Post subject: P1dB definition Posted: Mon May 18,
2009 9:31 am
Joined: Wed Aug 16, 2006
In the data-sheets
the P1dB for an amplifier or mixer is defined for at single frequencies.
Take the case of a UWB signal of say 500 MHz bandwidth centered
at an LO signal of 4.9 GHz where have a power distribution such
that all frequencies component from 4.65 GHz to 5.15 GHz have same
amplitude level. Consider that the amplitude levels are just below
the P1dB rating at the respective frequencies for a given amplifier.
my question is
1. Will the device saturate?
2. If yes
then how do we find the maximum power that can be applied to the
device input before it reaches saturation in the presence of such
Post subject: Re: P1dB definitionPosted:
Mon May 18, 2009 8:23 pm
Jun 27, 2005 2:02 pm
P1dB by definition is frequency selective, that means it
is defined only per single frequency. If you want to know the P1dB
characterstic of your amplifier for a wide band of frequencies,
you have to measure it for each frequency.
If your BW is
very wide, you can measure the P1dB for small frequency spacings
and assuming that the device's flatness is relatively small, you
can interpolate the P1dB for the frequencies in between.
saturation occurs after P1dB has been reached.
is a term called back off, which is defined as
P1dB(in) - is the P1dB
level at the input (measured).
Pin(actual) - actual provided
If the backoff which you get is positive, then
you are away from P1dB and therefore far from saturation.
Post subject: Re: P1dB definitionPosted: Tue
May 19, 2009 10:56 am
Joined: Thu Sep
25, 2003 1:19 am
Is it possble
to add the tone power to LOG(N).?
N= number of channels