What is the shape of EMwaves in space ?

hi

please help me in this this confusion ,if anyone knows........about EMwaves.

As we know, the noise always ADD on our signal, or we can say that if x is our signal and y is any noise ,we can add them by using mixer , their Addition
say d=x+y ; d is signal containing our signal and added noise fron Atmosphere. here '+' we can say it mixer in our real life .

Q: my question is , as there are many signals in the Space ; what is their physical shape ? Is their is any mixer that add all signals in the space.


regards