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e971
Joined: 15 Nov 2003
Posts: 38
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 03 Dec 2003 14:11 AM/AM,AM/PM questions |
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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!!!!!!!!!!!!!!
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flatulent
Joined: 19 Jul 2002
Posts: 4856
Helped: 292
Location: Middle Earth
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| 03 Dec 2003 16:06 Re: AM/AM,AM/PM questions |
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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.
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pewang
Joined: 19 Feb 2003
Posts: 139
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Location: China PRC
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| 04 Dec 2003 3:11 |
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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.
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e971
Joined: 15 Nov 2003
Posts: 38
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| 04 Dec 2003 5:39 |
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| pewang wrote: |
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
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pewang
Joined: 19 Feb 2003
Posts: 139
Helped: 1
Location: China PRC
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| 04 Dec 2003 5:55 |
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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!
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e971
Joined: 15 Nov 2003
Posts: 38
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| 04 Dec 2003 6:05 |
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| pewang wrote: |
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
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pewang
Joined: 19 Feb 2003
Posts: 139
Helped: 1
Location: China PRC
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| 04 Dec 2003 7:09 |
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| You can download mirror with no point.But maybe need wait for half month away from the post day.
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marcomdd
Joined: 11 Jan 2003
Posts: 158
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| 04 Dec 2003 8:21 Re: AM/AM,AM/PM questions |
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A paper....
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e.b
Joined: 17 Sep 2002
Posts: 1
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pewang
Joined: 19 Feb 2003
Posts: 139
Helped: 1
Location: China PRC
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| 05 Dec 2003 6:40 Re: AM/AM,AM/PM questions |
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Another good source of AM/PM,AM/AM measuremen
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e971
Joined: 15 Nov 2003
Posts: 38
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| 05 Dec 2003 16:14 Re: AM/AM,AM/PM questions |
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| pewang wrote: |
| 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
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pewang
Joined: 19 Feb 2003
Posts: 139
Helped: 1
Location: China PRC
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| 07 Dec 2003 2:14 |
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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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