【应用手册】Polyphase Modulation Using a FPGA for High-Speed Applications
This application note reviews and analyzes a polyphase modulation
scheme that generates high-frequency intermediate frequency (IF) carrier
signals in digital IF modems using an Altera® FPGA. Modulating IF
signals to higher carrier frequencies takes full advantage of the high
sampling rate of modern digital-to-analog converters and eases the
requirement for analog voltage-controlled oscillators (VCO) and mixers.
This application note presents a mathematical model of the polyphase
system which provides insights into system parameter selections. In
particular, this application note discusses the polyphase filter design.an511.pdf