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Electronics => RF, Microwave, Ham Radio => Topic started by: madhu.wesly01 on March 26, 2019, 02:09:35 pm

Title: DC blocking caps selection for a Filter(Band pass).
Post by: madhu.wesly01 on March 26, 2019, 02:09:35 pm

Hi,

I am going to use the below Filter in my RF application. One thing I could not understand is: finding out the DC blocking capacitors' values which are recommended as a part of supporting circuit. Please, let me know if I should use the DC blocking caps, if yes, what should be the capacitors values??

https://www.johansontechnology.com/datasheets/0868LP15A020/0868LP15A020.pdf (https://www.johansontechnology.com/datasheets/0868LP15A020/0868LP15A020.pdf)


TIA!

Best regards,
Wesly.

Title: Re: DC blocking caps selection for a Filter(Band pass).
Post by: chrisl on March 26, 2019, 05:50:04 pm

The IN/OUT ports of the filter are DC short to the GND.
If your circuit does not have any DC component on those ports you do not need the DC block caps.
Otherwise 100 pf ~ 200 pf range of caps will do.