PM Conversion

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ajhsu

Joined: 04 Apr 2004
Posts: 224
Helped: 3

25 Feb 2005 5:20 am to pm conversion

Could anyone please tell me what does these spec. mean?

AM/AM conversion--Typ:8% , Max:12%
Conditions:5<Pout<34dBm; 6.5% AM modulation with fmod=67kHz at Pin

AM/PM conversion--4deg/dB
Conditions:-0.5<Pin<0.5dBm, 5<Pout<34dBm;

Regarding AM/AM conversion, what does %8 mean?
Regarding AM/PM conversion, what does 4deg/dB mean?
Thanks.

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25 Feb 2005 5:20 Ads

biff44

Joined: 24 Dec 2004
Posts: 1835
Helped: 244
Location: New England, USA

25 Feb 2005 13:05 am pm conversion

AM/PM is easy. Hook the beast to a vector network analyzer, with some means to monitor output power (directional coupler and power meter between output and netwrk analyzer). Set output power to 5 dBm, read phase, increase output power to 6 dBm, read phase. If the phase difference is < 4 degrees, you are in-spec. Now redo with power at 6 dBm, increase to 7 dbm, is phase difference is <4 dBm...repeat until you are at 34 dBm. You will find the most trouble around the 1dB compression point.

As to the AM/AM, they are talking about how much the gain compresses vs output power. Not quite sure what the % means though.