Basically, what happens if your signal is switching between frequencies faster than the sample rate of the ADC in the spectrum analyzer? I have been curious as to what would happen in this case, would aliasing from sampling occur?
From what I understand about spectrum analyzers is that they use RF mixer magic and a band pass filter to bring an extremely high frequency signal into a frequency range that can be sampled by a relatively “cheap” and “slow” ADC. From what I understand, I don’t think that magic works to also bring down the switching rate of a signal switching between two frequencies.
A follow up question would be if the amplitude of a 5MHz signal is changing from lets say 10dB to 50dB every 10ns, would an ADC on a spectrum analyzer that samples every 25ns be able to capture the event without aliasing?
From what I understand about sampling is that aliasing would occur and you need a faster ADC (probably a time interleaved ADC) in your spectrum analyzer to capture the event where a signal is switching frequencies or amplitudes faster than the sample rate of the ADC.
If it is possible can you explain how it works?