triple_core
Joined: 18 Jun 2007
Posts: 41
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 03 Nov 2009 11:29 DC current of class AB Power Amplifier? |
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Hi,
The DC current of class AB Power Amplifier is according to the power level, as power increases, the DC current increases also.
But for different PA, the slope of the DC current increase is not the same. E.g. when 2 different transistor is biased by the quiscent current of 100mA, they have different DC current at 20dBm, 30dBm.
Does anyone know, which parameter determines this characteristics? Do I have any possibility to tune it?
Thanks in advance!
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vfone
Joined: 10 Oct 2001
Posts: 2329
Helped: 327
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03 Nov 2009 13:59 Re: DC current of class AB Power Amplifier? |
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If the gain of the transistors is different, the DC current consumption will be different for the same output power.
Different transistors can have different collector/drain efficiency for same output power.
For gain needs input match tuning and for efficiency needs output match tuning.
Ideally is to use a Load Pull tuning to find the proper values for power, gain, and efficiency.
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