Systematic waveform engineering enabling high efficiency modes of operation in Si LDMOS at both L-band and S-band frequencies

This paper demonstrates that by robust waveform engineering it is possible for high power Si LDMOS to achieve very high efficiency at frequencies up to 2.1 GHz. Class F amplifier operation was realized in a 5 W LDMOS device by the successful application of robust waveform engineering procedures; undertaken at the current generator plane. The peak power added efficiency was found to be 78% at 0.9 GHz and 77% at 2.1 GHz. In both cases the RF waveforms were optimized in terms of the gate voltage, fundamental and harmonic impedances. The main difference at 2.1 GHz was the change in fundamental impedance to a more reactive impedance to compensate for the dynamic device output capacitance. To the authorspsila knowledge this is the highest efficiencies reported in the literature for Si LDMOS devices at 2.1 GHz.