A Class E/Fodd Power Oscillator Incorporating a Distributed Active Transformer

A power combined high-efficiency oscillator is proposed using a hybrid class E and class F tuning, where the odd harmonics are shorted: the class E/F
_odd
. The oscillator is achieved by adding a high-pass feedback network to a class E/F
_odd
amplifier, where the output's odd harmonics are used to construct the required square-like wave at the input. Furthermore, two class E/F
_odd
oscillators can be power combined using a distributed active transformer, where magnetic coupling to the high-pass feedback network can be realized using a third transformer winding. Two power combined class E/F
_odd
oscillators designed using this method have an oscillation frequency of 10.1 MHz, a total output power of 324 W and dc-to-RF conversion efficiency of 75%.