May 12, 2008 #1 S shahid78 Full Member level 5 Joined Jul 29, 2006 Messages 288 Helped 34 Reputation 68 Reaction score 14 Trophy points 1,298 Activity points 3,294 i am a bit confused on interpreting the scattering parameter results shown by network analyzer for example the S11 shown by network analyzer for any antenna is in dB. now if i want to calculate the abosulte values which formula should i use S11(dB)=20 log ( S11) or S11(dB)=10 log (S11) any help will be highly appreciated regards
i am a bit confused on interpreting the scattering parameter results shown by network analyzer for example the S11 shown by network analyzer for any antenna is in dB. now if i want to calculate the abosulte values which formula should i use S11(dB)=20 log ( S11) or S11(dB)=10 log (S11) any help will be highly appreciated regards
May 15, 2008 #2 P Phytech Full Member level 3 Joined Apr 30, 2008 Messages 177 Helped 49 Reputation 98 Reaction score 35 Trophy points 1,308 Location USA Activity points 2,145 The first one
May 19, 2008 #3 citizen Member level 5 Joined May 14, 2008 Messages 90 Helped 3 Reputation 6 Reaction score 0 Trophy points 1,286 Activity points 1,867 thank you, i was also have this doubt .
May 19, 2008 #4 A akedar Full Member level 5 Joined Jul 27, 2004 Messages 248 Helped 30 Reputation 60 Reaction score 14 Trophy points 1,298 Activity points 1,180 well S11 is measuring in terms of power so u have to take 10 log formula because S=a/b where a nd b are incident and reflected power waves u can refer to manual it will further confirm
well S11 is measuring in terms of power so u have to take 10 log formula because S=a/b where a nd b are incident and reflected power waves u can refer to manual it will further confirm
May 25, 2008 #5 S Slayerza Full Member level 5 Joined Oct 22, 2005 Messages 295 Helped 27 Reputation 54 Reaction score 5 Trophy points 1,298 Location South Africa Activity points 3,462 I agree since the parameters are measured as power levels it should be the 10log variant. This can easily be derived from the definition of a decibel. Cheers, Slayer
I agree since the parameters are measured as power levels it should be the 10log variant. This can easily be derived from the definition of a decibel. Cheers, Slayer
May 27, 2008 #6 L loucy Advanced Member level 1 Joined Aug 26, 2001 Messages 414 Helped 24 Reputation 48 Reaction score 11 Trophy points 1,298 Activity points 4,657 S-parameter is complex (magnitude and phase) so it cotains more information than the power ratio. In any case, even if you define it as a RATIO of two powers, it doesn't have the unit of power. 10Log is incorrect.
S-parameter is complex (magnitude and phase) so it cotains more information than the power ratio. In any case, even if you define it as a RATIO of two powers, it doesn't have the unit of power. 10Log is incorrect.
May 28, 2008 #7 S sasaberali Junior Member level 1 Joined Oct 5, 2007 Messages 16 Helped 1 Reputation 2 Reaction score 0 Trophy points 1,281 Activity points 1,369 hi 20×log10×s11=s11(db)