J0hn
Member level 2
microstrip low pass filter design
Just wonder beside step impedance and elliptic, is there any topology that is compact enough to design microstrip low pass filter, i trying to make the length of the filter to be less than 15mm.
I had attempt to use Alumina (10 mil thick) as substrate, to do a low pass filter at which the bandpass is up to frequency 4.5GHz, but then the problem is that the inductance line of this kind of filter is very long, and i had try to bend the inductance line in order to make it compact. Beside that i trying to hit a rejection of -50dB at 5.1GHz, in order to do so, i have to increase order, but then these will cause the filter to be very big. I also try to design a bandstop filter in order to meet the rejection, but is too big to be used, so i give up on that idea.
Anyone can advise me how to make the microstrip filter as compact as possible and yet meet the rejection? Thanks.
Just wonder beside step impedance and elliptic, is there any topology that is compact enough to design microstrip low pass filter, i trying to make the length of the filter to be less than 15mm.
I had attempt to use Alumina (10 mil thick) as substrate, to do a low pass filter at which the bandpass is up to frequency 4.5GHz, but then the problem is that the inductance line of this kind of filter is very long, and i had try to bend the inductance line in order to make it compact. Beside that i trying to hit a rejection of -50dB at 5.1GHz, in order to do so, i have to increase order, but then these will cause the filter to be very big. I also try to design a bandstop filter in order to meet the rejection, but is too big to be used, so i give up on that idea.
Anyone can advise me how to make the microstrip filter as compact as possible and yet meet the rejection? Thanks.