sharethewell
Member level 5
Here is a circuit of Class E PA (output stage) with Class F as driver stage. Since both transistors in driver and output stage work in cutoff and triode mode, I am wondering how I can decide the L and C values of interstage impedance matching network for the two modes.
I am guessing for the driver stage transistor. Looking into the this transistor, the impedance I can see is only the drain-source resistance, Rds. Looking into the output stage transistor, the impedance only has to do with Cgs and Cgd. Is this right?
However the output transistor works in two modes, then Cgs and Cgd are different in two modes. That means the input impedance of output stage is different in the two modes (triode and cutoff). Also the Ron of the driver transistor is also different in the two modes. So how can I impedance match the output impedance of the driver stage to the input impedance of output stage because of this?
**broken link removed**
I am guessing for the driver stage transistor. Looking into the this transistor, the impedance I can see is only the drain-source resistance, Rds. Looking into the output stage transistor, the impedance only has to do with Cgs and Cgd. Is this right?
However the output transistor works in two modes, then Cgs and Cgd are different in two modes. That means the input impedance of output stage is different in the two modes (triode and cutoff). Also the Ron of the driver transistor is also different in the two modes. So how can I impedance match the output impedance of the driver stage to the input impedance of output stage because of this?
**broken link removed**
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