Power dividing and combining techniques for microwave amplifiers

A power amplifier comprising:

• nonreciprocal means for subdividing the power of an input microwave signal into N fractions and for isolating the N fractions from one another,
• N substantially identical solid-state power amplifier units for amplifying the N fractions respectively,
• nonreciprocal means for combining the amplified fractions and emitting them as a single output,
• said nonreciprocal power subdividing means including
• an N-port circulator including one input port and N-1 output ports,
• a two-port isomismatch having an input port coupled to each of the N-1 circulator output ports respectively and an output port coupled to a corresponding one of said amplifier units,
• each isomismatch absorbing all signal power input to its output port,
• the isomismatch device coupled to the Nth circulator output port transmitting all of the incident microwave signal power from the Nth circulator port, and
• each of the isomismatches coupled to the other circulator output ports transmitting a predetermined fraction of the microwave signal power incident from the respective circulator port and reflecting the remainder back toward the respective circulator port, to divide the microwave signal power incident to the circulator input port into predetermined fractions that sum to substantially the signal power input to the circulator.