Why is (b_nXa_n^*b_n^*Xa_n) pure imaginary?

1. Why does the available power equal abs(b)^2-abs(a)^2? •

2. Re: Why is (b_nXa_n^*b_n^*Xa_n) pure imaginary?

Pin is the Power which is entered into circuit.Pavs is Available Power from Source.
They are obviously different.If Pr is zero ( conjugate matching ) all power available from the source enters into circuit. •

3. Re: Why does the available power equal abs(b)^2-abs(a)^2? Originally Posted by ruwan2 Then, it has another equation:
Equations are wrong.
Pavs has to be Pin. •

4. Re: Why does the available power equal abs(b)^2-abs(a)^2?

To start with we should clarify some terminology:
Pavs (aka the available, incident, exchangeable power from the source)=|a|²
Pr (reflected power)=|b|²
Pin (absorbed, transmitted, or actual power) =|a|²-|b|².

So the equation in the first attachment is fine: Pin=Pavs-Pr.

But the second attachment is completely off. I'm not even sure why the condition ΓLS* is relevant. That doesn't have anything to do with conjugate match condition...

- - - Updated - - - Originally Posted by pancho_hideboo Equations are wrong.
Pavs has to be Pin.
I'm guessing that here "Pin" doesn't mean "incident" power, but rather power absorbed by the load... I know, very sloppy. --[[ ]]--