I was wondering if it's possible to turn a PC into a signal generator through the ethernet port (or at least an amplitude-modulated sine generator). I specifically care about the ethernet port since it has a high datarate. Yes, I know that it's made for primarily digital communication, but since it's just a transmission line with multiple channels, and thus a piece of metal, it should be possible to send analog data as long asif computer hardware can somehow support it, analog signals should be able to travel over the cable easily, even in the low GHz frequency range before higher modes become a problem.
If the computer hardware can't support it, I figure it could still be possible in theory, to at least send purely digital datasquare waves and use some kind of device/filter that changes "packets" of bits intoon the other side to create a poor man's amplitude-modulated sine wave, thatsignal. This could then be repeated from a different port/computer, and the two signals used as an I/Q signal coming intosignals for a vector signal generator.
Has anyone heard of such an application before? Is it technically possible? I ideally want to create a 1 GHz I/Q signal over good network card, but it might be a ridiculous stretch because I don't know what the practical limitations are. Even tens to hundreds of MHz would be a win.