Re: [Qucs-help] square law detector from experimental data

[kochab <ko...@gm...>]

On 5/13/07, Stefan Jahn <st...@gr...> wrote:
> Am So, 13.05.2007, 01:17, schrieb kochab:
>
> > Hi!
>
> Hello there,

Thank you very much for your answer,
>
> I am not sure about the actual problem here.  But I can tell two
> things:  During AC analysis the AC power sources emit the given
> available power "P" which are set to "0dBm" (1mW) in your example.
> Probably you want to change this.

The radiometer has to be sensitive to the temperature of the input
load, therefore I regulate the input power by changing the temperature
of the input resistance, which in this case is 200 K.
Then I look only to the noise and not to the signal.

>The second thing: If DET.s2p
> is meant to be a signal amplifier then have a look at "out.v" instead
> of "out.vn".

The problem with DET is that it is a nonlinear amplifier, actually a
square law detector, for which I have an experimental transfer
function between input power (W) and output Volts.
Therefore I cannot use the 2 port Sparameters component because it
works between input signal (V) and  output signal (V).
Therefore I would need to compute the power, V^2/50 and then apply the
experimental transfer function which characterize the detector.
Is there a way to do this in QUCS?

>
> Hope this helps,
>   Stefan.
>

Thanks,

Andrew