Microwave (1.5 - 5GHz) LPF application

Does anybody know if there exists an application for such LPF?
I know how to do that filter with a very wide rejection band and distributed elements, with a small size.
I′m looking for standar information (wi-fi,BT,WiGig,...) but there is no physical specifications for channel filters , where could I find it?

TY!

thats not that broad band. Broadband rejection would be 1.5 to 18 ghz. Still, in a WLan, that would reject the 2nd harmonic of 2.45 GHz.

Sorry, with 1.5-5GHz, I meant the cutoff frequency. And, yes, It would be, at least to 15GHz of rejection.
I′d like to find some standard specification to apply this design.