UHF bandpass filter

[tuyoleni]

Hi guys

I am struggling with a UHF band pass filter. Here are the specs:

Passband frequency range: 416 - 458 MHz
Center frequency: 436.5 MHz
Stopband attenuation: 60 dB
Loss: 1 dB or better
Filter order: 3

I have done the simulation in Filter solutions and when I buid it it doesnt work. I please want if somebody can do the simulation in MWO office and see how it looks like. I am not experienced with MWO. Any suggestions are welcome.

Your comments and help will be highly appreciated.

Thanks in advance

 

[kalbun]

Hello, this message is quite old, but I'll post an aswer nonetheless.
I passed your filter data to Elsie, the software we use for this kind of work.
Here are the resulting components. It's a Cauer filter, 3rd order, that meets your specifications, and the components' values seem reasonable.

1st parallel LC: 68pF, 2nH
1st series LC: 1pF, 54 nH
2nd series LC: 2p4, 136nH
2nd parallel LC: 68 pF, 2nH
Zi=Zo=50R

Hope this helps... :smile:
Giuseppe

 

[feilong87]

Can you give a circuit diagram and some pictures about that?
And Stopband frequency range?
thanks.

 

[Tomas1707]

feilong87, when you write, it doesnt work, you mean in the device which it is designed for, or you measured it by scalar or spectral analyzer?

 

[sv1437]

Hi feilong87, did you get your UWB filter to work ?

And kalbun (Giuseppe), I used the inductor and capacitor given by you in the earlier post , I don't see a UWB response.

See the attached schematic and the frequency response.

 

[chaitanya4]

please...provide the formulae you have used to find inductor and capacitor values