All the class e component values were obtained from a class e design tool. Notice the RLC LPF at the output. This performs two functions; removing the high order harmonics as well as acting as an impedance matching network to convert the 50 ohms load to 25 ohms for a minimum power dissipation. The calculated efficiency was around 90%; is this the actual efficiency of this circuit?
Edit 1:- Thanks @zorgrian! You seem to be right. After meddling with the RF choke, I reached a point when the power dissipation is the least. This works very well, although a lower inductance shifts the wave slightly towards the negative side. 10uH works well but the efficiency is reduced in that case, coz the current transient is steeper. Also, the starting time has been improved. With 10uH, there's enough time to discharge the stored energy so that the output voltage can soar even higher.
Edit 2:- Used trial/error to figure out the right cap value at which the resonant tank, influenced by the low-value inductor, causes a minimum overlap of current and voltage. Thanks for introducing this new idea, @zorgrian.
Edit 3:- So which one actually wins in terms of efficiency? More importantly, I dunno to calculate the efficiency of this amp.
Edit 4:- Among the last two, the 2nd one is the most efficient one, with an efficiency above 92%. The last one only has an efficiency around 62%, coz the choke was too small to limit the current through it.
