This is the "Elephant in room" for me, designing and building the analog part of the front end. I know the theory I can apply some intuition on top but in the end is open to experimentation. Because I took the "brilliant" decision not to have a mixer in the front end and directly sample (actually under sample) the RF now I have to deal with larger frequencies (the opposite of simple) and I saved the cents to spend the dollars. The VGA (variable gain amplifier) in front of the ADC now it needs...

Next step in building the radio is to prepare to interface with the ADC (LTC2314-14) which is sending the samples in serial stream very much like SPI but has timing requirements in order to trigger the conversion and give sufficient time to complete the conversion. The datasheet is showing three timing diagrams two are pushing the timing to the limits and the third is more relaxed and easier to implement. The whole conversion cycle is taking 20 clk cycles, 16 cycles to transfer the result of...

In order to make experiments we need to be able to hear the audio and I found a PMOD module in one of my boxes which fits perfectly my FPGA board. The module is question is pictured below PMOD AMP3 link to the manual https://digilent.com/reference/pmod/pmodamp3/reference-manual This module is using a I2S digital interface and master clock (MCLK) from the FPGA and can be used with i2C control or standalone (jumpers) I'm using without I2C for the time being in default settings. (256 Fs MCLK,...