And as the spectrum of a discrete time signal, this exact same spectrum will periodically repeat if we extended the frequency increased over and above $f_s$ such that the spectrum demonstrated is likewise the exact same spectrum in every frequency band from $nf_s$ to $(n+1)f_s$ for virtually any integer $n$. https://pginsector15gurugram.tech.blog/2025/07/28/book-modern-pg-for-boys-in-gurgaon-osmstays/