AM/AM,AM/PM questions

[e971]

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!!!!!!!!!!!!!!

 

[flatulent]

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.

 

[pewang]

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.

 

[e971]

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

 

[pewang]

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!

 

[e971]

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!

i got it, bt my points are no enough

 

[pewang]

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

 

[marcomdd]

A paper....

 

[e.b]

:?: https://www.rohde-schwarz.com :?:

search for "am/pm" or "K70"

regards e.b

 

[pewang]

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

 

[e971]

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

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

 

[pewang]

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!