Reconfigurable FPGA-Based Channelization Using Polyphase Filter Banks for Quantum Computing Systems

Recently proposed quantum systems use frequency multiplexed qubit technology for readout electronics rather than analog circuitry, to increase cost effectiveness of the system. In order to restore individual channels for further processing, these systems require a demultiplexing or channelization approach which can process high data rates with low latency and uses few hardware resources. In this paper, a low latency, adaptable, FPGA-based channelizer using the Polyphase Filter Bank (PFB) signal processing algorithm is presented. As only a single prototype lowpass filter needs to be designed to process all channels, PFBs can be easily adapted to different requirements and further allow for simplified filter design. Due to reutilization of the same filter for each channel they also reduce hardware resource utilization when compared to the traditional Digital Down Conversion approach. The realized system architecture is extensively generic, allowing the user to select from different numbers of channels, sample bit widths and throughput specifications. For a test setup using a 28 coefficient transpose filter and 4 output channels, the proposed architecture yields a throughput of 12.8 Gb/s with a latency of 7 clock cycles.