Limiting Driver for Switch-Mode Power Amplifier

摘要

A switch-mode RFPA driver includes first and second field-effect transistors (FETs) arranged in a totem-pole-like configuration. The switch-mode RFPA driver operates to generate a switch-mode RFPA drive signal having a generally square-wave-like waveform from an input RF signal having a generally sinusoidal-like waveform. To maximize high-frequency operation and avoid distorting the switch-mode RFPA drive signal, the switch-mode RFPA driver is designed so that its output can be connected directly to the input of the switch-mode RFPA to be driven, i.e., without using or requiring the use of an AC coupling capacitor. The first and second FETs of the switch-mode RFPA driver are designed and configured to limit and control the upper and lower magnitude levels of the switch-mode RFPA drive signal to levels suitable for switching the switch-mode RFPA directly, obviating any need for DC biasing at the input of the switch-mode RFPA.

主权项

1. A monolithic microwave integrated circuit (MMIC), comprising:
a first field effect transistor (FET); and a second FET coupled to the first FET in a totem-pole configuration, with a source of the first FET connected to a drain of the second FET at an output node, wherein the first and second FETs are configured and controlled so that the output node can be directly connected to a gate of a depletion mode power FET of an external switch-mode radio frequency power amplifier (RFPA) and are configured and controlled to produce a gate drive signal that is capable of switching the depletion mode power FET on and off without having to first level shift the gate drive signal.