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MOS Class E PA Zout question

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xoneftws

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Hello Everyone!
I have a question about Class E PA, this picture is the schematic of typical
MOSFET Class E PA, if the frequency of the RFIN port is 13.56M and this port's
Zout is unknown, but I want to match the RFOUT port's Zout = 50 ohm, how can I do ?
1.JPG
 

Class-E Power Amplifiers are not designed as classical linear amplifiers.Therefore, a design methodology has been developed by its invertor ( Nathan. O. Sokal ).
Search the internet to find some useful articles and papers about this structure and use a simulation program to do that.
**broken link removed**
 
I don't know from where you got the schematic, but I am afraid this is not a Class-E.
In Class-E topology Cc actually is not a DC coupling capacitor, but it is resonating with L2 on the fundamental. C1 shouldn't exist in that place.
To match the low impedance of the output transistor to 50 ohms load, you can split L2 in two virtual series inductors and use one of them together with C2 to build an L match.

See page 8:
http://www.ixysrf.com/pdf/switch_mode/appnotes/4apprf_1150.pdf
 
Hello BigBoss & vfone!
I recently I study the Class-E Power Amplifiers, and I read many articles, but I still can't understand how to get the Zout. Many articles say use load-pull measurement can get the result, but I just have a network analyser, a spectrum analyzer and an oscilloscope, how can I do ?

Thanks vfone's data, this article say the output inpedance is 8 ohm then match it to 50 ohm, so why the output is 8 ohm?

Attachment contains an article about aplifier and a picture of
common Class-E topology. I found different articles say the
class-E PA topology are not same.

Attachment:
class-E.JPG
 

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  • ClassDEF1.pdf
    170.2 KB · Views: 93

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