of Software Defined Radio (SDR): digitize the RF signal as early as possible, and leave the signal processing to the FPGA. A typical wideband SDR frontend chain is: antenna → LNA → mixer → ADC → FPGA (DDC + FFT + demodulation). Along this chain, FPGA transceiver bandwidth, DDR buffering, and DSP horsepower determine how wide an instantaneous bandwidth you can achieve.