Split frequency high-voltage driver for dynamic load modulated RF amplifiers

Dynamic load modulation is a technique for increasing RF power amplifier efficiency by manipulating a tuneable matching network (TMN) between the RF transistor and the antenna in harmony with the envelope of the transmitted signal. Generally, TMNs are based on varactor diodes with control voltage swings approaching 100 V, but future devices are likely to need far greater. The varactor driver amplifier proposed here uses a split frequency architecture to amplify a 3 MHz bandwidth 3GPP 4G long-term evolution envelope signal. Under these conditions, it can produce a peak voltage of 166 V at a power consumption of 0.7 W.