A Class C Power amplifier in CMOS
时间：04-04
整理：3721RD
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Hi,
I'm trying to implement a power amplifier in Class C but I have some doubts how to evaluate correctly if the power amplifier is working like a real Class C power amplifier.
I need a Class C because I want to build a Doherty PA.
I put the polarization of the bias less than Vth, but I don't know if is enough to guarantee it is working like a true class c.
Because in some forums I've read to work with strong Class C is better but I need to put negative polarization, but when I do the OCP1 it has a behavioal very nonlinear.
And, I'd like to know if Can I evaluate the Class C PA using the OCP1 like a linear PA ? The OCP1 is the metrics correctly to work in this case?
I'm trying to implement a power amplifier in Class C but I have some doubts how to evaluate correctly if the power amplifier is working like a real Class C power amplifier.
I need a Class C because I want to build a Doherty PA.
I put the polarization of the bias less than Vth, but I don't know if is enough to guarantee it is working like a true class c.
Because in some forums I've read to work with strong Class C is better but I need to put negative polarization, but when I do the OCP1 it has a behavioal very nonlinear.
And, I'd like to know if Can I evaluate the Class C PA using the OCP1 like a linear PA ? The OCP1 is the metrics correctly to work in this case?
Class C power amplifier (by definition), IT IS very nonlinear.
Yes I know, because of that, how I mentioned before I don't know what metrics to use to evaluate the parameters like gain, power and etc correctly of the Class C.
As a class C does not amplify small signals,low levels cannot be used. It would be better to calculate the maximum dissipation of the amplifier, then drive it to this point, then find the Pin, Pout then the gain. Just check that the devices maximum I or V are not being exceeded at this point. Remember that the RF voltage will swing to twice the DC supply when the device is switched off.
Frank