After seeing the very good result I obtained designing and simulating the AGC using matlab - simulink, I decided to complete the logical path from RF to audio, designing an AM demodulator.

 In this way I could listen to some radio stations at last. I read some articles on the web but the only one I found really interesting is  "An FPGA SDR HF Transceiver by K6JCA" who very well describe the AM demodulator.

A little resume, now I have the following items:

• ADC: done
• sampler: done
• spectrum viewer: done
• Digital down converter, CIC decimator - FIR filter (*)
• AM demodulator (*)
• SSB demodulator: TODO
• AGC (*)
• I2S output: done

(*) designed and simulated but not tested yet

So I'm almost ready to put it all together in my EBAZ4205. 

Talk to you soon!