I would like to design and build a tunable lowpass filter. I would like to adjust the cutoff frequency from 1 MHz to 500 MHz. Requirement on the resolution would be something like 10-50 MHz, obviously, it's not that critical.
I am going to send a programmable clock signal through this filter and want to reduce the high frequency harmonics. I am only using the clock signal as a simple way to get a programmable sinusoidal signal, hence the need for the filter. I was considering using the ADF4110, ADF4350, or one of the Silicon Labs Si570/571 as the programmable clock. I was told that a tunable lowpass filter over this range may be tricky, so I thought it best to consult the StackExchange. I am open to any suggestions.
Ultimately, what I'm trying to accomplish is get a sinusoidal signal that will sweep from 1-500 MHz.