Abstract
The polyphase filter approach to quadrature demodulation is shown to be well suited for the implementation of purpose-designed wide bandwidth digital quadrature demodulators. The duplicated polyphase filter approach is introduced, as a way to increase the maximum allowable input signal bandwidth for a given implementation technology. Other algorithmic and architectural considerations specifically applicable to the realization of digital filters in low-cost Field-Programmable Gate Array (FPGA) technology are discussed. A design example suitable for processing input signals centered on an intermediate frequency of 160 MHz with a bandwidth of ∼45 MHz is presented. This design occupies 83% of the Configurable Logic Blocks (CLBs) in a low-cost Xilinx X4010E-3 FPGA. Additional techniques for further performance optimization are presented.
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Langlois, J., Al-Khalili, D. & Inkol, R. Polyphase Filter Approach for High Performance, FPGA-Based Quadrature Demodulation. The Journal of VLSI Signal Processing-Systems for Signal, Image, and Video Technology 32, 237–254 (2002). https://doi.org/10.1023/A:1020268902913
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DOI: https://doi.org/10.1023/A:1020268902913