Comment by baobrien
5 months ago
What does the RF front end look like? I see the Lattice ECP5, but what are you using to go from bits to waves?
5 months ago
What does the RF front end look like? I see the Lattice ECP5, but what are you using to go from bits to waves?
There are ten 640 MSPS ADCs (I+Q per channel and a cal path, per 4-antenna PCB tile). These are custom MASH ΣΔ designs built from discrete diff pair transistors (cost about $0.08 each) and do noise shaping/decimation to get a clean 50 MHz of baseband bandwidth. The 8x DACs are also ΣΔ, using the LVDS pins of the FPGA and some modulating DSP. Mixers are MAX2850/1, LNA are custom design based on Infineon transistor, and RFPA is a Skyworks part meant for WiFi (have iterated on a few model numbers).