T Post subject: Conjugate match Unread post Posted: Sun Jan 16,
2005 4:36 pm Hello all, What is the reason of matching
a network to a conjugate match? I know that the conjugate is
the inverse of the phase for a given match. When is there a need
to do the matching to the conjugate value? Thanks, - T
Top Len Post subject: Conjugate match Unread
postPosted: Sun Jan 16, 2005 6:03 pm Theoretically, a complex
conjugate match results in maximum transfer of power from the source
to the load. Len Top Old Tele man
Post subject: Unread postPosted: Mon Jan 17, 2005 12:15 am Offline
Captain Joined: Sun Oct 17, 2004 1:07 am Posts: 6 Location:
Tucson, AZ maximum power occurs because with a purely RESISTIVE
load no energy is "stored" so as to create standing/reflected waves...
_________________ Devil sez: "...Yes, but it's a DRY heat!"
Top Profile Guest Post subject: Unread postPosted:
Thu Jan 27, 2005 12:34 am Why conjugate? If Xsource = -Xload
then it is resonant and only the source and load resistances influence
power transfer. Top Old Tele man Post subject:
Unread postPosted: Thu Jan 27, 2005 11:14 pm Offline Captain
Joined: Sun Oct 17, 2004 1:07 am Posts: 6 Location: Tucson,
AZ conjugate implies "paired completion"...as: When XL = -XC, the
two vectors "cancel" each other, leaving a purely resistive (R) load...and
NO energy is "dissipated" in either the capacitive- or inductive-reactance,
it ALL goes to the resistive (R) load. _________________ Devil
sez: "...Yes, but it's a DRY heat!" Top Profile
Oleg Pozdeev Post subject: Re: Conjugate match Unread postPosted:
Tue Feb 08, 2005 4:10 pm Len wrote: Theoretically, a complex
conjugate match results in maximum transfer of power from the source
to the load. Len I failed to find a thorough prove
for conjugate match approach, the one published in school books seems
a bit too artificial to me. I'd suggest an exercise in math. A
passive 2-port is described by Y matrix and on left hand side is connected
to source with impedance Zs, while on right hand side is connected to
load with impedance Zl. The power transfer function G(Zs,Zl) can
be derived analytically, and takes max value when dG(Zs,Zl)/dZs=0
and dG(Zs,Zl)/dZl=0 simultaneously. One can take a step further
to check whether the solution relates to max (not a min) value. Under
conjugate match condition there is no reflection between source and
2-port likewise between 2-port and load. The suggested approach gives
similar result if and only if a 2-port is a purely reactive one.
Posted 11/12/2012
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