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Design >> RF Design >> Why filter in front of LNA should be terminated with 50Ohm ?
https://designers-guide.org/forum/YaBB.pl?num=1215709579

Message started by Julian18 on Jul 10^th, 2008, 10:06am

Title: Why filter in front of LNA should be terminated with 50Ohm ?
Post by Julian18 on Jul 10^th, 2008, 10:06am

Hi, there
Anyone want to explain for me why we should terminate a filter with 50Ohms? what if we dont and what is the effect? where can I get this kind of information?

Title: Re: Why filter in front of LNA should be terminated with 50Ohm ?
Post by ACWWong on Jul 11^th, 2008, 6:22am

If you mean SAW filter, then the filter characteristic is only guaranteed for the passband if the VSWR in the passband is low, so it needs to be matched. The SAW filter data sheets usually specify the specification.
Generally, RF filters need to be terminated in the correct impedance for the characteristics to be defined/maintained