I am trying to design a simple bandpass filter and I am confused what should be my central frequency and bandwidth should be.
I have a 1MHz square wave with 20% duty cycle, so the signal is on for 200nsec and off for 800nsec. I have a rise time and fall time of 10nsec.
The desired filter is passing this signal and eliminating all the noise. If my bandpass filter centered around 1MHz, how wide it should be so that I can maintain a decent rise time. According to the relationship between rise time and bandwidth (0.34=tr*BW) my signal bandwidth to observe 10nsec rise time is 34MHz. If my filter is 1MHz +/-5KHz, I would loose the rise time granularity (At least this is what I think since the FFT of that sharp edge will be in higher frequencies and will be cut off)
Bonus question: How can I design a BP filter that still allows for sharp rise and fall time and narrow around 1MHz?