The question is, does a RF frequency multiplier work with ultrashort pulses?
In another words, does the frequency multiplier change the pulse width of input signal?
For example, suppose we have a analog signal oscillating at 100MHz and it was amplitude modulated to be a 50ns-width Gaussian-shape single pulse (note, there was only 5 periods of signal).
- Will the output signal of frequency doubler/tripler be a 200MHz/300MHz gaussian pulse? What is the pulse width?
- What if the signal was amplitude modulated to be 50ns-width square shape pulse?
【update】 To be more specific, my signal is a frequency modulated analog f0=100MHz pulse with pulse width of ~10μs, where the frequency modulation \$\delta f=\delta f(t)\$ is a function of time during the pulse width.
For example, \$\delta f\$ is about 1MHz at t<5μs, and \$\delta f\$ jumps right away to be ~10MHz at t=5μs, then at t=8μs, \$\delta f\$ jumps to ~15MHz.
I want to extract the frequency jumping curve \$\delta f(t)\$with high time resolution (say, at least with 100ns resolution), but as you can see, the oscillation duration is very short (a few cycles). A short time Fourier transform analysis can not resolve the frequency jump accurately.
So I wonder, can a frequency multiplication process enhance the frequency difference to \$N\delta f(t)\$, but also the frequency jumping curve shape is not changed? Then the core question is, will a frequency multiplier work with short signals with few cycles?
I have read papers that uses frequency multipliers to generate wideband linear frequency modulation (LFM,\$\delta f=\alpha t\$) pulse signal from a narrow band linear frequency modulated signal . I'm not familiar with electronics, but I guess a frequency multiplier will also work on a nonlinear frequency modulated signal? Am I right?