Reflections when conjugately matched

[circuitking]

Hi, as per Pozar's Microwave Engineering book, there is a condition
"A special case of the transducer power gain occurs when both the input and output are matched for zero reflection (in contrast to conjugate matching). Then GammaL = GammaS = 0" then GT=S21^2.
And another one is conjugate matched condition.
Does this mean ever after performing conjugate matching, there will be still reflections?. Could someone explain the difference between these two conditions.

Thanks in advance.

 

[pancho_hideboo]

Does this mean ever after performing conjugate matching, there will be still reflections?.

Voltage wave is reflected.

Could someone explain the difference between these two conditions.

Surely read and learn Power wave in Pozar’s Book, before EDA Tool Play.

See the followings.
https://www.edaboard.com/showthread.php?378353#5
https://www.edaboard.com/showthread.php?378353#20

 

[mtwieg]

Hi, as per Pozar's Microwave Engineering book, there is a condition
"A special case of the transducer power gain occurs when both the input and output are matched for zero reflection (in contrast to conjugate matching). Then GammaL = GammaS = 0" then GT=S21^2.
And another one is conjugate matched condition.
Does this mean ever after performing conjugate matching, there will be still reflections?. Could someone explain the difference between these two conditions.

Thanks in advance.

There's a subtle distinction between travelling waves (aka voltage waves) and power waves. For travelling waves, the reflection coefficient is defined as Gamma=(ZL-Zs)/(ZL+Zs). For power waves, Gamma=(ZL-Zs*)/(ZL+Zs). So for a conjugate match, the power wave reflection coefficient will be zero, but the travelling wave reflection might not be.

 

[BigBoss]

Researched in my literature and found very intuitive explanation about Power Waves and Scattering
"Microwave Transistor Amplifiers-Analysis and Design"-Guillermo Gonzalez Section 1.7 pp:45-60