didac wrote on Jun 4^th, 2008, 2:57am:

I don't understand a meaning of "apparent" power.
Do you mean reactive power ?

Assume a situation where output of DUT is connected to didac wrote on Jun 4^th, 2008, 2:57am:

I don't understand a mean of "apparent" power.
Do you mean reactive power ?

Assume a situation where output of DUT is connected to load impedance(=z) by very short line(volatge is uniform over line length).

You can calculate true power delivered to load by knowing voltage of line and load impedance(=z). Here voltage is measured by infinite input impedance probe.

This is a same method as a definition of dbm() function in Agilent ADS.
  Syntax : y = dbm(voltage, z)
  Examples :
     y = dbm(100) returns 50
     y = dbm(8-6*j) returns 30
            Here z is omitted and it is assumed as 50Ohm.

didac wrote on Jun 28^th, 2008, 2:06am:

How do you define and calculate power without knowing current or impedance ?

didac wrote on Jun 28^th, 2008, 3:28am:

What do you mean by the above statement ?

Complex power is defined as
   V*conj(I)=abs(V)**2/conj(Z)=conj(Y)*abs(V)**2
   conj(V)*I=conj(Z)*abs(I)**2

didac wrote on Jun 28^th, 2008, 4:07am:

What do you mean by "the modulus of a waveform" ?

Considering energy conservative system, you need two quantities, "Potential" and "Flow".
In electrical system, Voltage is "Potential" and Current is "Flow".

So even though you know V(t)=Real[(Vi(t)+j*Vq(t))*exp(j*omega*time)], you can't define power without knowing current or impedance.

But as normalized power, you can use 1 Ohm.
The following is a normalized power in assuming load=1.0Ohm.

RMS[V(t)]**2=0.5*{RMS[Vi(t)]**2 + RMS[Vq(t)]**2}
So you don't have to know Vi(t) and Vq(t), that is, phase.
You only have to know envelope level.

didac wrote on Jun 28^th, 2008, 8:30am:

What do you want to do ?
Do you want to define Tevenin equivalent source circuit ?