How Power Combiner works?

[Hell Obliviate]

hi guys,

i do not understand the behave of power combiner, if you guys help me to understand it than it would be very good.

here i upload a file, where you can see that output of combiner with coupler is 500uW, but it suppose to 1mW, because each input of combiner is 500uW.

but at when 500uW power is directly connects to the combiner each input then it also give the 1mW out put.

why this is happening, is some thing wrong with the combiner? is it malfunctioning? this is really annoying.

thank you again
hell

[Mohamed A. A. Abouseif]

Hi Hell,
I think, the combiner works perfectly.
I think the difference between the two cases is that; there is a phase shift added to the output of the coupler, (check its Manual) while in the second case the two sources have random phases, that it is why there are some fluctuations of the output power with time.

Note that, the combiner by default add fields (see it Manual) unless the “Force power conservation” unchecked.
if it is checked you will find the two cases gives a stable 1 mW output with time.

Hope this clarify the case,
thanks
Mohamed Abouseif

[Steve Dods]

This is a frequently asked question. So much so that I did a webinar on it. I have attached the written material from the webinar. I hope that helps.

[Steve Dods]

SymmetricCombiner.pdf

[Hell Obliviate]

Hi Abouseif,

it is always good to see you.
your are right! the phase shift is 90 degree.

but i have got couple of questions about this topic, & hopping answer from you again!

1. i uploaded another file, where combiner has 1mW input but its output is 500uW. why combiner attenuated the power when another input is low? it suppose to add them. However when i give both the input same power, it is not happening. why?

2. can you me help about “Force power conservation”, i could not found it in optisystem7.

3. inputs of ideal MUX is 1mW, but output is 4mW, why ideal mux amplify the signal?

thank you again
take care
hell

[Mohamed A. A. Abouseif]

Hi Hell,
attached is the webinar Materials of Steve.

thanks
Mohamed

[Mohamed A. A. Abouseif]

I will try again, as I do not know why it is not uploaded with me as well!

[Hell Obliviate]

Hi Dods,
thanks for replay!
But i could not access your pdf. would you please kindly upload it again?

regards
hell

[Mohamed A. A. Abouseif]

Hi Hell,
please revise Steve materials I am sure it will answer your questions and let us discuss if you have any other concerns.

by the way, I am sorry we do not have Optisystem7.
you can download the trial version of optisystem15 for one month on your machine.

thanks
Mohamed Abouseif

[Hell Obliviate]

Hi Abouseif & Dods,

the document you have suggested is quit helpful, i enjoyed reading it. Finally it is understand that, why combiner behave such.
in theory & simulation it is clear that when a input is very low other arm’s input faces 3dB attenuation.

But i have another query
the option “Force power conservation” you have told, is it possible to implement this option in real combiner?

thank you both again,

have fun 🙂

hell

[Mohamed A. A. Abouseif]

Hell,
when you select Force power conservation that mean it is working as a power combiner so yes it is in real life for sure.

hope this is clear
thanks
Mohamed

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