@aroosababar11 , I don't know of any Arduino that can generate close to a 900MHz signal (or even 500MHz) using software alone. I think you are going to need some additional hardware that can be controlled by your Arduino in order to do that.
Charge Pump CircuitScreenshot (160)|690x387 Arduino ProgrammingIn this programming delay is giving the frequency but the problem is that only delay of milliseconds (frequency=K Hz) gives the best nonoverlapping Pulses of 50% duty cycle. When I decrease the delay to increase the frequency, the pulses are not perfect hence charge pump circuit does not approach to its desired output Screenshot (159)|690x387
Looking at the picture of the code you are running and a picture is a silly way to post code, the the line
delay(0.000000555);
Is just stupid.
The delay function takes a integer of the number of milliseconds of delay.
You have given it a floating point value. Any decent simulator should have choked at that line, just like a real Arduino. The fact it didn't shows what a useless, piss poor, piece of software it is, and your whole project here is just meaningless.
Was I believe a joke. There is no real hardware that runs at this clock frequency.
Yes and no. The project itself is a joke - simulate something that won't work in real life. The hardware required to generate the pulse trains and the amplifiers required to drive the charge pump are problems beyond the capabilities of Proteus digital simulation.