3 ms·
The reference signal generated by Si5351A is used to clock two flip flops which I believe are used to generate a 90° quadrature local oscillator (LO) which ente
by picture 2y ago
The reference signal generated by Si5351A is used to clock two flip flops which I believe are used to generate a 90° quadrature local oscillator (LO) which enters a dual 1-4 multiplexer acting as a Tayloe quadrature mixer. And as you know, the nonlinear switching action introduces frequency products and allows frequency conversion.
This is a pretty clever system. The RF is low enough frequency that faster logic chips can be used effectively. I recommend getting yourself a cheap receive-only SDR for around 15 bucks and play with GNURadio, if you want to get more familiar with DSP for telecommunications/radio detection
- _benj 2y agoThanks! I think the limitation is in my knowledge and not in the article or schematics! I have a rtl-sdr and I’ve played with gnu radio, but the signals that I had to explore were very limited! Apart from few remotes for fans and stuff around the house I only had fm radio and little more. What I find very interesting from this is the possibility of taking a Si5351A breakout board, configuring it with I2C (I can do that), modulate it with something like audio and a mixer (I can code that… maybe) and plug that directly, likely through and attenuator, to gnu radio! It would certainly be a lot easier to get a sdr transmitter, but I wasn’t aware of the possibility of modulating a Si5351A with a “simple” signal like 48kHz audio!