dual frequency transformer for dualband filter..

hi friends please help me to design dualfrequency transformer for dualband filter.. can we do this filter without transformer? if it is so guide me to do this plz!

hi there :)

we need lots more info from you, you have given us nothing to go on.
what are the frequencies ?
what sort of bandwidth do you need/expect ?
what signal levels in volts or dBm ?
what is it that you want your project to actually achieve ?
is this RF or AF ?

etc etc

cheers
Dave

hi dave

i am doing dualband filter for RF, frequencies 1.8/5.8 GHZ using ADS.. i heard that, for the impedance matching dual frequency transformer may used but i dont know the concept behind this. is it neccesary? then how to do that? i hav done the remaining portion of this filter..