AM/AM,AM/PM questions

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e971

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1...what is AM/AM? and AM/PM? show me the details abt that......
some tutorials or pdfs about that are welcome......
2...how can i measurement AM/AM and AM/PM characteristics of PA?
show me the details.......some urls are welcome
3...what is "non-constant envelope signals " ?for example, p/4 QPSK and
16 QAM signals? and what is constant envelope signals?

thax in advance!!!!!!!!!!!!!!
 

These are types of distortion added to signals by amplifiers and other circuits. The first term in the x/y format is the property of a perfect signal. The second term is the type of imperfection added by the circuit.



As far as envelopes, different modulation types only change the phase or frequency of a signal. MSK and FSK are examples. Other modulation types change the amplitude and possibly the phase as well. filered PSK and QAM are examples.
 

AM/AM : caused by device nonlinearity, the amplitude magnitude variation on input signal will cause the output signal magnitude nolinear change, for example, gain compression.You can test AM/PM by single frequency power sweep than check its output amplitude information. As a general case, power supply always a source of input amplitude variation.
AM/PM : sames as AM/AM , only differenc is its influence on output phase.Will cause spur spectrum.
 


thank pewang
and the source of the asymmetry of the IMD is what?
how can i avoid the asymmetry of the IMD?
any papers abt that are welcome
thanx alt
 

The only literature I know about this topic is Cripp's Advance Techin RF Amplifier Design,you can download this book from forum "ebook upload and download"
Best Regards!
 

pewang said:
The only literature I know about this topic is Cripp's Advance Techin RF Amplifier Design,you can download this book from forum "ebook upload and download"
Best Regards!
Click to expand...

i got it, bt my points are no enough
 

You can download mirror with no point.But maybe need wait for half month away from the post day.
 

Another good source of AM/PM,AM/AM measuremen
 

pewang said:
Another good source of AM/PM,AM/AM measuremen
Click to expand...
Dear PeWang:
thanks for u's share.bt when i browse chapter 4.5-4.8, these files are missing......this chapter 4 comes from the book"The RF and Microwave Handbook" ?
Editor in Chief Mike Golio Boca Raton: CRC Press LLC,2001

thx alt
 

Yes,you are right.I also missed the chapter4.5~4.8.
You can download this book from MCU or search in the ebook forum.
Best Regards!
 

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