Field Programmable Gate Array
Understanding FPGAs in RF
FPGAs have become indispensable in modern RF systems. Their ability to process wide-bandwidth digital signals in real-time, combined with the flexibility to reprogram for different waveforms and standards, makes them the processor of choice for software-defined radio, digital beamforming, and DPD systems.
FPGA Applications in RF
- DDS: Direct frequency synthesis from digital samples at GHz rates.
- Digital beamforming: Real-time weight computation and application for phased array processing.
- DPD: Real-time predistortion of PA input to linearize output.
- Channelization: Polyphase filterbank to separate dozens of channels from a wideband digitized spectrum.
- Demodulation: Real-time symbol recovery and decoding.
Major FPGA Families for RF
- AMD/Xilinx Versal: AI cores + FPGA logic. Up to 2M logic cells.
- Intel/Altera Agilex: PCIe Gen 5, 116 Gbps transceivers.
- AMD/Xilinx RFSoC: Integrated RF ADC/DAC + FPGA. The standard for SDR.
Frequently Asked Questions
What is an FPGA?
An FPGA is a programmable digital IC that implements any digital function in hardware. In RF systems, FPGAs perform DDS, beamforming, DPD, channelization, and demodulation at multi-GHz sample rates. They combine software flexibility with hardware speed.
What is RFSoC?
RFSoC (RF System-on-Chip) integrates multi-GHz ADCs, DACs, and FPGA fabric on a single chip. It replaces separate ADC/DAC boards plus FPGA boards, dramatically reducing size, cost, and power for software-defined radio and digital beamforming.
FPGA vs ASIC for RF processing?
FPGA: reprogrammable, flexible, faster time to market, lower NRE cost. ASIC: fixed function, higher performance, lower per-unit cost at volume, lower power. FPGAs are used for prototyping and moderate-volume production; ASICs for high-volume consumer products.