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15th August 2019, 07:58 #1
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Why Z and Y matrices must be pure imaginary for reciprocal lossless Nport junction ?
For a reciprocal lossless N port junction,
1) Why is P_{avg} = 0.5*[V]^{ t} [ I ]^{ *} instead of P_{avg} = 0.5*[V]^{ *} [ I ]^{ t} or P_{avg} = 0.5*[ I ]^{ t} [V]^{ *} ?
2) Why [V] = [Z][ I ] instead of [V] = [ I ][Z] ?
3) If we set all port currents equal to zero except for the nth current , which port will the nth current flow to ? This seems to be related to ports decoupling theorem ?
Note: The following screenshot is from Microwave engineering 4th edition by David Pozar

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15th August 2019, 09:15 #2
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Re: Why Z and Y matrices must be pure imaginary for reciprocal lossless Nport juncti
Hi,
Maybe I don't understand the question.
My answer is: for "lossless" you need "imaginary", because "real" means "loss".
Imaginary: pure lossless capacitors and lossless inductors. No dissipated power, no heat, no loss.
Real: resistors. Every voltage and/or current causes dissipated power = heat = loss.
KlausPlease don´t contact me via PM, because there is no time to respond to them. No friend requests. Thank you.

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16th August 2019, 06:48 #3
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Re: Why Z and Y matrices must be pure imaginary for reciprocal lossless Nport juncti
There is no help, since it is too easy.
This is true for all your posts.
https://www.edaboard.com/showthread.php?385763#5
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