Wideband class-e amplifier

A class-E radiofrequency, RF, amplifier, comprising:

• a power transistor configured to receive an input signal having a predetermined duty cycle, the power transistor comprising an output and an output capacitance Cout;
• and
• a class-E network connected to the output of the power transistor, wherein the class-E network is configured to present a frequency-dependent impedance over a given operational frequency band at the output of the power transistor,
• wherein (i) the combination of the impedance of the class-E network seen at the output of the power transistor and the output capacitance Cout matches, over the operational frequency band, (ii) an impedance profile that has been constructed using a model for a generalized class-E amplifier, wherein the model comprises a switching element and a generalized class-E network including a shunt capacitive network connected to an output of the switching element,
• wherein, for each operational frequency ω within the operational frequency band and given a q factor of the generalized class-E network, a set of component values for the generalized class-E network for realizing class-E operation of the generalized class-E amplifier with non-overlapping current and voltage waveforms is uniquely defined,
• wherein the generalized class-E amplifier utilizes:
• at a target operational frequency ω0 within the operational frequency band, a predefined q factor in a range between 1.2 and 1.4 and the shunt capacitive network of the generalized class-E network having a capacitance C that equals a target capacitance C1,3, and
• at other frequencies ω in the operational frequency band, using corresponding sets of component values, a different q factor such that the resulting capacitance C of the shunt capacitive network at those frequencies equals the target capacitance C1,3, and
• wherein the predefined q factor lies in a range between 1.25 and 1.35.