Dual Band pass filter design using microstrip...

[varunshana]

Hi every one. Iam varun shana. Iam doing my project named

Design of a Dual band pass filter using microstrip for Wimax .

All about my project is to design a dual band pass filter having two frequency pass bands at output graph. I was given;

center frequencies: 3.5 and 5.8 GHz

All the values can be assumed.

All i need is a schematic diagram in ADS and also the layout that can be converted and the graphs...

I kindly request all my brothers to help me get out of my work as soon. I appreciate if any one can attach any files regarding...

Thanks

 

[biff44]

how many connector ports, 2 or 3?

 

[eee100]

You can use design guides in ADS and design your own filter. After that you can run optimizations in the software to obtain output characteristics as you wish.

 

[varunshana]

i need to use two connector ports... And also i was given 50ohms as the impedance for all the transmissionlines. Please orward me any o the required documents relating to my topic... Hope or your positive reply as soon....

 

[eee100]

Which type of PCB are you planning to use?

 

[varunshana]

iam not gonna use any kind og PCB board. All i have to do is to design a schematic of dual BPF and simulate in ADS and get the required graph at centre pass band frequencies 3.5 and 5.8 GHz. pls help me mate. Atleast gimme someidea how to do or else ple reply me with the schematis....

 

[eee100]

Well to adjust the traces' impedance to 50 ohms you need to know what type of board you will use and find out its dielectric constant at least. Then you run LineCalc utility of ADS and put in your board's electrical values and calculate needed trace width for 50 ohms. As I told you before you can use design guides available in ADS to design your own filter. You can check out help files as well.

 

[varunshana]

mine is a RT Duroid with dielectric const 0f 10.8 and height and loss tan of assumed measurements. pls arrach a file of schematic for my sake.

Added after 1 minutes:

what i had an idean about my work is to take a total o 5 trans lines including i/p and o/p ports.

 

[eee100]

I am sorry but I don't have any schematic. I hope someone has for you. I believe that with some effort you can design your filter. Good luck.

 

[biff44]

you could take a couple of approaches.

1) design a 3 to 6 ghz bandpass filter, and then put a stopband filter at 4-5 GHz in series with it.

2) design a 3.5 ghz bandpass filter using halfwave resonators, and do someting to the resonators so that they also resonated at 5.8 GHz. A 3.5 ghz resonator will naturally resonate again at 7 ghz, so you will have to do something to screw up its second order passband, maybe some lumped L-C loading on each resonator that kicks in at the 2nd passbnad, but is open circuited at the 1st passband.

3) Design some sort of re-entrant resonator bandpass that has a first and 2nd passband.

4) design a 3.5 ghz bandpass, and place a 5.8 ghz bandpass in parallel. A little tricky, since the out-of-band input impedance of one filter has to cancel the reactive part of the in-band filter's, and vice versa.

 

[PeterMartin]

If you were allowed three ports , you would essentially be designing a diplexer with a BPF on each arm.

If you wanted just two ports you would also join the two outputs together and end up with a common junction on both the input and output.

Getting the common junction to be correct is the most tricky part of diplexer design but as the frequencies in your case are well separated it shouldn't be too hard.

 

[Fano Austin]

Hi Varunshana,

I just joined this group and noticed that you are battling with the same project that I am researching on. Even the frequencies are the same. I wish to know how far you have gone with this project (Design of a microstrip dual band filter for WiMax).

Cheers!
Fano

 

[PeterMartin]

Just to make my previous post a bit clearer this diagram shows a dual filter.

Start off by designing each filter separately in a circuit simulator such as ADS, MWO or Eagleware. Then connect them up with 50 ohm lines and adjust their lengths so that the two filters don't interact.

Its not too difficult unless the two filters are very close together in frequency and then it gets a bit tricky.

 

[bommineni]

hai varun

i am working on "design of bandpass filter on microstrip for uwb lower-band"


kindly help me on this topic

 

[volker_muehlhaus]

i am working on "design of bandpass filter on microstrip for uwb lower-band"

kindly help me on this topic

There was an excellent overview paper of UWB band pass filters, with many examples, in the June 2010 issue of IEEE Microwave Magazine (Vol. 11, Number 4, June 2010). This describes and compares the different topologies.