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Si14
Nov4-10, 06:14 PM
Hello,

I wonder if there's any difference between the "impedance matching" and "maximum power transfer" criterion?
I assume in both cases, one impedance should be designed to be the complex conjugate of the other.

Thanks.

dlgoff
Nov4-10, 06:37 PM
By PERFORMING impedance matching you can maximize power transfer.

Wiki says,

...impedance matching is the practice of designing...

Impedance matching (http://en.wikipedia.org/wiki/Impedance_matching)

gnurf
Nov5-10, 10:06 AM
I wonder if there's any difference between the "impedance matching" and "maximum power transfer" criterion?
I assume in both cases, one impedance should be designed to be the complex conjugate of the other. Why don't you sketch up a simple circuit with a source that has an internal impedance of your choice, and see how various load impedances affect the power transfer?

Bob S
Nov5-10, 11:38 AM
A quarter-wave transformer (quarter wavelength of transmission line) between the source and the load can maximize power transmission by mismatching the load to the coax. See

http://en.wikipedia.org/wiki/Quarter_wave_impedance_transformer

For example, a quarter wave of 50-ohm transmission line can match a 100-ohm source to a 25-ohm load.

Bob S