[SOLVED] 10 Ghz Bandpass Filter

[guytoub]

hi every one !


I want to design a microstrip bandpass filter at 10 Ghz with a narrow bandwidth
i can use ADS to design it but i would like to know which subtrate is the best to design it and which topology i can use.
is it possible with microstrip ?


thanks

 

[biff44]

sure, why not.
microstrip has a limited range of un-loaded Q's for various types of resonators, so if you try to make the bandpass filter too narrow, you will end up with very high insertion loss.

that is why in demanding applications you can still find things like waveguide or dielectric resonator filters. Below 5 ghz, you almost exclusively see high K ceramic resonators making up the N pole bandpassfilters, or other things like SAW or BAW filters for very narrow band.

 

[guytoub]

thank you for your answer, by narrow band I would say about 100 or 200 Mhz of bandwidth

 

[Hawaslsh]

100 or 200 Mhz of bandwidth

At 10Ghz, 100 Mhz is a very small bandwidth for plain microstrip structure, 1%. The simplest microstrip BFP topology you can play with in ADS is a coupled line filter, but you can never achieve that small a bandwidth. I used microwave office, but I am sure ADS has its own coupled line model. I choose a realisticish substrate, er=3.4 , ~20mil thick, 1oz copper. The vertical cursors are 100 MHz BW center at 10 GHz.

not sure if that was helpful

 

[vfone]

The paper below claims that got 100MHz BW at 9.5GHz.
It use high frequency Duroid substrate Rogers RT5880 (Er=2.2, DF=0.0004)

https://iopscience.iop.org/article/10.1088/1757-899X/306/1/012124/pdf

 

[guytoub]

The paper below claims that got 100MHz BW at 9.5GHz.
It use high frequency Duroid substrate Rogers RT5880 (Er=2.2, DF=0.0004)

https://iopscience.iop.org/article/10.1088/1757-899X/306/1/012124/pdf

Thanks Vfone for this paper , i will try it tomorrow .
today i try with the ADS design guide but dond have a good result .