where low pass filters are used ?

Hi,
could some1 list me few applications where stepped impedance low pass filters are used frequency range from 0-2.5Ghz?
is it used in communication devices ?

You can easily create this list yourself. Just use www.google.com and search for

stepped impedance low pass filter

harmonic filter in transmitter

Mixer Circuits will often have a LPF in the IF output to reject any LO & RF leakage.