Class E frequency multipliers

The theoretical operation of class E frequency multipliers has been described without experimental verification by Kozyrev. To provide experimental verification, three class E frequency multipliers were designed according to the Kozyrev theory, and measured and theoretical performances were compared. In each case agreement is poor, showing errors over thirty percent, indicating the need for further research. New and complete analyses are performed on two class E circuits: that with a radio frequency (RF) choke in the d.c. supply lead, and that with an arbitrary but smaller reactance replacing the RF choke. For both cases the optimum operating point (100% efficiency at maximum power output capability) is determined for operation at any harmonic, including the first, and equations which yield the requisite component values and resulting operating parameters are given. These equations provide an easily used repeatable design method for constructing class E frequency multipliers. The theoretical design methods exhibit excellent agreement with observed operation, with errors in the range of four to twelve percent.