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Design >> RF Design >> Class A/AB/C PAE
https://designers-guide.org/forum/YaBB.pl?num=1390891715

Message started by natnoraa on Jan 27^th, 2014, 10:48pm

Title: Class A/AB/C PAE
Post by natnoraa on Jan 27^th, 2014, 10:48pm

Hi guys,

I have a question. Given a simple bias circuit of a nmos, I would like to check the PAE.

Am running Cadence Virtuoso Spectre and the result is that a simple class C PA gives me lower PAE than Class AB or even Class A? Does anyone know the reason for it?

I have already made sure the power at the 2nd, 3rd harmonics are well below -20dBm and from the PSS function, i checked on PAE and selected the fundamental frequency in which i would like to measure its PAE.

I have also used a simple LC oscillator tank to make sure i've filtered out all the harmonics leaving only the fundamental.

Any help would be appreciated. Thanks!

Title: Re: Class A/AB/C PAE
Post by natnoraa on Jan 27^th, 2014, 10:50pm

and also, Vth is about 0.55V so any biasing point below that I'm taking it as a Class C? at 0.55V it will be a class B?

Title: Re: Class A/AB/C PAE
Post by natnoraa on Jan 29^th, 2014, 7:59am

It's okay guys. I've managed to solve this. Thanks for reading

Natnoraa