I am generating a digital signal with software. I have defined the vector $$[0,1,1,1,0,1,0,1,0,1,0,0,0,0,0,0,0,0,0,0] $$ and my sampling rate is 8 million per second.
The frequency spectrum is periodic, with bandwidth of each spectrum being 8 MHz I guess (I do not see 4 MHz as the highest frequency on my GUI, I see a frequency way smaller, which I do not understand).
Then, in order to see the generated signal better, I have repeated each vector value 800 times. This gave me a pulse width of 100 microseconds long (1/8000000*800).
My question is How would repeating each vector affect the frequency spectrum? How come can I see only one peak after repeating each vector (800 times) in my FFT spectrum GUI? Shouldn't it stay periodic since I am still looking at a digital signal?