Recently I did a similar project in which a malicious hardware device leaks a victim's data (Password, credit card #, etc.) through a similar technique. We use

Recently I did a similar project in which a malicious hardware device leaks a victim's data (Password, credit card #, etc.) through a similar technique. We used an FPGA though, so with a 100 Mhz fundamental frequency we had harmonics well into the 1.5 Ghz. We called it CPU-SDR. Video here: https://sites.google.com/a/groundworkstech.com/index/blog/rsa-2014---about-cpu-backdoors-and-data-exfiltration https://sites.google.com/a/groundworkstech.com/index/blog/rs... Bonus: Using mutiple PCB traces, you have a basic Yagi-like directional antenna. Feeding different traces you can modify the RF radiation pattern it in real-time.