Voltage feedback for series connected microwave amplifiers

摘要

A microwave power amplifier is comprised of a plurality of series connected amplifier stages. Each stage is provided with a local negative feedback. The addition of the local voltage feedback distribution networks provide correct voltage distribution and equal current distribution for all transistors, such that the peak-to-peak voltage and current swings of each transistor can be set simultaneously to the values required for efficient amplifier operation. The method applies to both FETs and bipolar transistors. The series connected microwave power amplifier is thus characterized as a stack with local voltage feedback networks which provide an equal distribution of voltage across the transistors in the stack. The amplifier stages can be biased and tuned to collectively operate either as a class A or B amplifier.