I am reading this article:
https://lpsa.swarthmore.edu/Fourier/Series/ExFS.html#EvenPulse
The following plot is depicted there.
This is called a rectangular pulse function.
The article states then
$$x_T(t) = \left\{ {\matrix{ {A,\quad |t| \le {{{T_p}} \over 2}} \cr {0,\quad |t| \gt {{{T_p}} \over 2}} \cr } } \right.,\quad \quad - {T \over 2} < t \le {T \over 2}$$
However, I want this function to extend over the entire domain of $\mathbb{R}$, just as $\sin(t)$ and $\cos(t)$ do.
How can I extend this function so it covers the entire domain of $\mathbb{R}$?

