Having fixed the spelling error from the "NIntegrate and Unit Step" thread, I'm now getting an answer of zero when applying NIntegrate to one period of a 50% duty cycle unit pulse of 61.0352 nsec duration. I should be getting an answer of 0.5. A notebook showing the calculation is attached. I used both UnitStep and HeavisideTheta to form the pulse. The answer was the same. So it looks like some sort of precision issue to me but I'm not sure. Anyone have any ideas on how I can get NIntegrate to give me the correct 0.5 for this case? What motivated this is that I'm getting the same zero result for DC term result when applying FourierSeries to this pulse.
I get an answer of 0.5 using the code I attached to your earlier post. Are you sure you are setting the limits of integration correctly? In your first posting they are not set right.