A more extreme version of the ADC/DAC projects mentioned here is my (old) project that built a Bluetooth transceiver using just an FPGA and an antenna (and a lo

A more extreme version of the ADC/DAC projects mentioned here is my (old) project that built a Bluetooth transceiver using just an FPGA and an antenna (and a low pass filter if you don't want the FCC coming after you): https://github.com/newhouseb/onebitbt https://github.com/newhouseb/onebitbt Tl;dr: if you blast in/out the right 5GHz binary digital signal from a SERDES block on an FPGA connected to a short wire you can talk to your phone!