Ok lets suppose there is a backdoor system embedded on a processor or CPU IC. This system (core, embedded os) can be activated only by RF. I don't know the frequency (range) which it uses. So my question is would there be any way to activate this backdoor system via RF ? Suppose the pass band features of the band-pass filter can be measured with the use of network analyzer to measure its S12 or S21 parameters. This gives an idea of the frequency range this system uses.